Category: Fighting Dharma

Table of Contents

• Tires
  • Pneumatic
  • Resources
• Tires
  • Tire beads
  • Casing, Sidewalls & Tread
  • Contact Patch, Deflection, Tire Drop, Rolling Resistance
  • Wider, Softer, Supple
• Road Bikes
  • Knobs & Cleats
  • Valves, Chucks, Gauges
  • Pressure – Warnings, Manufacturer Recommendations
  • Industry Testing
  • Consumer-led testing
  • Bicycle Quarterly
  • The Consultant’s View
• My Tires
• Pressure Calculators
  • Generally
  • Silca Velo
  • René Herse

Tires

Pneumatic

Modern tires allow cyclists to ride pavements, gravel, trails, dirt, mud, and other surfaces. Pneumatic tires, pneumatically inflated with compressed air, were invented and industrially produced before the end of the 19th century. Earlier, solid rubber was used to manufacture bicycle tires. It was better than other material. Getting a bouncy wheel that did not keep bouncing was one puzzle. Making the tire durable enough to survive contact with the road was another. Rubber proved to be elasic enough to bounce and deform and durable enough to roll for hundreds of miles.

The use of rubber for tires for automobiles and truck led to developments in material science and manufacturing, and to sophisiticated suspension systems. Suspension systems need to be damped to prevent the repetition of cycles of bouncing. Large industries rested on the discoveries that natural rubber was elastic, and could be used to manufacture devices that would contain compressed air. The development of pneumatic rubber tires for cars and trucks allowed bicycle manufacturers to acquire material and devise ways to mass produce tires. Tires have inspired the invention of tire materials, wheel rims, valves, pumps, tire levers, tools, patches, and adhesives. The newer tubeless bicycle tires have led to tire sealant, tire plugs, and tubeless repair kits.

Resources

Cyclists are interested in evaluating tires and learning which tires are efficient and economical. Tire manufacturers will happily say that they manufacture a product, and that their product is superior to other competing products. Scientific material that explains how tires work is more scarce.

Bicycle Tires and Tubes by Sheldon Brown and John Allen at Bicycle Technical Information (the Sheldon Brown site) is a well constructed page with links to terms and topics covering materials and construction. It discusses tire sizes and dimensions. BikeGremlin also explains Bicycle tyre sizing and dimension standards and other technical issues.

BTI is not a resource for information about mountain bikes. BTI published Jobst Brandt’s 1998 “A Brief History of the Mountain Bike ” which said: “The first successful high quality fat-tire bicycle was built in Marin County, California by Joe Breeze”. BTI has “suspension” in its glossary, but does not explain mountain bike suspension systems. Internet seach engines can find pages about bicycle suspension systems – for instance the Wikipedia entry Bicycle suspension but search engines do not respond fulsomely to queries about losses of energy operating bicycles on rough and irregular terrain due to vibration. There is a section on vibration in the Wikipedia entry Bicycle and motorcycle dynamics and a Wikipedia entry on vibration.

Current and historical Information on tires, rubber, and manufacturing tires available in Wikipedia, including pertinent articles explaining:

• natural rubber, and latex rubber;
• the inventor John Dunlop and the pneumatic tire;
• synthetic rubber
• butyl rubber
• vulcanizing (curing or hardening) tires;
• tire tread;
• rolling resistance.

There do not appear to be standards for how to describe the quality of tires. In a rational world, a manufacturer would have goals in developing new tires and test experimental prototypes and production models. Wikipedia has not found that many industries have adopted methods and standards. Wikipedia, as of June 2022, has pages about

• test methods,
• Quality Management systems, and
• consumer-oriented product testing.

Engineer and blogger Tom Anhalt wrote about tires, tube and pressure at the online triathlon magazine Slowtwitch.com, some listed here, and wrote articles on his own Blogspot blog Blather ’bout Bikes:

• July 2007 Tires and wheels for timed cycling events;
• August 2009 What’s in a Tire;
• September 2009 What’s in a Tube

Derek Lakin writes at site called TreadBikely. It seems to be a commercial site. The site has illustrated articles that discuss tire manufacturing:

• How Bike Tires Work: Your Quick-Reference Visual Guide;
• What Are Bicycle Tires Made Of? A Step-by-Step Exploration of the Manufacturing Process.

Tires

Tire beads

A bicycle tire is a strip of durable and stretchy materials laid out in a circle, with edges pulled up to shape the tire in a U-shape. Most tires have beads, a structural part that is durable but not stretchy:

Conventional tires used on 99% of all bicycles are “clincher”type … They consist of an outer tire with a U-shaped cross section, and a separate inner tube. The edges of the tire hook over the edges of the rim, and air pressure holds everything in place.

….

The “bead” is the edge of the tire. On most tires, the beads consist of hoops of strong steel cable. The beads hold the tire onto the rim, and are, in a sense, the “backbones” of a tire. While most beads are steel, some tires use Kevlar ® cord instead.

Sheldon Brown, John Allen, Bicycle Technical Information, Bicycle Tires and Tubes

Wire beads are less common than they were in the 1980s. Modern bicycle tire manufacturers use synthetic compounds to manufacture tire beads. Synthetic aromatic polyamids (Aramid) are popular. The rim of a clincher wheel is machined to turn inward to hold the bead in a “bead” hook. Clincher tires use an inner tube, which is airtight and inflated. The butyl rubber inner tube is the ordinary tube; latex tubes for clincher tires are available.

Tubeless tires are clincher tires without inner tubes. They have to be airtight to be inflated without inner tubes. The wheel rim is sealed with a airtight rim tape. The valve is sealed to the rim (and not to inner tube, passed through and opening. A tubeless ready tire is a clincher tire with an inner tube. A tubeless ready wheel rim may have tubeless rim tape, but a tubeless ready system has an inflatable inner tube – the valve is attached to the tube. Tires have been securely clinched to the wheel and sealed airtight by matching the bead with a bead hook structure or bead channel in the wheel rim.

Tubeless tires need liquid sealant in the tire to seal the tire to the rim. The liquid sealant is also supposed to block small leaks and punctures, as well as sealing the bead. A rider can carry tools to plug a small puncture and reinflate it if the sealant has remained in the tire and still functions. As of 2022, manufacturers of wheel rims are building and promoting rims without bead hooks for tubeless tires. There are cost savings in manufacturing wheel rims, and time and cost savings in changing tires, at the risk of tires coming off the rim.

A “tubular” tire, not to be confused with a clincher, also uses an inner tube. Tubular tires are explained at BTI. Tubulars are uncommon and mainly found on racing bikes.

Casing, Sidewalls & Tread

The body of the tire, technically called the carcass, commonly referred to as the casing, is made of “threads”, coated with plastic and rubber compounds:

Cloth fabric is woven between the two beads to form the body or “carcass” of the tire. This is the heart of the tire, the part that determines its shape. The vast majority of tires use nylon cord, though some use other polyamides. … The fabric threads don’t interweave with crossing threads as with normal cloth, but are arranged in layers or “plies” of parallel threads. Each layer runs perpendicular to the next layer(s).

Some tires use thick thread, some use thin thread for the fabric. With thin thread, there are more threads per inch (“TPI”) and this number is often considered an important indication of tire performance. The higher the TPI number, the thinner and more flexible the tire fabric is. Thin-wall (high TPI) tires tend to be lighter and have lower rolling resistance, but they’re more easily damaged by road hazards.

Bicycle tires have the threads of the fabric running diagonally, (“bias”) from bead to bead. Modern car tires have the main threads running straight over from one bead to the other, known as “radial” construction. Radial tires will also have a “belt” of plies running all the way around the circumference of the tire, crossing the radial plies.

Sheldon Brown, John Allen, Bicycle Technical Information, Bicycle Tires and Tubes

In automobile and truck tires, the threads are called cords and may be made of metal. The term cords is also used to refer to bicycle tire threads. Few modern bicycle tire threads are not made of natural plant fibers (e.g. flax, hemp, cotton). Most are filaments of petroleum synthetic (i.e. plastic), often nylon, spun into threads. The threads are not woven into a cloth or fabric. Thread count is a (vague) measure of the texture of woven fabrics – particularly cotton bed sheets. Thread count is not generally a selling point for modern bicycle tires, except that high thread count was used by some manufacturers to mean that that a casing is strong and “supple”.

The threads cross each other in a grid, and are coated in an elastomer – a plastic compound. Some machines produce ribbons of the specified width; some machines produce sheets that are cut to ribbons of the required width. The ribbons are folded over the beads and welded. The threads reach from bead to bead, on the bias (diagonally). Layers of rubber or synthetic rubber compound are applied to the ribbon to form the sidewalls and the tread. The tires are pressed into moulds, shaped, and laminated. In some tires groups of threads (belts), are laid down with the bands crossing each other.

The tread is the part of the tire that contacts the road:

… This area usually has thicker rubber than the “sidewalls” of the tire, mainly for wear resistance. Most tires have some sort of 3-dimensional pattern molded into the tread, which may or may not enhance traction.

Manufacturers mix different additives with the rubber to achieve desired traction/wear characteristics. Generally, a softer formulation will give better traction, but at the expense of more rapid wear. Rubber is normally a sort of tan color, but most tires are black. This is the result of adding carbon black to the mix. Carbon black considerably improves the durability and traction of the rubber in the tread area.

Sheldon Brown, John Allen, Bicycle Technical Information, Bicycle Tires and Tubes

A tread pattern of grooves in a thicker tread is common for automobiles. It was common for bicycle tires through the greater part of the 20th century, except for some special purpose tires. Tread patterns on bicycles do not displace water. Hydroplaning on a bicycle on concrete or asphalt is not a risk . BTI addressed this in a general article and in a 1997 article by Jobst Brandt, “Tires with Smooth Tread. A writer at CyclingTips addressed treads in 2014 in Rubber side down: the function of road tyre tread patterns:

A road tyre is already very effective at displacing the water thanks to its round profile so Jobst Brandt has argued that a patterned tread is unnecessary. A broader survey of current thinking amongst tyre manufacturers supports this view, though some see room for marginal gains through a tread-pattern design.

Slicks or near slicks have become a popular choices for “road” bikes. Some favour a file tread pattern (thin shallow closely spaced ribs at an angle to the path of travel; like the cutting edge of a file – the tool). Jan Heine, the editor of Bicycle Quarterly, and principal of René Herse Cycles addressed this:

… we are examining myths in cycling – things that we (and most others) used to believe, but which we have found to be not true. Today, let’s look at tire tread: Tread patterns matter – they can make a difference – even on the road. “Bicycles don’t hydroplane,” declared some experts many years ago. “Hence, tire tread patterns don’t matter on the road.” The first part is true – even wide bicycle tires are too narrow to lose traction due to hydroplaning – but tire tread doesn’t only serve to evacuate water from the tire/road interface.

In fact, the tread of bicycle tires has other purposes. I once cycled on the polished stone that surrounded a college library, and I was surprised by the lack of grip: I crashed. Even though I was unhurt, I learned the hard way that the coefficient of friction between our tires and the rocks that make up the road surface isn’t very high. Yet we don’t crash on roads made from the same rocks, but in the form of rougher aggregate in pavement. What happens is that tire and road interlock to create grip.

If our grip came only from pure friction, the size of the contact patch wouldn’t matter. Physics tells us that if you double a tire’s width, it will be pushed into the road surface with half as much force – the two cancel each other. Yet race cars run ultra-wide tires because they provide more grip. What is going on?

Tires interlock with the road surface. Imagine each little surface irregularity like a spike that pushes into the tire. The wider the tire, the more surface irregularities it touches; hence it has more grip. A softer tire also has more grip because the road surfaces pushes deeper into the tire. That is why the tires of race cars use very soft rubber, and why wider bicycle tires at lower pressures offer more grip than narrow ‘racing’ rubber at higher pressures.

There is another way to increase the interlocking between tire and road: provide edges on the tire that ‘hook up’ with the road surface irregularities. Each edge provides a point where a road irregularity can hook up. The more edges you have, the better the tire hooks up.

Jan Heine, February 22, 2018 (updated 2020) René Herse Cycle Journal, Myth Debunked: Tread Patterns Matter, even on the Road

Contact Patch, Deflection, Tire Drop, Rolling Resistance

The weight of the bicycle rests on the contact patches of the tires, the area where each tire deforms from the circular shape of the tire in cross section to the (flat) shape of the surface as the bike rolls forward.

… the role of air pressure in the tire is to hold the fabric under tension — in all but one place, the contact patch with the road surface.

Air pressure can’t add tension at the contact patch, because the contact patch is flattened against the road. Air pressure can only push directly outward, and so here, it pushes directly downward. The downward force of the air must equal the weight load, and so the area of the contact patch approximately equals the weight load divided by the air pressure. (Edge effects and skewing of the weave of the fabric may result in some difference.) For example, if the air pressure is 50 PSI and the load is 100 pounds, the contact patch will be about two square inches.

The threads of the tire fabric can transmit loads only lengthwise and in tension. How then, do they transfer the load from the contact patch to the rim?

Because the contact patch is flat against the road, the curvature of the sidewalls next to it is increased, decreasing their tension, and the angle at which they approach the contact patch becomes shallower. These effects produce the bulge seen at the bottom of a tire under load and transfer the load from the contact patch to the tire sidewalls. The threads of the fabric are pulling downward less and outward more. The load is similarly transferred from the sidewalls to the rim. The sideways forces at the right and left side of the tire are equal and opposite, and cancel out.

Sheldon Brown, John Allen, Bicycle Technical Information, Bicycle Tires and Tubes (see How a Tire Supports its Load)

The rubber at the contact patch bends and rebounds like a spring. The rubber is under tension. The air everywhere in the tire is under pressure but the the tire bulges at the contact patch. The tension of the tire supports the bike.

Because the contact patch is flat against the road, the curvature of the sidewalls next to it is increased, decreasing their tension, and the angle at which they approach the contact patch becomes shallower. These effects produce the bulge seen at the bottom of a tire under load and transfer the load from the contact patch to the tire sidewalls. The threads of the fabric are pulling downward less and outward more. The load is similarly transferred from the sidewalls to the rim. The sideways forces at the right and left side of the tire are equal and opposite, and cancel out.

….

A tire, then, supports its load by reduction of downward pull, very much the same way that spoking of the wheel supports its load. The tension-spoked wheel and the pneumatic tire are two examples of what are called preloaded tensile structures, brilliant, counterintuitive designs working together remarkably to support as much as 100 times their own weight.

Brown and Allen, Bicycle Technical Information, “How a Tire Supports its Load“

The rolling resistance of a tire is an example of elastic hysteresis. The deformity also causes the steering tire to experience pneumatic trail.

Frank Berto (deceased December 2019) was the technical editor of Bicycling magazine, before it became a travel and lifestyle publication. He wrote a book on derailleurs, The Dancing Chain – the 2016 5th edition is still on the market. Frank Berto wrote notable articles on “tire drop” – the change in the height of tire when it bulges under load. Some appeared in Bicycling and other print publication, but were not digitized. He rewrote and updated an article called All About Tire Inflation in 2006. Berto wrote or contributed to an article for Jan Heine’s Bicycles Quarterly published in Issue 19 (V. 5, No. 3, Spring 2007). Steve Vigneau has a pdf copy of “All about Tire Inflation” at his site: https://nuxx.net/files/bicycle/various/Frank_Berto-All_About_Tire_Inflation.pdf. Perhaps other copies and other articles can be located on the Web. Frank Berto explained why road bike tires should be inflated to endure tires stayed on the rim under the forces of cornering, and to avoid “pinching” and deflating an inner tube. For road bikes on pavement, he suggested the pressure should be high enough that tire drop was about 15%. He thought that road riders were overinflating their tires. He thought that mountain bike rides should ride softer, but needed guidance to know the minimum pressure to avoid damage to tires and rims.

Frank Berto largely agreed that road bike tire pressures could be lower than the manufacturers’ marked safety warning. He thought that bike tires need pressure to support the bike and rider and to handle properly. He suggested that the pressure should be enough to keep tire drop around 15% for the bike, rider and load. Tire drop is hard to measure. Like rolling resistance and durability, it is dependent on pressure and the thickness and composition of the tire casing

The deformity causes rolling resistance:

“Rolling resistance” is the mechanical friction generated as the tire rolls. As a segment of the tire tread rolls into contact with the road, it deforms from its normal curved shape into a flat shape against the road, then back to the curve as the tire rolls onward. The deformation of the rubber in this process is what causes the friction. A bias-ply tire has some additional friction because of the “Chinese finger puzzle” effect of the bias plies. The edges of the contact patch scrub against the road as a segment of the tread becomes shorter and wider where it flattens out, then longer and narrower as it becomes round again.

Brown and Allen, Bicycle Technical Information, Bicycle Tires and Tubes: Rolling Resistance

Wider, Softer, Supple

Road Bikes

Manufacturers and consumers used wider tires for some bikes and some kinds of riding for a long time. Mountain bikes had and have wider tires. Gravel bikes have wider tires. Cyclo-cross bikes have wider tires than road bikes. Wider tires hold larger volumes of air at lower pressure than narrower tires:

Tire width and pressure are inextricably linked. It is a serious mistake to consider one independently of the other. Generally, wider tires call for lower pressures, narrower tires call for higher pressures.

Consider, for example, a tire one inch across, at a pressure of 100 PSI (pounds per square inch). Air is pushing down against the bottom half of the tyre cross-section with a force of 100 pounds per inch of length. Each sidewall of the tire bears half that load, and so each inch of length of tire sidewall will be under a tension of 50 pounds. Now let’s consider a tire twice as wide, two inches across, at the same 100 PSI. Each inch of sidewall will be under a tension of 100 pounds. So, a wider a tire would ride harder, and need stronger fabric, if inflated to the same pressure,

The part of the tire that is actually touching the ground at any moment is called the “contact patch.” Generally, the area of the contact patch will be directly proportional to the weight load on the tire, and inversely proportional to the inflation pressure. For instance, if the rear tire of a bike is supporting a load of 100 pounds, and the tire is inflated to 100 PSI (pounds per square inch) the contact area of the tire will be roughly one square inch. If the pressure is reduced to 50 PSI, the tire will squish out until the contact patch has become 2 square inches (or until the rim bottoms out against the tire.)

A common debate among cyclists centers on the issue of whether a wider tire has more or less rolling resistance at the same pressure. The constant pressure is proposed because it appears more scientific to eliminate this as a variable, but this is not realistic in practice. The short answer to this question is that, yes, a wider tire of similar construction will have lower rolling resistance than a narrower one at the same pressure. This fact is, however, of no practical value. If you are comparing two tires of similar construction, with the same load, and the same pressure, either the wider tire is overinflated, or the narrower tire is underinflated!

A tire is supposed to deflect a bit under load. This deflection [is] the whole purpose of pneumatic tires. When you sit on your bike, your tires should visibly bulge out at least a bit under your weight. If they don’t, they’re overinflated.

Brown and Allen, Bicycle Technical Information, Bicycle Tires and Tubes: Width

Stiffness can come from thicker casing and rubber. Tire designers can make tires “supple” by making them with thinner casings and thinner rubber layers on the sidewalls and treads. A supple tire stetches and rebounds rapidly with little loss of energy. It rolls with little rolling resistance, and suspends the bike.

Supple tires have drawbacks:

There are four ways to reduce [rolling resistance], each subject to trade-offs:

[1.] The thinner and softer the rubber/fabric of the tire are, the more flexible they become. The trade-off with this is that the thinner the tire gets, the more fragile it is, and the sooner it will wear out.

….

Brown and Allen, Bicycle Technical Information, Bicycle Tires and Tubes: Rolling Resistance

If the casing and tread are thin, the tire is fragile. The entire contact line of a supple slick tire is exposed to contact with and penetration by small sharp debris. The tread and sidewalls can be gashed by impacts with sharp or pointed edges including broken glass, metal objects etc. on paved roads., and rocks, thorns on gravel and trails.

A patterned tread of hard rubber provided reasonable protection against punctures from small debris, although a pattern leaves an area of the tread with less rubber. The industry addesses puncture resistance with thicker or stronger tire casings and with protection belts. See Cycling Weekly’s Best puncture-proof tyres for cycling 2022.

Knobs & Cleats

Bike, wheel and tire manufacturers designed mountain bikes and gravel bikes with wider tires than road (and cyclo-cross) tires. Tires, with raised tread features – i.e, knobs, ridges or cleats were and are common on mountain bikes. Hybrid mountain bike tires are wider than “traditional” narrow road bike tires but narrower than mountain bike tires. Hybrid mountain bike tires, commuter bike tires and utility bike tires tend to have flat, patterned treads. Generally, gravel tires have knobs.

According to Jan Heine of René Herse Cycles, knobs and other tread patterns do not increase traction on loose aggregate surface materials (gravel). The tires ride on the aggregate material on the top.. The top aggregates slide or tumble on the lower loose material. Knobs do not increase grip on such a surface. Knobs can grip irregular firm surfaces and surfaces covered by thin layers of loose materials.

Some knobby tires can “squirm”:

Knobby treads actually give worse traction on hard surfaces! This is because the knobs can bend under side loads, while a smooth tread cannot. The bending of knobs can cause discontinuities in handling: the tire grips OK for mild cornering, but as cornering force exceeds some critical value, the knobs start to bend and the traction suddenly goes to Hell in a handbasket.

Brown and Allen, Bicycle Technical Information, Bicycle Tires and Tubes: Squirm

It depends on the size and shape of the knobs, the tread material, and the way the tire deforms and contacts the road. The tire streches and deforms around around knobs when the knobs are under the contact patch.

Thick knobs are less vulnerable to puncture than the thinner parts of the tread when the knobs are in the contact patch. The risk of puncture depends on the shape and size of the debris, the angle of impact, speed, and weight. I can’t find any discussion of the role of knobs in protecting the tire from puncture by small debris.

The knobby mountain bike tires made in the 1980s and ’90s were noisy. Tires with knobby tread were also generally thicker and stiffer. Knobby treaded tires were slower because the tires were stiff and slow. I switched from knobby tires to a patterned tread tires on my Giant hardtail mountain bike, and rode patterned tread tires on my hybrids and my old road bike for years. I was quieter and I thought I was faster. I don’t really know.

Manufacturers have modified tread patterns with knobs and cleats to reduce noise. Modern raised tread patterns are more likely to hum rather than buzz or roar, but can still be noisy.

Valves, Chucks, Gauges

The Schader valve used on automobile tires was used on bicycles in North America. Presta valves were once found mainly on the narrow tires and tubes of road bikes. Presta valves have become common on gravel bikes. mountain bikes and hybrid bikes. Bicycle Technical Information lists Schrader, Presta and Dunlop and illustrates these valves. Wikipedia’s valve stem entry has a 4th type.

A valve stem is a self-contained valve. Cyclists refer to the exterior shell, which is often threaded, as the stem. Some small bike pumps can be attached to the stem. Most pumps attach to the stem with a hose fiting on the pump hose called a chuck.

The Schrader valve allowed cyclists to use air pumps at automobile service stations. The pumps had chucks to fit on Schrader valves, and worked on Presta valves if the user had an adapter. These pumps were useful for cyclists if a service station was near (before service stations began to put coin meters on air pumps) if the user could limit or control the volume and pressure. Some industrial pumps could blow out a bike tire, delivering large volumes at high pressure.

In the 1950s and 60s young cyclists learned to test pressure by grasping the wheel rim and pressing the tread to see if the tire would deform under that pressure. It was not a measurement and it depended on strength and effort. Modern riders have access to analog and digital gauges to test pressure, cycling computers to record speed, location and elevation and power meters.

Pressure – Warnings, Manufacturer Recommendations

Many riders expect the manufacturer to specificy an optimal recommended operating pressure. The value stamped or marked by the manufacturer on the sidewall is not the an optimal value or the optimal value:

Most tires have a “maximum” pressure, or a recommended pressure range marked on the side of the tire. These pressure ratings are established by the tire manufacturers after consultation with the legal and marketing departments. The lawyers want the number kept conservatively low, in case the tire gets mounted on a defective or otherwise loose-fitting rim. They commonly shoot for half of the real blow-off pressure. The marketing department wants the number high, because many tire purchasers make the (unreliable) assumption that the higher the pressure rating, the better the quality of the tire. Newbies often take these arbitrary ratings as if they had some scientific basis. While you’ll rarely get in trouble with this rote approach, you will usually not be getting the best possible performance. … Optimal pressure for any given tire will depend on the load it is being asked to support. Thus, a heavier rider needs a higher pressure than a lighter rider, for identical tires.

….

Rough surfaces generally call for a reduction in pressure to improve ride comfort and traction, but there is a risk of pinch flats if you go too far. Even at the lower appropriate pressure, wider tires, because they also are deeper, are more immune to pinch flats.

Brown and Allen, Bicycle Technical Information, “Pressure & Pressure Recommendations“

Industry Testing

Testing of tires for automobiles and aircraft (landing gear) for safety was established by governments, regulatory agencies and regulatory bodies. The performance of materials and components in the various situations became a testing point, and testing would have been necessary to sell those products.

Bicycles have been athletic, recreational and entertainment products, and a means of transportation, and even toys. Tire testing, unless required by consumer protection law or the rules of competition, was unusual. The test data for bicycle tires, if any, may be found in the papers of the inventors and manufacturers.

Josh Poertner, the principal of Silca Velo suggested (to Tom Anhalt in an interview (link below), that manufacturers of bicyle tires had no data about tire operation or performance because they were not testing, and that no one knew how to test bicycle tire performance until the early decades of the 21st century. Poertner said that manufacturers relied on their own reputations and industry practice when they made claims that tires were “fast”, efficient, grippy, puncture-resistant, comfortable etc. In a few of the earliest Silca Velo podcasts Josh Poertner discussed tires and inteviewed engineers who had started bicycle tire performance testing:

• Hysteresis
  • Podcast November 4, 2019- Hysteresis in Marginal Gains;
  • YouTube Video (February 26, 2020);
• November 19, 2019, Podcast – A Conversation with Robert Chung;
• July 9, 2020 Podcast – Tire Pressure Pioneer: Tom Anhalt.

Cyclists started to demand, unsuccessfully, that when manufacturers claim that competive road casing tires are efficient or fast, they should disclose data. Manufacturers can feasibly test protypes and production samples on testing devices that put pressure on tires as tires are rotated against rollers and drums. Manufacturers prefer to rely on brand reputation and price to persuade riders that a tire is fast, light or high quality.

It is not likely that manufacturers will ever voluntarily disclose research on materials and products under development.

Consumer-led testing

For several decades, from the 1960s, riders, mechanics, bike shops and tire manufacturers shared a common belief and maintained that road bike tires should be narrow and inflated to high pressures. Several sectors of the cycling industry were vested in narrow tires by the 1990s. Road bike frame and fork designs accomodated narrow tires. Wheel manufacturers manufactured wheel rims for narrow tires. Tire manufacturers made narrow tires and tubes.

Cycling magazines seldom pay journalists to test products or challenge the practices of manufacturers who pay magazines to advertise products and publicize cycling. There was some industry reseach on rolling resistance in bicycle tires, but the methods and results are obscure. In an article on the triathlon site Slowtwitch.com:

I’ve heard, though I haven’t seen, reports of rolling resistance studies Continental performed that included an analysis of tire width. … it seems intuitive to me, that there is not much if any measurable difference in the rolling resistance of a 20mm tire versus a 24mm tire, all other things equal. Thinner tires require more attention, though, in that they’re more susceptible to increased rolling resistance if they’re not inflated to a sufficient pressure.

….

After you’ve satisfied yourself (or if you’re willing to take my word for it) that a 23mm or 24mm tire will roll as efficiently as a 9mm or 20mm tire, you can move to the next two issues, which are aerodynamics and resistance to flats.

Dan Empfield, Slowtwitch.com, September 2002, Rolling Resistance

Cycling computers and tire pressure gauges allow riders to check their real speed, tire pressure and other parameters. This allowed riders to compare tires and tire pressures.

Independent researchers including Robert Chung, Al Morrison, Tom Anhalt and Jan Heine started research into road bike tires at or after the end of the 20th century. They recorded data with gauges, cycling computers and power meters available to them. They communicated with each other, sometimes, on Usenet or in other internet services, or by telephone.

Tom Anhalt’s equations to convert Crr (Coefficient of rolling resistance) on rollers to flat surface were written in 2006 (published in 2013 on his blog Blather ’bout Bikes) Tire Crr testing on Rollers – The Math. His charts comparing narrow triathlon road racing tires were published in 2013 on his blog Blather ’bout Bikes, Tire Crr Testing on Rollers – The Chart … and a “how to”. Tom Anhalt’s 2009 article on inner tubes formulated the theory of the breakpoint, at which increasing tire pressure increases rolling resistance:

When thinking about tire pressure and what is “fast”, it helps to think of it in terms of a “resistance to forward motion” rather than just thinking about the rolling resistance of the tire itself. As we’ve seen above, increasing pressure inside the tire decreases the rolling resistance of the tire itself, and this fact has been observed in tests of rolling resistance vs. tire pressure on smooth rollers. With increasing pressure, the rolling resistance drops at a decreasing rate until at very high pressures it’s basically a flat line. So, does that mean that increasing pressure in a tire lowers the rolling resistance of the tire on a rougher surface as well? The answer is: “Yes…but..” The rolling resistance of the tire continues to decrease with increasing pressure on rough surfaces as well, BUT at some point the increasing pressure stiffens the “air spring” so much that the increase in transmitted energy loss overwhelms the decreasing rolling resistance of the tire, with the result being that the actual ” resistance to forward motion” starts increasing. The net result is that above a certain pressure (what I like to call the “breakpoint pressure”) higher inflation pressures make a rider slower for a given power input to the pedals. Adjacent is a simplified schematic representation of this effect. Very little data is commonly available that shows this effect. Mainly out of curiosity about whether or not this effect was measurable, and to what the magnitude of the effect was, this author undertook an experiment “on the road” armed with a PowerTap power meter and a method for determining the Crr (coefficient of rolling resistance – actually, in this case the “resistance to forward motion” proportional to velocity) illustrated here.

Tom Anhalt, Slowtwitch.com. September 21, 2009, What’s in a Tube

Robert Chung developed a power equation that considered Cda (drag area) as well as Crr. He wrote a paper “estimating CdA with a power meter” which has been distributed on the internet. Tom Anhalt discussed the March 2012 version of the paper in his Blather ’bout Bikes post August 4, 2013 “Aero Field Testing using the “Chung Method” – How sensitive can it be?“.

Lower pressure was an innovation when applied to road bicycle tires. Some professional road racing teams or their consultants began to experiment. Some experimenters tried to protect their data and insights to maintain advantages for racing teams, consultants, and tire manufacturers. Academics publish. Manufacturers and consultants hoard trade secrets.

Josh Poertner, before acquiring the Italian Silca Velo brand, had worked on wheels and tires as a manager in Zipp’s Speed Weaponry division, advising professional road racing teams. He was familiar with the literature, and was involved in testing. Josh Poertner/Silca Velo started to podcast or make videos in 2019. Josh Poertner sometimes suggests that the modern engineering of Anhalt has superceded the views of Frank Berto. Anhalt relied on some of Berto’s work in a post on gravel tires February 16, 2020 and his graphs on rolling resistance and pressure. The reasoning and the math is complicated. It seems that Anhalt did not overthrow Berto’s work.

Bicycle Quarterly

Bicycle Quarterly (“BQ”), is a printed publication founded by Jan Heine, the principal of Compass Cycling and René Herse Cycle of Seattle, Washington, USA. BQ was first published in 2002 as a publication about “vintage” bikes. Jan Heine favours drop bar bikes without mechanical/hyrdraulic suspensions: road bikes, endurance road bikes, and “all-road” bikes. His favoured off-road forms of riding include cyclo-cross. He rode Unbound Gravel in Kansas in 2022 on a vintage design René Herse 12 speed (2 x 6) all-road bike. He reviews bikes built by custom builders – frequently bikes built with steel frames. BQ has discussed the uses of bicycles on gravel roads, and self-supported distance riding (randonneuring). René Herse Cycles has a YouTube channel. Some of the videos are about rides in the Cascades and other parts of the US Northwest. Some illustrate bike design, handling, and maintenance:

• Myths Debunked: Trail Makes a Bike Stable
• Removing Tires Without Tools

Most of Jan Heine’s books were independently published by Bicycle Quarterly Publications and sold by René Herse Cycles, and by Amazon:

• The Competition Bicycle (2008, reprinted 2012),
• The Golden Age of Handbuilt Bicycles: Craftsmanship, Elegance, and Function (2009),
• René Herse: The Bikes • The Builder • The Riders (2012),
• The All-Road Bike Revolution (2020).

Several of Jan Heine’s books explore history and document the quality of 20th century bicycles. The 2020 book is a short manual for purchasers and riders, and discusses features of modern bikes. Jan Heine frequently observes that modern bikes originated in bicycle designs in the early and middle parts of the 20th century. He respects innovation, but has raised questions about innovations that fail to improve the owner/rider’s experience. He points out that a steel bike from a home builder or small manufacturer can be a better bike, and less expensive than most bikes produced by modern factories.

BQ discussed tire pressure, tire testing and tire design many times. Jan Heine and other riders and writers associated with BQ began testing and writing about rolling resistance and tire tests in BQ issue 17 (aka Volume 5, No. 1, Autumn 2006). Heine respects Frank Berto’s efforts to measure tire drop – he relied on it in developing the René Herse online pressure calculator tool, which became active in the spring of 2022, and cites Berto in journal entries such as “Tire Pressure Take Home” (March 2016).

BQ writers criticized the lack of testing by tire manufacturers, and the use of machines that tested tires on steel rollers or drums. They preferred to test tires by comparing performance on the same surface, without pedalling, by letting bikes roll down measured distances, downhill under low wind conditions – the “roll-down” test. It is a low-tech process that requires time, and measurements of distance, time, and speed. Jan Heine designed tires, manufactured (according to some sources by Panaracer) for Compass and René Herse in Japan, and brought the tires to market. He can be seen as :

• a fan of vintage bikes and
• promoting his brand of supple tires, and
• questioning some of the practices of bike and tire manufacturers.

Jan Heine maintains that hard narrow tires cause the bike to vibrate, even on smooth pavement, which riders perceive as an indication the bike is fast. He summarizes his reseach as supporting the view that an overinflated (hard) tire transmits vibration which slows a rider down – a hard tire is not an effective shock absorber. Jan Heine expressed his views to the readers of the Adventure Cyclist magazine of the Adventure Cycling Association in March 2009 in the article “PSI Rx“. The article discussed the way tires lose energy the rider put out to get the bike rolling forward:

Suspension losses – a bike that vibrates and bounces from one bump to the next is lifted up time and again. Lifting the bike requires energy. Part of this energy is absorbed inthe rider’s body and, on a touring bike, by the luggage. The rest is returned as the bike rolls off the bump. When you accidentally ride into the rumble stripsthat separate many U.S. highways from the shoulder … you also slow down immediately as energy is absorbed in your body. By smoothing out the bumps, pneumatic tires save energy.

Deformation losses – the downside of a soft and squishy tire is the deformation of the tire as the wheel rotates. Most of the energy necessary to bend the tire casing is returned as it springs back into shape at the rear of the contact patch, but some of it is lost to friction within the tire and is no longer available to drive the bicycle forward.

For the best performance and comfort, you need a tire that is neither too hard nor too soft. Instead of inflating your tires to the maximum pressure, run them at the optimal pressure, where they deflect enough to keep the bike from vibrating too much yet are not so soft that they slow down due to excessive deformation losses.

Tire drop measures how much the tire deflects under the load of rider and luggage (Figure 1). For example, if your tire is 30 mm tall without a load and 27 mm tall once you sit on the bike, your tire drop is 3 mm or 10 percent.

….

Properly inflated, wider tires provide much more comfort. When you hit a bump and your tire drop increases from 15 to 18 percent, the 23-mm tire will give you only 0.69 mm suspension, whereas the 37-mm tire deflects 1.11 mm. The added suspension of the wider tire makes it faster and more comfortable on rough roads.

But aren’t narrower tires faster? Not really. The key to a fast tire is a supple thin casing that requires less energy to deform than a sturdier thicker casing. For a variety of reasons, many wide tires use heavy-duty casings, which are indeed slow. Wide tires with high-performance casings can be very fast. In Bicycle Quarterly’s tests, the five fastest tires ranged in width from 24 to 37mm. … thin supple casing is faster because it absorbs less energy as it deforms.Thus, it will deform more for a given bump, making it more comfortable than a sturdier tire with a thicker casing (for the same tire width and pressure). The downside of a thin supple casing is reduced resistance to punctures.

Jan Heine, March 2009, Adventure Cyclist, PSI Rx

Jan Heine’s point is that a supple tire deforms and recovers faster, and absorbs road vibration that a stiff tire will not. Jan Heine acknowledges that the thin supple casing has disadvantages and risks, including reduced resistance to punctures. In the printed BQ articles about his attempts in 2021 to record the Fastest Known Time on the Oregon Outback route, he discusses the risks of gashing supple tires on sharp rocks on gravel surfaces.

Jan Heine and Josh Poertner were guests on CyclingTips Weekly Podcast Episode 9, August 21, 2016 “Rethinking road bike tire sizes and pressures“. Elden Nelson, the (former) blogger at Fat Cyclist was the podcast host. (Elden Nelson and Michal Hottner co-host a podcast about the Leadville Colorado mountain bike race, and the Silca Velo Marginal Gains podcast. He stopped blogging in 2022). James Huang, a CyclingTips technical writer, was a guest or co-host. It may be necessary to play the mp3 version – the 2016 episode is not available in the podcast search function in several podcatcher apps. It is over an hour long. Jan Heine and Josh Poertner agreed that lower pressures were faster. The discussion was summarized in an article in/on CyclingTips in 2017 “What is the optimal tyre pressure?“

The amount of energy that is wasted due to suspension losses increases significantly as the surface of the road gets rougher. Jan Heine measured huge losses when riding the rumble strips that border some roads while Josh Poertner found that even a small amount of over-inflation (10psi) could produce an obvious penalty.

….

Much of the data favours wide (25-28c), supple tyres at lower pressures (60-80psi/4-5.5bar), but every rider should feel free to experiment with tyre size and pressure until they are pleased with the performance of the bike.

They agreed that many riders would be better off with wider, softer and more supple tires, and that the optimal tire pressure is usually below the manufacturer’s safety warning. Each had reasons, and relied on particular data points. Poertner cited “supple” practices of professional road racing teams such as the use of latex inner tubes (as opposed to the more common butyl rubber tubes) and the use of thin casing supple tires in races. Poertner agreed that that overpressure beyond the breakpoint (see Tom Anhalt, above) can produce a penalty. They had some differences, but they did not discuss or debate them. The article in/on CyclingTips is imprecise on some points. As the breakpoint is dependent on weight and sensitive to surface, a rider may have to monitor pressure, use data based calculator programs, and test. Rolling resistance cannot be stated for a tire, without knowing other parameters.

The Consultant’s View

Josh Poertner is an engineer and entrepeneur:

• He views reducing tire pressure as a way of reducing rolling resistance as a marginal gain for competitive riders;
• He favours the idea that new ideas, methods and products are generally better;
• He is aware of the costs and constraints affecting the way tires are made – the cost of material, the costs of machines, transportation, energy and labour;
• He is aware of the way engineers in the automobile-related industries have addressed the constraints;
• He is responsive to the financial constraints of industry.

Like the Ferengi on Star Trek, manufacturers focused on the acquisition of profit as the highest goal can resist making performance the highest standard – it a customer wants high performance, like a professional cycling team manager, the customer needs lots of money.

By 2016, according to Josh Poertner, several road racing teams were using slightly wider tires, and pumping the tires to pressures determined by their procedures for the weight of the rider and bike, and road conditions. Poertner referried to chip seal and gravel as rough. Poertner says he is impressed by Chung, Anhalt and others who have worked with mathematical formulas and gather data with specific tools. Poertner accepts testing on rollers and rotating drums.

This kind of testing involves some machinery. When testing became feasible enough for riders to tinker and test, it also became more feasible for manufacturers and industry stakeholders to test. Testing on machines can be standardized and scaled – and is less costly for manufacturers:

It is relatively straightforward to measure rolling resistance under controlled conditions. A large rotating drum or a set of rollers can be used to reproducibly identify relatively minor differences in rolling resistance allowing different brands, models and sizes to be compared and ranked to identify the “fastest” tyres. The influence of other variables — including tyre pressure, different inner tube materials, and for tubular tyres, the method of gluing — has also been tested.

….

It was Tom Anhalt that first raised the possibility that there was more to rolling resistance than friction alone. By comparing his “lab” data with real-world data, Anhalt noticed an unexpected increase in rolling resistance when high tyre pressures were used on the road. Jan Heine and Josh Poertner subsequently confirmed these observations, ushering in a fresh view on rolling resistance and renewed appreciation for lower tyre pressures.

CyclingTips, May 2017, “What is the optimal tyre pressure?“

Poertner says he thinks roll-down testing is very limited. He appears to view Frank Berto’s work as out of date. Poertner is focussed on the marginal gains of improving aerodynamic performance. Poertner’s views are influencing cycling influeners – e.g. Lennard Zinn:

… if there is a question about whether a fatter tire is faster than a skinnier one on a rough road, where the bigger tire should have the advantage, then on a smooth road, the narrower tire will likely come out ahead. And even if there is little or no difference in rolling resistance, the advantage will go to the narrower tire overall, due to its lighter weight and lower aerodynamic drag. Contrary to that René Herse blog you sent me, bigger tires are slower aerodynamically, except when the rim is wider than the tire.

As for the René Herse tire rolling-resistance results … This is the methodology the author (Jan Heine) employed for those René Herse tire tests. I respect the enormous amount of work, time and effort that went into those tests. On the other hand, you can’t accurately quantify a small friction difference between tires, tire widths, or tire pressures when the main thing you’re actually measuring, namely aerodynamic drag, dwarfs those tiny differences.

…..

I’m still left with the fact that the main thing determining the riders’ speeds was wind resistance, since rolling resistance is so much smaller of an effect. That’s why, if we really wanted to be able to quantify what tire pressure, width, or model was faster than another, we needed to do it in a lab, and it couldn’t be just any lab, as I explain[ed][November 23, 2021, Technical FAQ]

Lennard Zinn, VeloNews, December 14, 2021, “Technical FAQ: Tire Rolling Resistance testing methodology“

“Unfortunately, the only way we can truly know the tire pressure breakpoint for a particular rider on a particular surface is to conduct virtual elevation testing (Chung Method testing), which is a methodology whereby we can use real-world data sets to back-out rider CdA and Crr to very high degrees of accuracy. Having done hundreds of these tests, what we find is that the ‘fastest tire’ in the field is the same one we find on the smooth or rough drum in the lab, but the breakpoint pressure depends greatly on rider size/weight/body composition, as that is what is ultimately driving the whole spring/mass/damper side of the equation.

“If you wanted to test that with a machine, you’d have to do some sort of shake rig testing (as we do with racecars) to determine the spring/mass/damping relationship at each tire contact patch and then model that into your bump drum to simulate that spring/mass/damper on top of the tire. Again, the fastest tire will still be the fastest tire, but you could then accurately predict breakpoint!

“This is what makes our tire pressure calculator so unique; it is a curve fit of thousands of real-world virtual elevation data points taken with pro athletes over a 6+ year period. No, the challenge with this data set is that the selection of tires used is extremely top tier. So, the breakpoint is likely a bit high for those running less extravagant tires, and secondly, our athletes are the fittest in the world, so the breakpoint is likely higher than for the average consumer, as these data were produced with athletes all having very low body fat percentage and therefore, lower hysteresis than most normal people!

….

” … roll-down testing, as you know, is a terrible tool for looking at Crr, and I would go as far as saying that it really just can’t/doesn’t work unless you are trying to parse very good from very bad tires.”

— Josh Poertner, Silca president

” … misinterpretation of smooth drum tests has led to misleading conclusions, and really mostly about pressures. Smooth roller tests on tires of equivalent construction, but varying widths, shows that at equivalent pressures, wider tires test faster on the smooth drums, and, with “appropriate” pressures in each, are basically equivalent. Yes, smooth roller tests, or rough roller tests without damping, don’t properly demonstrate breakpoint pressures. Now that this is understood, it’s also important to remember that below breakpoint pressures, roller testing is a very valuable tool for evaluating tire hysteresis losses.”

— Tom Anhalt

Lennard Zinn, VeloNews, January 4, 2022, “Technical FAQ: Tire Rolling Resistance testing methodology and verification“

Lennard Zinn did not explore or explain Tom Andhalt’s comment on the limitations on drum/roller tests at breakpoint pressure.

Poertner assisted journalists at the Hearst publication Bicycling with an article in the spring 2022 issue (Volume 63, No. 4 at p. 65-66, if one has access to this paywalled magazine. I had access through a public library access licence). A test rider was timed and power output was recorded riding a bike equipped with Pirelli P Zero Race TLR tires in three widths – 26, 28 and 30 mm. Each tire width was at three pressure combinations (F/R psi: 90/95, 70/75, 50/55) over two 2.5 mile courses – a smooth and flat (paved) bike path, and a rolling road with “mostly good quality pavement”. Poertner is cited for explaining Tom Anhalt’s breakpoint math, as saying that wider tires are not necessarily faster, and as a supporting the writer’s interpretation of the test results:

“There is the conventional wisdom that wider tires have lower rolling resistance, and if you took a given tire construction and just scaled it, you would probably find that to be true. But in the real world, because of the way tire makers make their tires, that is not always true. I know this can be hard to hear … but it really just depends.”

….

Its not surprising that a 30 mm tire pumped up to 90/95 was the fastest on … smooth flat road. At [20 mph] rolling resistance is not getting overwhelmed by the aerodynamic penalty of the larger tire.

….

The biggest variable that affects your ideal tire pressure (in terms of speed) will be the surface on which you ride.

Bike and tire manufacturers prefer to test on rollers and drums, and deprecate roll-down tests. there are no standards for the tests or the use of tests in manufacturing and marketing.

In road racing, slightly wider tires and lower pressures have become popular, but the adoption of wider tires in competitive road cycling has been limited. The use of wider tires affects frame design. Bicycle manufacturers are competing to produce lighter and faster bikes. Bike manufacturers are replacing metal with plastic composite. At present, carbon fiber is an expensive single-use plastic. Some bike companies greenwash their use of carbon fiber composite as dematerialization. This uses carbon fuels – the energy costs are significant. The road racing interests have tried to get aerobic gains by reshaping bikes and components and changing cycling apparel.

My Tires

My bike in the last half of 2019, 2020, 2021 and 2022 was a 2019 model Cannondale Topstone with WTB tubeless ready wheels to fit 700c tires on a 23 mm. (inner bead diameter) rim. I ran the wheels and tires as clinchers with normal basic butyl rubber inner tubes. The WTB Nano tires had knobs, shown in the photo below. The main tread shows as dusty grey; the raised knobs are black. The larger 4 sided knobs were about 4 mm. front to back x 5.7 mm. The thin knobs on the center line were 14.4 mm. fron to back x 3.75 mm. across, and spaced 5.1 mm. apart. An image of the tread pattern of knobs, arranged in chevrons pointing in the path of travel, seen from the front, is below. These were fairly small knobs, and pretty typical of the tread pattern of modern tires. They were quiet – nearly silent. WTB marked the range of inflation from minimum 35 psi/2.4 bars/240 K.Pa to maximum 55 psi/3.8 bars/380 K.Pa.

Those tires, at 700c x 40 mm., were slightly too big to allow me to put fenders on that bike.

I replaced the WTB Nanos with 700c x 38 mm Panaracer Gravel King SK tires. The actual diameter of this tire (distance from the widest point between the sidewalls) on the 23 mm. rim was about 41.5 mm. The tires were marked with tubed maximum pressure 75 psi/5.3 bars/ 525 kpa, tubeless max 60 psi/ 4.0 bars/ 400 K.Pa

These had, as shown in the image below, 3 rows of 3.5 mm. x. 3.5 mm. square knobs (2.5 or 3 mm high) on the center of the tread, 9 knobs per square centimeters, in a waffle pattern, and some slightly larger knobs on the shoulder between the centre of the tread line and the sidewalls (SK stands for small knob). The small knobs on the center line have the center line thick tread on the contact patch, and some grip on pavement. The knobs were soft enough to give with side pressure.

Tom Anhalt included Panaracer GravelKing (SK) at 32 mm. in his post on gravel tires February 16, 2020.

The Panaracer GravelKing (SK) tires rode smoothly, but seemed to me to squirm on worn asphalt, where bitumen showed on the road surface (Wallace Road, in Central Saanich).

From spring 2021 to May 2022, I rode René Herse Barlow Pass 700c x 38 mm. René Herse has this tire in its “all-road”road line of tires. It is basically a road tire. At 38 mm. itis wider than normal for road bikes. The tread pattern is a faint rib to indicate wear, with a fine file tread on the shoulder. René Herse describes/promotes the tires:

For paved roads and smooth gravel, our all-road tread with its fine ribs is the best choice. It combines excellent performance and grip on pavement with surprising traction on loose surfaces – the supple casing allows the tire to grip the surface much better than a stiffer tire.

René Herse advises that the diameter of its Barlow Pass tires should be within .5 mm of 38 mm. The actual diameter of this tire (distance from the widest point between the sidewalls) on the 23 mm. rim was about 41.5 mm with the Extra Light tire and about 42 mm. with the Endurance tire. The height of the inflated tire was about 710 mm. This is little larger than the manufacturer said I could expect. The maximum pressure specified (tubed) is 75 psi/5.2 bars/515 K.Pa.

I picked up some scattered metal debris, which eventually pushed through the tread and casing and caused a number of small punctures of the tube(s). Some caused rapid deflation. Others caused slow leaks. I may have taken some pinch flats. Supple tires are fragile – as many have said.

I installed René Herse Steilacoom 700c x 38 mm. tires in May 2022. This tire was introduced in 2018. It was the first, and at the time the only René Herse (Compass) knobby tire. Tom Anhalt included this tire in his chart of his test and equations of gravel tires in February 2020. René Herse describes this tire as the ultimate cyclocross tire. It has “dual-purpose knobby tread” which René Herse describes this way:

Our dual-purpose knobbies offer supreme traction on dirt, mud and even snow. They are also a great choice for riders who prefer a more aggressive tread on loose surfaces. On pavement, our knobbies will surprise you with their low rolling resistance and excellent cornering grip. They’re the perfect tire for adventures where you don’t know what lies ahead.

The diameter of the tire (distance from the widest point between the sidewalls) was about 38.5 mm., and the height (inclusive of the knobs) is 710 mm. The maximum pressure specified (tubed) is 75 psi/5.2 bars/515 K.Pa. 38 mm. tires can be run at 40 psi, or less, depending on the weight of rider, bike and gear according to online tire calculators including Silca Velo and René Herse .

The knobs are arranged three rows of overlapping alternating knobs (wider models have 5 rows). The knobs overlapping the center line on the 38 mm. tire are 6.8 mm. x. 6.8 mm. Those knobs are engaged steadily, within the contact patch, when the bike is riding straight. The knobs in the outer rows on the shoulders are 7.7 mm. x 7.7 mm. The larger outer knobs closest to the center row line up with every second gap between the knobs on the center line. Some of the outer knobs seem to be in the contact patch and to bear some load in straight line riding. More of the outer knobs will be engaged when the bike is leaned to turn, or rocked.

René Herse has brought out other wider tires with the same knobs. In 2021-22 René Herse has been promoting the tread design by listing the riders who have used René Herse knobby tires in gravel races and endurance events.

These tires work with my fenders. On my first rides on these tires, I thought the tires lived up to claim that dual purpose knobby tiress were as fast as René Herse’s slick 38 mm. road tires. The hummed a bit. They ran smoothly on fresh asphalt pavement, worn pavement, and packed gravel. The knobby tread does not pick up water from a wet pavement. It does pick up bits of gravel and throw them into my fenders, as other tires do.

Pressure Calculators

Generally

Riders can use online calculators to assist in the determination of optimal pressure. These depend on data sets, and several parameters. The calculators are generally in the cloud – on a commercial site. Some require registration. Few remember a user or previous data. All want the user to state/enter weight, wheel diameter, tire width. Getting the weight of rider + bike + load can involve standing on a scale holding the bike, weighing some gear separately, and adding up the weights.

The calculators depend on the rider’s use of a gauge. A rider needs, of course, a pump. Many tire gauges appear to read the nearest bar and the nearest psi. My gauge can read the nearest psi but only reads the nearest .1 bars. Tire gauges, like hoses, have to connect to tire valves. Some air bleeds off. Gauges are vulnerable to wear and tear, and can deliver inconsistent readings.

Some calculators want the use to classify the riding surface. On any given ride, I may encounter a few hundred meters of new pavement, a lot of worn pavement, some chipseal and some gravel. This parameter cannot even be predicted some days. A rider will live with the pressure in the tires, unless the rider want to deflate or pump tires en route.

Silca Velo

The Silca Pro Tire Pressure Calculator is free – it does not charge a fee for registration or use. It no longer asks me to register or log in, but perhaps has tracked me and identified me. It requires 7 parameters – some are drop-down choices. It asks for weight of rider + bike + load, as other calculators do. It asks me to enter, from drop-down menus:

• wheel diameter;
• tire width to the nearest mm. – actual measured width, not manufacturer’s stated width (this is possible with a caliper);
• “Tire type”;
• average speed. The 6 options start at Recreational and include “Pro Tour”;
• Weight distribution – a front/rear % split:
  • Time trial or triathlon 50/50;
  • Road 48/52;
  • Gravel 47/53;
  • Mountain bike 46.5/53.5;
• Surface condition

Surface condition parameter has 10 choices (as of June 2022) from “Track (Indoor wood)” to “Category 4 Gravel”. There is a visual guide. The difference in optimal pressure between smooth pavement and chipseal can be about .4 bars (nearly 6 psi). I use worn pavement or Cat. 1 gravel (not “poor” pavement) as the closest estimatse of local conditions.

This calculator will state calculated optimal pressures to the nearest psi or .05 bar. (1 bar = 14.5 psi. At two decimal places, the bar number also give the pressure in K.Pa; 1 bar = 100 K.Pa). The optimal value for a recreational speed on poor pavement, bad gravel or a dirt trail, is almost a minimum pressure. It is worth checking pressure almost weekly and making time to pump tires up in case they have lost .2 or .3 bars.

René Herse

The René Herse Tire Pressure calculator does not calculatedifferent pressures for front and rear tires. It requires only two parameters: weight and tire width. It provides two optimal settings a “soft” setting and “hard setting”. It is based on Frank Berto’s tests and his theory that tire drop was the best signal or symptom of optimal pressure.

The soft setting is close to the Silca setting for Cat. 1 gravel. The hard setting is close to the Silca setting for tires of the same width, for worn pavement.

Table of Contents

• Endless Post
• 13. Cleaning
  • The Bike
  • Cleaning Products
  • Clamshell Cleaners
  • A Clean Chain
  • Bike & General detergents
• 14. Deep Cleaning
  • The Process
  • Solvent
• 15. Etc.
  • New Products
  • Cleaning a Waxed Chain

Endless Post

This is part 5 of 8 posts organized as a single article. individually published as posts on this blog. In March 2024 I began to reorganize and revise the long article. The sections are numbered for reference here and in the table of contents for each post.

Part/Post & Link	S.	Topics
1. Chain Wear		My discovery of wear Issues
	1	Safety Bicycles — History — Variety — Manufactured Industrially — Bike Brands — Shops or Stores — Mechanics
	2	Bike knowledge sources, Internet
	3	Bike Chains
2. Roller Chain	4	Chain Drive
3. Lubrication	5	Lubrication Theory
	6	Petroleum
4. Lubricants
	7	Fluid Lubricants — Motor Oil — Drip Lubes — Engineered — Wet and Dry marketing — Additives
	8	People and Projects
	9	Lubricant Efficiency Tests
	10	Wear tests – chains & lubricants
	11	Innovation 2022-24
	12	Consumers’ options
5. Cleaning	13	Cleaning
	14	Deep Cleaning with Solvents
	15	New Products
6. Durability	16	Modern Chains
	17	Durable Chain
7. Paraffin	18	Paraffin Wax
	19	Method
	20	Wax-compatible Drip Lubes
8. Learnings for Make Benefit		Assortment of Notes

13. Cleaning

The Bike

The solid surfaces of the bike frame and fork are protected with paint – like an automobile or motorcycle. The painted surfaces can be hosed off or gently scrubbed. Few would use a wire brush, sandpaper or metal scrapers on the bike frame.

When the bike is hosed the joints and the open parts, including the chain, are exposed to dirt, water, and detergents. Many products would not harm the painted finish of bicycle frame and fork. Some may splash or spray into vulnerable areas. Brake rotors may be contaminated by materials used to clean the frame or the chain.

Cleaning Products

Solvents and detergents can be used to clean a chain .

Solvents dilute and wash oils and grease off of surfaces. Water is a solvent, which can dilute oils but is not a good solvent to remove oil from metal surfaces. Most industrial solvents are the product of refining or processing petroleum oils. Some industrial solvents are used clean bicycle chains and components that contain bearings.

Detergents are surfactants or mixtures of surfactants with cleansing properties when in dilute solutions.

Surfactants are chemical compounds that decrease the surface tension or interfacial tension between two liquids, a liquid and a gas, or a liquid and a solid. The word “surfactant” is a blend of surface-active agent, coined c. 1950.
As they consist of a water-repellent and a water-attracting part, they
enable water and oil to mix; they can form foam and facilitate the
detachment of dirt.
Surfactants are among the most widespread and commercially
important chemicals. Private households as well as many industries use them in large quantities as detergents and cleaning agents, but also for example as emulsifiers, wetting agents, foaming agents, antistatic additives, or dispersants.
Surfactants occur naturally in traditional plant-based detergents, e.g. horse chestnuts or soap nuts; they can also be found in the secretions of some caterpillars. Today the most commonly used surfactants, above all anionic linear alkylbenzene sulfates (LAS), are produced from petroleum products. However, surfactants are (again) increasingly produced in whole or in part from renewable biomass, like sugar, fatty alcohol from vegetable oils, by-products of biofuel production, or other biogenic material.

Wikipedia entry, Surfactant

Some detergents may interact harmfully with bicycle chains. Some manufacturers of some chain cleaning products have suggested that some industrial detergents can be a cause of hydrogen embrittlement¹Josh Poertner of Silca Velo suggested this about Simple Green and any detergent that was not certified for use on metal parts in aviation.

Clamshell Cleaners

These are devices that can be attached to the lower span of a chain on a bicycle placed against a support, when the bike is not in motion. The chain is rotated through the device by pedalling backward as the user hold the device steady. The device has rollers with bristles that pentrate inside links and bend the chain into the lower compartment, which is usually filled with a chain detergent. The Park Tool CM-5.3 is one modern device.

These devices remove dirt sticking to the chain by rotating the chain in detergent that facilitates detaching dirt from the metal, and rubbing off the dirt. These devices remove dirt in the chain on the outside surfaces including the surfaces oriented inside such as link plates. This gets close to getting a chain clean enough to lubricate. The bristles and cleaning components of these devices do not reach inside the sleeves, around the pins, or in the spaces where link plates overlap with brushes or friction.

Clamshell devices hold tiny amounts of detergent which gets dirty, which leads a user to believe the chain was dirty – which was a given. These devices have to be emptied and refilled at short intervals. They clean the visible surfaces including most of surfaces of link plates and roller pretty quickly.

The detergent will penetrate the chain. It may take a long time to remove internal contaminants, which will also introduce more detergent and water. They only clean the “insides” of the chain to the extent that detergent gets in and out, and carries away contaminants. It is best to wait and let the detergent dry off before re-lubricating a chain. Wet detergent residue contaminates any new lubricant.

The information security consultant Bruce Schnier uses the term security theatre:

Security theater refers to security measures that make people feel more secure without doing anything to actually improve their security.

Schnier on Security, Beyond Security Theater

A Clean Chain

Chains wear and have to be replaced to protect other drive train
components and ensure the proper operation of the gears. The point of
cleaning, and using using better chains and lubricants is to delay the replacement of the chain and to avoid damaging other components of the drive train.

Most chain cleaning removes visible material that interferes with the chain. Many pages, videos and podcasts discuss cleaning chains; for instance:

• The “How to clean your drivetrain” section in The complete guide to bike gears | Bicycle transmissions explained at BikeRadar

Many chain cleaning articles address:

• removing the visible dirt that sticks to the ouside and inside of link plates, on the chainwheels, in the derailleur pulleys and on or between the cassette cogs;
• cleaning chains that have been lubricated with motor oil, gear oil, and most of the proprietary bicycle chain drip fluid lubes.

It is essential to get the outside surface of a chain clean enough to be able to lubricate it. This is a dirty job

It is difficult to remove the microscopically small particles of grit that adhere to the rollers, link plates, pins and other load bearing surfaces Jobst Brandt, in a paper published in Bicycle Technical Information (Sheldon Brown site), described the problem (emphasis added):

Chain wear is caused almost exclusively by road grit that enters the chain when it is oiled. Grit adheres to the outside of chains in the ugly black stuff that can get on one’s leg, but external grime has little functional effect, being on the outside where it does the chain no harm.

The black stuff is oil colored by steel wear particles, nearly all of which come from pin and sleeve wear, the wear that causes pitch elongation. The rate of wear is dependent primarily on how clean the chain is internally rather than visible external cleanliness that gets the most attention.

Only when a dirty chain is oiled, or has excessive oil on it, can this grit move inside to cause damage. Commercial abrasive grinding paste is made of oil and silicon dioxide (sand) and silicon carbide (sand). You couldn’t do it better if you tried to destroy a chain, than to oil it when dirty.

….

… the chain should be cleaned of grit before oiling, and because this is practically impossible without submerging the chain in solvent (kerosene, commercial solvent, or paint thinner), it must be taken off the bicycle.

Jobst Brandt, Bicycle Technical Information, January 2002, Chain Care, Wear and Skipping; (Also see Jobst Brandt bio and index of Jobst Brandt’s BTI articles.)

The grit in a chain is partly the metal products of friction between steel surfaces, and between chain parts and grit in the lube. The grit includes dust suspended in air or accumulated on the road and suspended in water on the road.

Deep cleaning will be addressed in section 15, below. Deep cleaning of a new, unused chain is the most effective way to remove enough factory grease to let lubricants adhere to bare metal. It is recommended/required as a prelude to lubrication with:

• Immersion waxes by manufacturers of the paraffin wax products and the hot waxing advisers; and
• Modern fluid chain coating wax products by some of the manufacturers – e.g. Silca Super Secret Chain Coating

A deep cleaning may be necessary “to reset contamination” (as Adam Kerin of Zero Friction Cycling refers to this) if the hard wax on a chain had been contaminated by dirt, water and wear under adverse conditions. Deep cleaning can be used with chains that have been run with drip lubes. It can remove most contamination when a chain has been contaminated during a ride(s) under adverse conditions. It is not a common practice.

Deep cleaning involves removing the chain from the bike. Removing a chain required using a chain breaker to remove and installed a pin for chains without master links. Master links need to be replaced, although not necessarily after a single use.

Deep cleaning also involves soaking the chain in a solvent. The effective solvents have been harsh industrial chemicals which may require handling and disposal as hazardous waste. The detergents have to be flushed with water, and the chain has to be be dried!

The limits of deep cleaning were lllustrated by a parody in an April Fools Day (prank/humour) article “The ShelBroCo Bicycle Chain Cleaning System” in the Bicycle Technical Information (Sheldon Brown) pages. A complete cleaning of a chain could literally require dissassembly of links!

Bike & General detergents

Many users use general purpose cleaners. Some use cleaners marketed as bicycle chain cleaners or degreasers. A 2023 post or page The Best and Effective Degreasers in 2023 at the GeekyCyclist site listed products sold in bike shops including:

• Simple Green
• WD-40 Bike Degreaser
• Park Tool Bio Chainbrite
• Muc Off Bio Drivetrain Cleaner
• Pedro’s Oranj Peelz

In Canada, the cycling section of any Mountain Equipment Cooperative store sold the MEC store brand Bio-Cycle Chain Cleaner detergents.

Many bike and general detergents are easier and safer to handle than solvents but once used to remove grease or oil, may be subject to hazardous goods disposal rules for oil and grease.

Some users use a chain cleaner/degreaser detergent product to clean the chain. Some use the cleaner/degreaser with brushes or a clamshell cleaner. Some users used a cleaner/degreaser before removing a chain to deep clean it with solvents.

14. Deep Cleaning

The Process

Deep cleaning a new chain or a chain that is not worn is necessary, if the user wants to remove have factory grease, or lubricants applied by previous owners and users. Removal of factory grease and reside of lubrication applied by the seller is necessary before immersive waxing or the use of chain coating emulsion lubricants.

Deep clean of a chain that has been lubricated with an oil based fluid and used but not contaminated with dirt or water may be a choice or option.

A chain that that has been contaminated by exposure to dust and water, and by the products of chain wear (metal dust) may need to be deep cleaned before it is lubricated again.

A deep cleaning may may start before the chain is removed, but often involves removing the chain from the bike. It involves:

1. Removing visible contaminants and lubricants from the exterior surfaces of the chain and the drive train components that contact the chain – chainwheels, cassette cogs, derailleur pulleys. Some parts can be scraped or brushed. For other, rags can be used, or the strong blue disposable paper towel (e.g. Scott Paper Shop Towel). Some users use microfiber wipes and towels. Small amounts of detergent may be used.
2. Washing a contaminated chain with/in a detergent. This involves taking the chain off the bike. The methods include soaking, soaking and agitation, soaking and scrubbing any surface than can be reached with a scrubbing device. Some soaking is necessary to allow the detergent to contact the material to be cleaned off inward facing visible surfaces and visible on the edges of load bearing surfaces (edges of rollers and link plate). Some advice cautions against soaking a chain in detergents that may chemically interact with the chain steel, causing “hydrogen embrittlement”. Some advisors recommend automotive or aviation detergents to remove oil from metal without damaging the metal.
3. Washing the chain in solvents.

When a chain is immersed, it needs to be rinsed and dried before another substance is applied. A chain can be hung on a peg or a nail, in a dry place and left to dry. Users with the tools and time may blow compressed air through a chain.

Deep cleaning means, basically, washing the chain in solvents that remove grease and oil. Some advisers recommend soaking in the solvent before washing. The method is: immerse the chain in the solvent in a closed container, and shake it. The shaking caused turbulent flows of material in the container, including the movement of diluted grease out of the chain and clean solvent into the chain. The shaking or agitation of the chain in the container is shown in many videos on the web. (Many of the videos refer to this method a part of a program of applying paraffin by immersion.) Some use plastic bottles (bottles for Gatorade and similiar products, with wide mouths – not narrow mouthed soft drink bottles). The videos will suggest on attaching something to an end of the chain to extract the chain from the container. Removing factory grease take several rounds of immersion and agitation. It depends on what the chain manufacturer put on the chain, and on how much.

Solvent

The recommended solvent for deep cleaning is mineral spirits (“mineral terps” in Adam Kerin’s Australian English), or white spirits, a low viscocity combustible petrochemical product. Some white spirits are formulated, packaged and sold for specific applications: fuel, solvent, paint thinner or even as lubricant.

Mineral spirits, as opposed to paint thinner, are preferred for degreasing metal items. Turpentine is a paint thinner made from plant resin; it is not used for cleaning metal because it leaves residue.

In Canada, most retailers sell mineral spirits manufactured by Recochem Inc.²Business Wire: “Founded in 1951 in Montreal, Recochem has grown into a leading manufacturer and marketer of branded, private label and bulk automotive aftermarket and household fluids for consumers and industrial customers worldwide. The Company operates a global platform, with a network across North America, Europe, Australia, China, India and the Asia Pacific region. Recochem’s strong reputation in the markets it serves has earned the Company vendor appreciation awards from its customers and long-standing relationships with its suppliers and partners around the world. With innovation and agility built into its DNA, Recochem is poised to continue its expansion into global markets while maintaining its core values of exceptional customer service, consistent product quality and environmental stewardship.” in the H.I.G. Capital³Business Wire: “H.I.G. is a leading global private equity and alternative assets investment firm with $43 billion of equity capital under management. Based in Miami, and with offices in New York, Boston, Chicago, Dallas, Los Angeles, San Francisco, and Atlanta in the U.S., as well as international affiliate offices in London, Hamburg, Madrid, Milan, Paris, Bogotá, Rio de Janeiro and São Paulo, H.I.G. specializes in providing both debt and equity capital to small and mid-sized companies, utilizing a flexible and operationally focused/ value-added approach. Since its founding in 1993, H.I.G. has invested in and managed more than 300 companies worldwide. The firm’s current portfolio includes more than 100 companies with combined sales in excess of $30 billion.” portfolio under the brand name Solvable. Recochem does not offer a Solvable brand odourless mineral spirit; Recochem makes an “odourless” mineral spirit sold as Varsol, usually as a paint thinner; Varsol is a trademark of Imperial Oil in Canada.

Adam Kerin of Zero Friction Cycling has deep cleaned many chains in the ZFC business and the ZFC tests. In Episode 6 “Chain Preparation FAQ” of the ZFC YouTube series, Adam Kerin notes the differences in the removing factory grease – some chains take 3 rounds of mineral spirits but SRAM chains take 4 or 5. This was a useful aside. Removing factory grease, and using wax or a high-reputation drip lubricant appears to make a SRAM chain run silently.

Mineral spirits cut the grease, but may leave microscopic amounts of water that cause some oxidation of the metal. It is also necessary to rinse the chain with a polar solvent that will carry off any water. Denatured alcohol (“methylated spirits”) is a polar solvent. It is mainly made of industrial ethyl alcohol or ethanol. Ethanol is the intoxicating chemical in potable beer, wine and spirits. In the US, the federal government mandated during Prohibition – the rule was never changed – that industrial ethyl alcohol must be “denatured” (poisoned) with methanol to deter people drinking it and bootleggers from selling it. It is a clear fluid – no food flavouring, colour or sugar. It evaporates quickly. It is cheaper than potable spirits (hard liquor). Using potable spirits to clean a bike chain is inefficient: potable spirits contain other substances that leave residue, and it is expensive. Solvable does not offer a denatured alcohol, but does distibute methyl hydrate or methanol. Some Canadian hardware stores sell the Klean Strip brand “Denatured alcohol clean burning fuel” in the blue metal container depicted in the image on the denatured alcohol Wikipedia page (link above).

Rinsing a chain cleaned in solvent in the polar solvent allows the user to dry the chain. Again, when a chain has been immersed in mineral spirits and alcohol, it needs to be dried before lubricants are applied. Generally, after an alcohol rinse, the alcohol evaporates quickly.

Used mineral spirits may or may not be subject to hazardous goods handling rules. The used spirits are contaminated with fine particles, factory grease residue, and petrochemical lubricant residue. Mineral spirits are petrochemicals. Rules vary.

15. Etc.

New Products

There are new detergents s available in early 2024 that can dissolve oil and be used to remove factory grease or to clean a dirty oiled chain.

• Ceramic Speed manufactures UFO Drivetrain Cleaner (and UFO Clean Bearings and UFO Bike Wash).
• Silca manufactures and distributes SILCA Chain Stripper, SILCA
  Bio Degreaser and Gear Cleaner, and a few kinds of wipes and micro-fiber
  cleaning cloths.

Cleaning a Waxed Chain

This is discussed in Part 7, on immersive waxing (immersion in heat paraffin) and chain coating fluids.

One approach is to remove dust from the exterior of a chain. Modern microfiber towels are resistant to the damage of being shredded in rubbing a chain and can be washed. Chains that have been ridden a few hundred Km. in dry conditions or only for short rides in mild wet conditions can be rubbed clean and dry and simply immersed in hot wax again. This is the Molten Speed Wax manufacturer recommendation for “training chains”. The wax will get mildly contaminated, but this method can be repeated many times before the wax needs to be is discarded. A variation on this approach for more serious contamination is swishing the chain in boiling water to wash off the contaminated wax, drying the chain and putting the chain in the hot wax. Zero Friction Cycling lists the boiling water method, with these comments, among other options:

… There is no tangible benefit to boiling water flush rinses after dry rides – especially road riding where extremely little contamination will get into your solid wax lube – but even for most offroad riding unless extremely dusty – just wipe outside. …. Don’t over complicate things – basically just re wax unless fully wet ride …. With waxing just even straight re-waxing will reset contamination in chain extremely well, and a brilliant job can be done with just some boiling water.

Zero Fiction Cycling, Waxing-FAQ.pdf

A badly contaminated chain may need a deep cleaning to reset the chain to a clean condition, and an immersion in clean wax.

Table of Contents

• Endless Post
• 17. Drive Systems
  • Modern Chain
  • Other Drive Systems
• 18. Durable Chains
  • Introduction
  • Data, Records
  • Tested Chains

Endless Post

This is part 6 of 8 posts organized as a single article, individually published as posts on this blog. In March 2024 I began to reorganize and revise the long article. The sections are numbered for reference here and in the table of contents for each post.

Part/Post & Link	S.	Topics
1. Chain Wear		My discovery of wear Issues
	1	Safety Bicycles — History — Variety — Manufactured Industrially — Bike Brands — Shops or Stores — Mechanics
	2	Bike knowledge sources, Internet
	3	Bike Chains
2. Roller Chain	4	Chain Drive
3. Lubrication	5	Lubrication Theory
	6	Petroleum
4. Lubricants
	7	Fluid Lubricants — Motor Oil — Drip Lubes — Engineered — Wet and Dry marketing — Additives
	8	People and Projects
	9	Lubricant Efficiency Tests
	10	Wear tests – chains & lubricants
	11	Innovation 2022-24
	12	Consumers’ options
5. Cleaning	13	Cleaning
	14	Deep Cleaning with Solvents
	15	New Products
6. Durability	16	Modern Chains
	17	Durable Chain
7. Paraffin	18	Paraffin Wax
	19	Method
	20	Wax-compatible Drip Lubes
8. Learnings for Make Benefit		Assortment of Notes

17. Drive Systems

Modern Chain

As of 2022-2024, chain manufacturers make many kinds of chains to supply the need for replacement chains:

• Most modern bikes on the market in Canada and the USA, other than e-bikes, children’s bikes and single gear bikes, have derailleurs and rear wheel cassettes with 7, 8, 9, 10, 11, 12 or 13 cogs, and compatible laterally flexible bushingless chains;
• Some cargo bikes and e-bike manufacturers make bikes that have:
  • rear derailleurs, and flexible bushingless chains; or
  • purpose-designed chains, which may be bushed chains or wider bushingless chains than chains for road bikes, gravel bikes, mountain bikes and hybrids; and
• Older bikes requiring wider chains compatible with derailleur shifting with less cogs than modern bikes are in use.

Some chain manufacturers claim that e-bikes with the motor situated at the bottom bracket or chainwheel (as opposed to the drive wheel hub) put higher stresses on chains than chains for non-electric bikes can withstand.

Manufacturers will be making chains for years to come. The flexible bushingless roller chain is an established technology in wide use.

The bushingless, steel roller chain has a short life expectancy. To make chains thin, chains have short pins. To make chains light, link plates are thin; many chains have hollow pins. The chain is vulnerable to wear and breakage. Consumers have been “educated” by their experience with the actions and words of the bike industries to realize that some bike components have limited “service lives“, and to accept that the mean time before failure of a modern bike chain is only a few hundred hours of riding.

Adam Kerin of Zero Friction Cycling (“ZFC”) suggested in an interview by CyclingTips in 2019 that 11 & 12 speed chains are more durable, in terms of wear, than 8-9-10 speed chains due to technological innovation:

It’s commonly said that the wider chains of past drivetrains were more durable. Sure, older 8-, 9- and even 10-speed systems do offer wider cog widths which provide increased surface area with the chain, but does that actually mean the chains are more durable?

It’s a question I posed to Kerin after the previous testing was done, and he got the Zero Friction Cycling torture machine up and running again to find out. In this, he tested the top Shimano chains from each respective speed, and the results may surprise you.

…

It seems that with each gear added, durability has improved. And at least for Shimano chains, 10-speed saw a significant jump in durability from 9- and 8-speed, and Shimano’s latest 12-speed XTR mountain bike chain rules the roost as Shimano’s most durable offering.

The reasoning for this is less clear, but certain materials have improved, manufacturing processes have become refined, and new low-friction coatings have been added. Similarly, the chain designs themselves have changed, and where 8- and even 9-speed chains would see the inner links turn solely on the connecting pins, newer chains typically see these forces shared across the pins and specifically stamped plates, too.

Dave Rome, CyclingTips, 2019, Finding the Best Bicycle Chain ¹Note – defunct link

Other Drive Systems

Some internal hub systems, including planetary gear systems are in use or in development:

• Sturmey-Archer 3-speed AW internal gear hub system was used on Raleigh bicycles for many years. There are articles and resources at Bicycle Technical Information (“BTI” – the Sheldon Brown site), such as “Servicing Sturmey-Archer 3-Speed Hubs“, and other manuals and support resources. There is a BTI article on Internal-Gear Hubs.
• Shimano
  • had a 3 speed hub in the Nexus line, discussed in a 2017 article at BTI, “Shimano 3-speed Hubs“;
  • manufactured and supported the Nexus and Alfine internally geared hubs, discussed at BTI – Shimano Nexus/Alfine;
  • made an 11 speed Alfine hub (BTI). Some Alfine products/parts are still in the US market.
• Classified Cycling, situated in Antwerp (Belgium) and Eindhoven (Netherlands), introduced its Powershift system in 2023. It is available for Road, Gravel, MTB and Urban bikes by purchasing and installing new bikes or wheels with Powershift hubs and compatible cassettes. It is on some Ridley road and gravel bikes (Belgian bike brand, no dealers in Canada)

Some internal hub systems had or have a friction or coaster brake. Some are available on bikes or wheels for a disc rotor or metal rimmed wheel (for rim brakes). Most are available with a single gearwheel on the drive wheel for use with a single chainwheel gearwheel. Some recent Shimano Alfine models were also made for a belt drive.

The shaft drive and the belt drive have some history. The shaft drive appeared at the beginning of the 20th century, disappeared, and has been revived in 21st century prototypes: Ceramic Speed is raising funds for its Driven technology – a 99.2% efficient shiftable drive shaft. Belt drives reappeared late in the 20th century e.g. the Gates Carbon Belt Drive.

An alternative drive system may be an option for a home mechanic, or a shop option for an owner with the ability to pay for work and parts, if an owner can find a mechanic who can do the work.

18. Durable Chains

Introduction

Some modern laterally flexible bushingless chains on the market are durable. ZFC tested “top” Shimano 8-9-10 speed chains, and a top Shimano XTR 12 speed chain, and some other chains. In the CyclingTips NerdAlert podcast episode March 16, 2022 “Finding the best chain lube for your needs” Adam Kerin mentioned those chains, including the use of chrome in the manufacturing. The Outside Magazine sites, including its Velo (corresponding to the online verson of VeloNews) have depublished this material. Adam Kerin has discussed durable chains with other interviewers, but I have not located the interviews and passages. Adam Kerin has Chain Wear Test Results on the Chain Efficiency page. The chain wear result graph selected chains for “longevity” in terms of km in wear testing to the .05% wear mark .

ZFC initially planned tests of lubricants and tests of chains but has done more lubricant tests than chain tests. The initial 2018 document laying out the chain “longevity” (durability) testing is still online. The ZFC data chain durability is not as detailed as the material on lubricant testing. ZFC found that some chains were more durable than others in tests run with White Lightning Epic Ride dry-drip lube.

Chains by different manufacturers vary. Bike manufacturers and bike shops do not regard chain replacement as their responsibility, and do not have inventories of chains as spare parts for specific bikes. In modern commercial and economic thinking, chains are consumables. A bike shop can sell a new chain to replace a worn chain.

Not all chains by the same manufacturers are equally durable – it depends on plate, pin and roller, material, machining, metal treatment, coating, lubrication and conditions.

In an interview with Global Cycling Network tech journalist/presenter Alex Paton “They Don’t want your chain to last this long” in March 2024, Adam Kerin diffentiated some SRAM chains as better value than other chains on the basis of SRAM’s “hard chrome” treatment of chain components (which seems to be the use of chromium alloy steel plating on some chain surfaces) on those chains. Durable chains, compatible with modern drive trains and cassettes cost more.

Durable chains are not available from all manufacturers, or to all purchasers and riders in the markets of the world. Buyers and riders have lighter, thinner bushingless chains that are more vulnerable to wear. Light and thin can be cheap or expensive. Durable is more expensive. Modern chains have associated costs.

There were reports of counterfeit chains on the market during the pandemic. The elusive idea/hope buying an inexpensive durable branded chain on the internet has suffered more.

Data, Records

A rider should know when a chain was installed or lubed last, and the distances the bike has traveled. A cycling computer has a trip odometer. Keeping trip records in the device or an app requires tinkering with the device and the settings – and turning the device on. The rider may store trip data in an app that stores it in the cloud, or in spreadsheet or chart or table, or in a notebook.

Tested Chains

ZFC posted bar graphs of the durability test results in a “News” item in 2022. Some of the results are explained in CyclingTips Finding the Best Bicycle Chain article, which adds to the ZFC results:

• Some chains were retested;
• The ZFC “cost to run” results are graphed in $US.

ZFC also publishes a pdf version of a “consolidated” Chain-Efficiency-and-wear-life” results bar graph.

ZFC is attempting to measure some of the real world effects of chain construction, lubricants, and operating conditions in tests that represents the real world. Josh Poertner of Silca Velo has provided his explanatory gloss on Adam Kerin’s lubricant testing work in a couple of Silca Velo channel YouTube videos:

• Josh helps you crack the code of Zero Friction Cycling Lubricant Testing Data, August 2023;
• Josh explains more Zero Friction Cycling data set details, August 2023

In 12 speed chains, ZFC thought SRAM Eagle XX1 and X01 could run about 5,000 Km, and the Shimano XTR 9100 to about 4,000 Km., with the control lubricant a low quality “dry” drip lube, based on pure elongation results. The ZFC lubricant tests indicate that a high quality chain will last longer with paraffin lubrication. ZFC suggested, in an extrapolation calculation in the lubricant testing spreadsheets, that a few specific modern Shimano chains, immersion waxed, can be run for 25,000 Km. ZFC is not always consistent in predictions and estimates; its comments refer to specific chains, and not to manufacturers or brands.

Will what manufacturers of the tested durable chains have done be replicated in production lines of chains by any manufacturer?

The best 11 speed chains in the elongation tests, among those tested by ZFC, at over 3,000 Km., were SRAM XX1, Campagnolo Record, and YBN SLA-110. ZFC found, in its cost to run 10,000 KM. calculations, several chains at about $500 (Australian), or about $200 (US), making assumptions about chain replacement and other drive train component replacements. The cost to run numbers in US dollars are in in a bar graph. Several chains show at a price to buy $150-$200 US per 10,000 Km. Online or retail stores list economy and mid price bike chains under the SRAM and Shimano brands from $30 to $50.

ZFC sells the following chains, in bundled waxed chain sales, as of 2024 (not counting some chains for e-bikes²ZFC discloses the shipping costs to consumers outside Australia – more emphatically than most e-commerce sites. I have not matched the description in the ZFC store to the desciptions in the test charts):

10 speed	11 speed	12 speed	13 speed
			Campagnolo Ekar
	Campagnolo Record	Capagnolo Super Record – C-Link
	Shimano HG-901/XTR	Shimano M9100
		Shimano M8100
		SRAM AXS UFO
		SRAM AXS Road
		SRAM AXS Eagle
YBN-SLA 101	YBN SLA-110	YBN SLA Ti-N

Adam Kerin was cited by CyclingTips in”Finding the Best Bicycle Chain” (The Outside Magazine sites, including its Velo site, corresponding to the online verson of VeloNews,the owner have depublished this material) as regarding the Campagnolo Record and YBN SLA as “excellent choices”. Adam Kerin did not distinguish between YBN 11 speed SLA chains – SLA 110 and SLA 1100. YBN chains can be ordered from MSpeedwax in the USA and other regional dealers elsewhere, including ZFC in Australia. MSpeedwax lists the SLA-110 chains at about $70 US.

Adam Kerin stated, under the heading “How Long will waxing last?”, on the Waxing Instructions page:

Re-waxing by recommended 300 Km. mark, the average for a top quality chain like YBN to get to recommended wear replacement mark of .5% is 15,000 Km.

….

Erring on the earlier side. i.e. re-waxing in the 200 the 250 mark [range] brings a big jump in chain and drive train life span again. From 100 Km. post re-wax there is literally zero wear … From 100 to 200 Km., the friction and wear increase is minute.

Table of Contents

• Preliminary
  • Endless Post
  • Scope
• 5. Theory
  • Development of theory
  • Bicycle Chain Drive Train
    • Introduction
  • Plates and Pins
    • Chain Lubrication
    • Fluid Lubricants
  • Research
    • Materials
    • Professional organizations
    • Academic
    • Industrial
  • Basic terms
  • Penetration and distribution
  • Unsuitable
  • Factory Grease
  • Additives
• 6. Petroleum
  • Source & Refining
    • Motor Oil
    • Gear Oils
    • Limits and Constraints
  • Bike Drip Lubes
    • Wet and Dry
  • Solids
  • Paraffin Wax

Preliminary

Endless Post

This is part 3 of 8 posts organized as a single article. individually published as posts on this blog. In March 2024 I began to reorganize and revise the long article. The sections are numbered for reference here and in the table of contents for each post.

Part/Post & Link	S.	Topics
1. Chain Wear		My discovery of wear Issues
	1	Safety Bicycles — History — Variety — Manufactured Industrially — Bike Brands — Shops or Stores — Mechanics
	2	Bike knowledge sources, Internet
	3	Bike Chains
2. Roller Chain	4	Chain Drive
3. Lubrication	5	Lubrication Theory
	6	Petroleum
4. Lubricants
	7	Fluid Lubricants — Motor Oil — Drip Lubes — Engineered — Wet and Dry marketing — Additives
	8	People and Projects
	9	Lubricant Efficiency Tests
	10	Wear tests – chains & lubricants
	11	Innovation 2022-24
	12	Consumers’ options
5. Cleaning	13	Cleaning
	14	Deep Cleaning with Solvents
	15	New Products
6. Durability	16	Modern Chains
	17	Durable Chain
7. Paraffin	18	Paraffin Wax
	19	Method
	20	Wax-compatible Drip Lubes
8. Learnings for Make Benefit		Assortment of Notes

The project took several months. Since then, I have edited and revised further.

Scope

This Part:

• contains cumulative section 5. which addresses the lubrication of steel roller chains, and
• contains cumulative section 6, which addresses the history of the extraction and refining of petroleum oil and various kinds of lubrication products.

It discusses lubrication theory for bicycle roller chains from the start of the safety bicycle era (i.e. after 1888) to the early 21st century.

Part 4 of this series will consider consumer-led testing, data-driven assessment of lubricants. Parts 4, 5 and 7 will discuss and some early 21st innovations in chain lubricants and cleaning chemicals.

5. Theory

Development of theory

The idea of lubricating a steel roller chain with oil made was based on observation. Some lubricating fluids did not flow off the chain and were not flung off by the forces of motion. Some fluids adhered to the chain, and lubricated, for long enough, to allow the chain to move under “load” and serve a purpose. In industry, oilers, specialized employees, lubricated open bearings in various devices with lubricating “oils” in the 18th and 19th centuries. This continued into the 20th century in many industries.

The industrial view, historically, was that

• lubrication of the contact surfaces of machinery allowed parts to move and reduced the wear on metal parts; and
• generous lubrication with fluid lubricants was to be preferred to low lubrication.

People can see what happens when a chain is soaked in solvent. Dirty solvent to see that washes out of the chain. Bike people use mental models of what happens in a chain to explain opinions about what happens and how it works.

The model of how lubricants worked in the 19th century and the first half of the 20th included that lubricants reduced friction and broke down and washed out the products of corrosion (rust) and contamination (dirt, products of operation of a chain, or products of a machine or system, such as combustion).

Engineers and scientists worked out many principles and applications of organic chemistry and chemical engineering in the 19th century, before the modern theories of atomic bonding were established and before the periodic table of elements and other fundamental theories of physics and chemistry were articulated.

Bicycle Chain Drive Train

Introduction

The right way to lubricate a bike chain is contentious among cyclists and mechanics. The mechanic and pioneer cycling Web writer Sheldon Brown observed:

Chain maintenance is one of the most controversial aspects of bicycle mechanics. Chain durability is affected by riding style, gear choice, whether the bicycle is ridden in rain or snow, type of soil in the local terrain, type of lubricant, lubrication techniques, and the sizes and condition of the bicycle’s sprockets. Because there are so many variables, it has not been possible to do controlled experiments under real-world conditions. As a result, everybody’s advice about chain maintenance is based on anecdotal “evidence” and experience. Experts disagree on this subject, sometimes bitterly. This is sometimes considered a “religious” matter in the bicycle community, and much vituperative invective has been uttered in this regard between different schismatic cults.

This article is based on my personal and professional experience and my own theories. If you disagree with them, I won’t call you a fool or a villain, you may be right. I hope you will extend me the same courtesy.

Sheldon Brown. “A Religious Question”, Chain Maintenance section, Bicycle Technical Inf0 pages.

Plates and Pins

The bicycle roller chain is made of materials and components developed in 19th century. Inventors, engineers, manufacturers, and mechanics, unable to observe microscopic spaces inside the rollers of roller chain, relied on evidence other than direct observation, and draw inferences. While microscopes and electron microscopes can view surfaces at a nearly molecular scale, no one has observed the events on the surfaces inside a moving roller chain.

Some one of the inferences is that lubrication reduces friction but does not stop metal surfaces in contact “under load” (i.e. with force) from wearing. Some modern riders are not aware of wear, and regard it as a sinister excuse to service bikes and sell bike parts. The modern efforts to explain maintenance have led modern engineers to use new tools to prove that wear is real, and to explain what can be done to make bike chains work properly and last longer. Electronic magnifying glasses and microscopes can make still pictures and videos of chain links. Some social media producers are using these tools to explain and illustrate bike chain operations. 2024 videos by Silca Video

• April 11, 2024, Stop Wasting Your CHAIN LUBE! Know the BEST Way to Apply It! shows the effects of surface tension in moving liquids into the spaces of a bike chain, in slow motion;
• June 26, 2024, Chain QUICK LINKS: Are they keeping you from waxing? shows the fine parts of master link and paraffin wax on a hot-waxed chain.
• July 30, 2024, Microscopic Magic: Save Your Chain from Wearing Out!

Bicycle chains are manufactured on the assumption that the user/owner of the bike or a mechanic will maintain, clean and lubricate the chains at the expense of the user/owner

A bike chain has to bend at the pins several times every time the chain travels the loop from the chain wheel to the gears on the drive wheel. The chain bends around the pins as the chain goes around the chain wheel, the jockey pulleys and the gear on the driving wheel. There is metal to metal contact between:

• rollers and
  • the bushings of a bushed chain or the half bushings (on the inner surfaces of inner link plates) of unbushed chain, and
  • the inner sufaces of outer link plates;
• the pins and
  • inner link plates, and
  • outer link plates.

Most or all of these areas need lubrication.

The moving parts of bicycle chain are “open” bearings (i.e. not sealed).

Silca Velo (Josh Poertner or his team¹ discussed in post # 4 in this series) explained bike chain lubricants in a blog post Chain Friction Explained published in December 2021. The drawings in that post show plates, rollers and pins and the locations that fluid lubricants should be applied. Silca explains the theory that a lubricant forms a film that lubricates the metal surfaces, preventing the metal surfaces wearing each other down. (Wax penetrates at these points when the wax has been melted to a fluid and lubricates when the wax is solid after the chain has cooled, or the carrier fluid has evaporated).

Chain Lubrication

An article at the web site BikeGremlin in 1986, when it was a text based Web site, described the goals of engineers and mechanics, the science of lubricants and goals of chain lubricants:

5.1. Good rust protection and resistance to water wash off.

5.2. Good adhesion, i.e. remaining between the pins and the rollers, without leaking out, as long as possible. Keeping the chain well lubricated and running quietly.

5.3. Cleanliness, i.e. not sticking dirt to itself and thus making the chain dirty.

5.4. Low price – so that chain lubrication doesn’t cost more in the long run than replacing chains more often

https://bike.bikegremlin.com/1986/bicycle-chain-lubricants-explained/#5

However, that article like many written for cyclists, does not explain how lubricants were believed to operate.

Fluid Lubricants

Fluid lubricants applied to the joints between links of bike chains will penetrate the spaces between the moving metal surfaces. The lubricant is believed to form a film. The lubricant adheres to each surface and slips or sheers. A lubricating fluid for a roller chain needs to have properties of:

• viscosity (the resistance of a fluid to shearing flows) – low (thin) to flow (run), but enough to form a film, and
• adhesion – enough to stick to the metal and not be disrupted by the forces that are acting on the chain.

Adhesion requires a lubricant to adhere to metal and form a film. It is hard to prevent dirt adhering to a chain treated with some lubricants, and hard to prevent a chain from getting wet under some conditions.

BikeGremlin discusses achieving correct viscosity and water resistance in an oil based liquid lubricant:

[Water resistance] is practically independent of particular lubricant’s properties. For example, a lubricant that is resistant to water washout will be even more resistant if more viscous, and less resistant if “thinned”. It may still be better than another lubricant that isn’t resistant to water washout, but viscosity has a significant effect on a wet lubricant’s characteristics and performance, besides the lubricants inherent characteristics.

Another thing to consider is that viscosity changes with temperature change. The colder it is, the thicker a wet lubricant gets, while in summer heat viscosity (drastically) drops.

Because of all this, each must choose for themselves an optimal wet chain lubricant viscosity, based on riding conditions (temperature, rain, dirt, sand etc.) and how often they (want to) clean and lube the chain. Trade offs are given in table 3.

https://bike.bikegremlin.com/1986/bicycle-chain-lubricants-explained/#8

BikeGremlin suggests motor oil (the oil used in the crankcases of 4 cycle internal combustion engines) was and would be is an adequate chain lubricant, except for additives:

Monograde engine oils, with SAE 10W, or even SAE 30 viscosity, thinned down with diesel fuel (from 4:1, to highly thinned in 1:4 ratio), can be decent bicycle chain lubricants.

Engine oils of lower API grade class (API SF, or API SG), preferably monograde, for petrol (not diesel) engines, are the better choice than modern, higher API class engine oils, because they contain less detergents and other (needles, or harmful for bicycle chain lubrication) additives.  As was explained in chapter 6.1, in case of multigrade engine oils, the first mark (before the “W”) is relevant for determining viscosity for bicycle chains lubrication.

As far as viscosities go, SAE 30 is a decent summer candidate (“thinning” with diesel per one’s taste), while SAE 10W is OK for the winter (also with “thinning” if required).

Rough SAE viscosity recommendations for motor oils, for the summer: SAE 10W use straight SAE 30 thinned with diesel in ratio 3(oil):1(diesel) SAE 50 thinned with diesel in 1:1 ratio

….

Engine oils are designed to work within enclosed engine compartment. That is why they are not water washout resistance champions, while additives they have don’t help with bicycle chain lubrication, quite the contrary. However, these shortcomings are not severe enough to make (much) measurable difference from other oil types. Of course, as the following chapters will show, there are better options.

Ibid.

BikeGremlin said that light machine oil, for instance sewing machine oil, had the right viscosity to be used to lubricate bicycle chains.

Fluid lubricants that disperse and suspend in air as aerosols. Aerosols require fluid to be mixed with a gas and propelled to the point where the fluid is to be applied by a pump or pressurized source. Some aerosol lubricants are general purpose and some are for motorcycle drive chains, chain saws, or other chain drives.

Research

Materials

Materials used in manufacturing roller chain meet standards set by ASTM International, formerly known as American Society for Testing and Materials, an international standards organization that develops and publishes voluntary consensus technical standards for a materials, products, systems, and services. One relevant standard is ASTM-G77: Standard Test Method for Ranking Resistance of Materials to Sliding Wear Using Block-on-Ring Wear Test. The method “covers laboratory procedures for determining the resistance of materials to sliding wear. The test utilizes a block-on-ring friction and wear testing machine to rank pairs of materials according to their sliding wear characteristics under various conditions.” A testing machine is shown in a video published by Silca Velo ²a firm discussed in Part 4 in this series which promotes Silca Velo’s drip lubricant Synergetic and criticizes other specific brands of bicycle chain “drip lubes”.

Professional organizations

American lubrication engineers formed a learned society in 1944; lubrication engineering reformulated its parameters and boundaries and now calls it area of expertise “tribology“. It is not molecular nanotech, but it studies and explains the interactions of materials including nanomaterials on moving surfaces. The name of the American Society of Tribologists and Lubrication Engineers was modified. Tribology is not a regulated profession – there is no law or process to prevent any person calling themself a tribologist.

Academic

There is proprietary industrial research, but the results are not published. A university may fund research, but academic researcher need funding, and need research to be sponsored or commissioned. In the neo-classical economics that dominates thinking about innovation, markets and consumption, an innovator can disrupt an industry and established manufacturers – if the invention can attract capital investment, which requires financial engineering.

Research published in academic and trade journals is usually published in the journals used in one of the subfields of the applied science of engineering. There is a good deal of published research on lubrication of industrial machines. Published academic research on bicycle drive trains was scarce for decades. People in business paid attention to published research and used it in developing and marketing products

Josh Poertner of Silca Velo discussed the development of Silca Synergetic, an oil based fluid chain lube, in his Marginal Gains podcast in November 2020 Lubes & Chains & Marginal Gains. His vision of the role of universities and industry in research was:

… it is 100% the job of the people doing the basic science to figure this [what is the reason this works] out … my place in the world is to turn this research into a product that people can get their hands on”

Marginal Gain Podcast: Lubes & Chains & Marginal Gains

Engineers believe that lubricating fluids can be designed and manufactured to flow while carrying particles of solids in suspension. The academic literature is largely gated or fenced behind publishers’ paywalls. For instance, a chapter on “Applications of Fluorinated Additives for Lubricants” on the 2012 book Fluoropolymer Additives, published by Elsevier, appears to discuss the use of PTFE (Teflon) and other additives in bike lubes.

The academic literature on bicycle chain lubrication was sparse until after 2001. A modern (paywalled/gated) paper by James B. Spicer, published in the Journal of Mechanical Design, in 2001, “Effects of Frictional Loss on Bicycle Chain Drive Efficiency” addressed lubrication. Subsequent published research by Prof. Spicer addresses drive trains for e-bikes. The abstract of the 2001 paper stated:

Chain drive efficiency has been studied to understand energy loss mechanisms in bicycle drive trains, primarily for derailleur-type systems. An analytical study of frictional energy loss mechanisms for chain drives is given along with a series of experimental measurements of chain drive efficiency under a range of power, speed and lubrication conditions. Measurements of mechanical efficiency are compared to infrared measurements indicating that frictional losses cannot account for the observed variations in efficiency. The results of this study indicate that chain tension and sprocket size primarily affect efficiency and that non-thermal loss mechanisms dominate overall chain drive efficiency.

James B. Spicer (of Johns Hopkins University) and others, Journal of Mechanical Design, Volume 123, p. 598 (2001)

In a press release by Johns Hopkins University, Prof. Spicer is quoted (emphasis added in this post):

The researchers found two factors that seemed to affect the bicycle chain drive’s efficiency. Surprisingly, lubrication was not one of them.

….

The Johns Hopkins engineers made another interesting discovery when they looked at the role of lubricants. The team purchased three popular products used to “grease” a bicycle chain: a wax-based lubricant, a synthetic oil and a “dry” lithium-based spray lubricant. In lab tests comparing the three products, there was no significant difference in energy efficiency. “Then we removed any lubricant from the chain and ran the test again,” Spicer recalls. “We were surprised to find that the efficiency was essentially the same as when it was lubricated.”

“The role of the lubricant, as far as we can tell, is to take up space so that dirt doesn’t get into the chain,” Spicer says. “The lubricant is essentially a clean substance that fills up the spaces so that dirt doesn’t get into the critical portions of the chain where the parts are very tightly meshed. But in lab conditions, where there is no dirt, it makes no difference. On the road, we believe the lubricant mostly assumes the role of keeping out dirt, which could very well affect friction in the drive train.”

John Hopkins University News Release, August 19, 1999

The stated speculation is why lubricants still work as real chains get dirty and are sprayed with water. The article and news release did not say which lubricants were best.

The researcher addresses efficiency in transmitting power. The researcher does not say that chain should not be lubricated. The researcher speculates that a bicycle lubricant may contribute to energy efficiency in the real world where bicycles are used. The Johns Hopkins tests were full Load Tests (see post # 4 in this series) which had a range of error of +/- 1 %.

Industrial

Industrial discoveries are guarded from imitation and distribution by employee loyalty and legal mechanisms to protect the advantages of existing manufacturers and of innovators. Lubrication engineers, tribologists, and other experts, whether employed by academic institutions or businesses developing and selling products, refer to standards to describe and measure things that are believed to happen according to physical laws.

Lubrication engineers working for private enterprise began to develop specialized “bicycle chain” lubricant fluids in the 1960s and 1970s.

In the early and middle parts of the 20th century, the lubrication and bearing industries developed tests and equipment. The Timken OK Load was a device manufactured and sold by the American manufacturer, the Timken Company. The test method was known as block and ring. ASTM International (formerly the American Society for Testing and Materials) sets standards. The ASTM standard for block and ring testing is ASTM G77,, as last revised in 2017. The paper that lays out the ASTM G77 process is paywalled. The process can be followed with small testing machines that applying known force (a weight on lever) to a sample block of metal against a metal ring turned by the energy of an electric motor at a known speed. These devices are used in industry to test or demonstrate the effects of lubricants in reducing friction. It would be remarkable if any cyclist had such a friction testing machine or the knowledge and skill to use it. ASTM developed a process that manufacturers of bearing and lubricants can follow, but does not certify the tests performed by manufacturers. I am not aware of any agency or body that tests lubricants and certifies that lubricants consistently meet standards. ASTM does not have, as far as I can tell, standards for bicycle chains and lubricants. Bike chain lubricant manufacturers do not to refer to ASTM G77 or any ASTM standards.

Racing was a dominant factor in promoting sales of bikes and parts in the bicycle industry in the affluent parts of the world in the 20th century. Manufacturers publicized their products based on the achievements of racing teams, team leaders and stars. The bicycles sold in parts of the world changed in the 1960s and 1970s. Some riders learned how to repair road bikes. Some riders began to modify and build bikes – this is the origin story of how the first mountain bikes were made, and of many companies selling goods and services to cyclists. The firms manufacturing drive train components developed product lines for road bikes, mountain bikes and for gravel bikes.

Basic terms

The article from BikeGremlin, above., explains lubricating oils, the concept of viscosity, US Society of Automotive Engineers (“SAE”) standards of viscosity of motor oil (SAE has a separate standard for gear oils), and the ISO VG standards. The SAE numbers are usually visible on a container. The ISO VG standard is not necessarily marked.

A couple more terms:

• Carrier fluid is a term used by engineers and other specialists who deal with the distillation of petroleum, and manufacturing and using lubricants. “Carrier fluid” was not a Wikipedia entry, as of January 2022, but is used in several entries. Carrier fluids have been used in industrial chemistry and manufacturing for over 60 years (as of 2022) to dissolve polymers and oligomers, and transport additives to surfaces where the additives lubricate the surfaces. Chemical firms manufacture and sell their own proprietary carrier fluids. Dow brands its carrier products as UCON. 3M has branded its carrier products and solvents as Novec. There are a number of published papers on carrier fluids and additives in industries.
• Base oils refers to refined petroleum or synthetic lubricating oils with lubricating properties.

Many carrier fluids dissipate or evaporate, in theory leaving a coat of lubricant(s). Some carrier fluids are highly volatile – they evaporate. Some are solvents. The online Encyclopedia Britannica has an entry on solvents and carrier liquids in the application of surface coatings. Journalists and tech writers at CyclingTips used the term carrier fluids as early as 2008. Lennard Zinn mentioned it in columns and articles in Velo News in 2013 and 2014.

Penetration and distribution

A fluid film can be displaced, disrupted, or diluted by the operation of the device or the introduction of foreign liquids such as water. The mains ideas about chain lube were/are that it should be thin enough to penetrate into the spaces where metal surfaces are in contact, and viscous enough to maintain a film, and it should adhere to the metal parts and form a film coating the metal parts it is protecting. A bicycle chain only needs a few drops of an effective lubricant to form a film or deposit a coating in the spaces between the moving metal surfaces that bear on each other in bike chains. John Allen at Bicycle Technical Information (“BTI” or Sheldon Brown’s pages), noted:

There are three points where a chain needs lubrication. First, and most importantly, the link pins need to be lubricated where they move inside the inner links as the chain bends and straightens. Second, the insides of the rollers need lubrication to let them revolve freely around the bushings as they engage and disengage the sprocket teeth. If the rollers don’t roll, they slide along the sprocket teeth, causing accelerated sprocket wear. Third, the surface where the outer side plates overlap the inner side plates can benefit from lubrication as well, although this contact surface is much more lightly loaded than the first two.

When a conventional [bushed] chain is oiled, before oil can reach inside of the bushings to lubricate the link pins, it has to pass between the inner side plates and the outer side plates. With usual oiling techniques, such as sprays, the oil tries to get into both ends of the bushing at once. Air bubbles can get trapped in the space between the link pins and the bushings, and with oil at both ends of the bushings there is no place for the air bubbles to escape. In addition, the cracks between the inner and outer side plates are highly exposed to road dirt, and are often quite grungy. Thus, even if you are able to get oil into the bushing, it is likely to be contaminated.

The air bubble problem may also exist with lubricant flow into the inside of the roller to let it turn freely around the bushing, but the shorter length and larger diameter of the roller, compared to the inside of the bushing, probably make this a non-issue. The contamination problem here is also probably less severe, because the sprockets tend to clean the rollers automatically.

With bushingless chains, the lubricant flow is entirely different. If oil is applied to the rollers, it can easily flow into both sides of the rollers, because air (and oil) can flow through the gap between the “half bushings”. If a bushingless chain is oiled only on the rollers, for instance by a narrow-spout oil can, the oil is able to flow into both sides of the rollers, through the gap and onto the middles of the link pins. The oil then flows out along the link pins to the side-plate junctions. Since the side plates are oiled from the inside, there is a natural self-flushing action that brings dirt and sand out of the chain instead of into it.

The outside of the rollers is cleaned by contact with the sprockets.

Sheldon Brown & John Allen, BTI, on Chain Maintenance

John Allen noted:

… the Sunbeam oil-bath full chain case solved the problem in 1908.

Brown & Allen, BTI, Chain Maintenance

David V. Herlily’s Bicycle – the History (2004) said that an oil bath was designed by the English innovator John Marston, of Sunbeam Cycles, Wolverhampton, U.K. and featured in the Golden Sunbeam model. Versions of the Golden Seabeam were manufactured for several years after 1896. Oil baths has been developed for use with roller chains in industrial settings.

Many driving chains … operate in clean environments, and thus the wearing surfaces (that is, the pins and bushings) are safe from precipitation and airborne grit, many even in a sealed environment such as an oil bath.

Wikipedia, Roller Chain#Lubrication

Oil baths were featured on some motorcycles. Many modern motorcycle drive trains have sealed bearings. However oil baths and sealed bearing have not been accepted by bike designed and riders.

An uncovered chain needs to be cleaned and lubricated. Generally cleaning should precede lubrication. Sheldon Brown, published material by the California engineer and cyclist Jobst Brandt in the BTI pages:

… the chain should be cleaned of grit before oiling, and because this is practically impossible without submerging the chain in solvent (kerosene, commercial solvent, or paint thinner), it must be taken off the bicycle. Devices with rotating brushes that can be clamped on the chain while on the bicycle, do a fair job but are messy and do not prevent fine grit from becoming suspended in the solvent. External brushing or wiping moves grit out of sight, but mainly into the openings in the chain where subsequent oiling will carry it inside.

Jobst Brandt, Bicycle Technical Information, January 10, 2002, revised November 23, 2004, Chain Care, Wear and Skipping

Regarding lubricants and contaminants in bushingless chains:

Pins inside full bushings … are well protected against lubricant depletion because both ends were covered by closely fitting side plates. Some motorcycle chains have O-ring seals at each end. In the swaged bushing design there is no continuous tube because the side plates are formed to support the roller and pin on a collar with a substantial central gap. In the wet, lubricant is quickly washed out of pin and roller and the smaller bearing area of the swaged bushing for the pin and roller easily gall and bind when lubrication fails. Although this is not a problem for this type of chain when dry it has feet of clay in the wet.

Jobst Brandt, Chain Care, Wear and Skipping, at Bicycle Technical Information, January 10, 2002, revised November 23, 2004

That was not the way that most users maintained bicycles, or the way most mechanics had been doing things at that time. It showed some riders and mechanics the benefits of cleaning chains separately from lubricating chains, and keeping chains clean.

Unsuitable

BikeGremlin pointed out that several fluid lubricants may achieve the goals of chain lubrication in its post or article Comparative overview of bicycle chain lubricants, but also that several fluids are unsuitable. Solvents and multi-use household mineral oils are not suitable for use as bicycle chain lubricants. In the BTI pages, Sheldon Brown & John Allen listed lubricants not to be used on bicycle chains:

Automotive motor oil contains detergent, to wash away combustion products, and is made to be renewed constantly under pressure from the motor’s oil pump. I [John Allen] rode once with someone who had used it the day before, and her chain was already squeaking.

“Household” oil, such as 3 in 1, lacks extreme-pressure additives and is acidic. It tends to gum up. (It’s really bad news inside internal hub gears, too…)

WD-40 and other thin sprays are intended more as solvents than lubricants. They evaporate quickly.

Brown & Allen, Bicycle Technical Information (Sheldon Brown pages) Chain maintenance

Many lubricating fluids can transport substances that adhere or bond to the metal and create a lubricating coating. In the language of tribology, a chain lubricant might form a tribofilm if the lubricant chemically reacts to the metal. Some drip lubes are marketed as made of enhanced lubricants or as containing cleaning agents and lubrication enhancing substances:

• waxes,
• PTFE (Teflon),
• carbon tubes,
• zinc dialkyl dithiphosphates (ZDDP), molybdenum disulfide, tungsten disulfide and other metallic additives; and
• nanoparticles or other substances.

Mixing additives into oils (refined or synthetic) is accepted in the petroleum and chemical industries. “Detergent” additives detract from the usefulness of automobile motor oil as a bicycle chain lubricant.

The idea of mixing detergents and oils tempts marketers to advertise bike lubes as both lubricating and cleaning. This is a difficult combination for bicycle chain oils. It is tempting to slather new oil on a chain, wipe off the muck and believe that the new lube has replaced or diluted the dirty oil in the chain.

Factory Grease

All bicycle chains are covered in “factory grease” when shipped from the factory. Many bike owners believe it is,or similar to, cosmoline, an anti-corrosive coating developed to ship metal products across the oceans in the 1930s and 1940s, and used to ship US military materials across ocean during WW II. Cosmoline is not a lubricating grease, but chain manufacturers do not disclose that they are using and how it was installed. Some chain manufacturers – e.g. Shimano – claim their factory grease is a lubricant.

Factory grease holds dirt because any dust in the air adheres to this grease. Factory grease on the outside of the link plates should be wiped off. Factory grease adheres to metal surfaces and interferes with the application of clean lubricants to surfaces that should be lubricated. Removing the chain and cleaning with solvents or special products to remove factory grease is necessary to lubricate a chain by immersion in melted paraffin. It is considered by many to be helpful in cleaning chains that have been used with most or all fluid lubricants.

Almost or all bike shops install the manufacturer’s chain, with factory grease, on new bikes. The assumption is that the buyer or a mechanic will start to apply a lubricant to the chain. Some shops may apply some bike chain lube to make the chain sound more quiet and perform when a test rider shifts gears. Bike shops will not strip factory grease unless the buyer asks for the service, pays for the added labour, and assumes the risk. Removing factory grease takes intensive cleaning, which involves removing the chain, and soaking the chain in solvent. Removing the chain, even with master links, is a task. The use of solvents to remove factory grease or to clean a chain raises a logistic and application problems.

Additives

Manufacturers claim that lubes can deliver additives that would form films or tribofilms on the bearing surfaces. This claim has been made for other lubricant products – greases enhanced with particles of “molybdenum” – actually molybdenum disulfide are popular in industry and wth home mechanics. Many bicycle chain lubricants on the market, including most dry lubes, do not demonstrate the results suggested by manufacturers. Efficiency data could be interpreted as demonstrating that drip lubes could reduce friction , or that drip lubes reduced friction for a short period after being dripped into a chain.

The author of Bicycle Chain Lubricants Explained at the web site BikeGremlin discusses the use of additives in “dry” drip (fluid) lubes.

Polytetrafluoroethylene (“PTFE), better known as Teflon, is a low friction substance, as a solid. Teflon is known as an ingredient of the coatings of frying pans, woks and other cookware. The challenges of getting a non-stick coating to stick to metal surfaces are nearly obvious. No bicycle chains are coated with PTFE, or any soft coating, when manufactured. Teflon has been a popular additive for household lubrication products and for chain lubes. The benefits of PTFE coating applied in carrier fluid drippers, in theory, would be substantial. Dry-drip lubes with PTFE include or included at one time:

• Finish Line Dry Teflon. Finish Line still advertised Dry Teflon bike lube in 2022. It was scarce in some markets in 2021 & 2022; the price has been going it up. Finish Line at times maintained the Dry Teflon product has been replaced by another Finish Line product – an aerosol spray for motorcycle chain. Some consumers maintain in cycling forums that Dupont Multi-Purpose Lubricant with Teflon, manufactured by Finish Line. is an effective replacement for Finish Line Dry Teflon bike lube;
• Dupont Teflon Bike Lube and
• Rock ‘n Roll Pro-Gold and Absolute Dry.

Efficiency tests³See discussion in Part 4 of the series of PTFE enhanced products were favourable to some products, but the interpretation was not clear. PTFE has been identified as a “forever’ chemical and has been avoided in many applications.

WS₂ (Tungsten disulfide) and ZDDP(dialkyldithiophosphates) have been added to some products. Efficiency and wear testing have been favourable. The theoretical model is that these additive combine to coat load bearing surfaces with a lubricating tribofilm.

Several products are said to have microscopic or submicroscopically small (“nano”) lubricating particles, of durable material (Ceramic?, graphene, carbon) of some particular shape (spherical? to resemble ball bearings?). It is hard to sort out conceptual models from marketing metaphors, hype and puffery without testing and data. Drip lubes with nano particles have performed poorly in wear testing by Zero Friction Cycling. The new Finish Line paraffin lubricant with Tungsten nano spheres has been astonishingly bad in the first block of the ZFC lubricant wear tests ⁴ZFC and wear testing are discussed in Part 4 in this series.

In the video Microscopic Magic: Save Your Chain from Wearing Out! on Silca Velo’s YouTube channel July 30, 2024 Silca Velo is discussed in Part 4 of this series, Josh Poertner suggested that in a model of lubrication of the rotation of the roller of roller chain around the pin and bushing, particles of some additives interfere with lubrication. He suggested that fluid or waxes should form a film and additives should coat the metal parts of the chain to promote lubrication.

6. Petroleum

Source & Refining

Industry relied on natural oils and fats – vegetable oils and animal fats (including by-products of whaling) as lubricants until after development of the industrial refining of petroleum began in the 1840s and 1850s. Most natural oils and lubricants, according to modern science, are based on esters.

Petroleum is the remnants of ancient plants and animals, trapped in rock, that can be brought to the surface, “refined” (distilled,) and processed (cooked) into more pure useful substances that serve purposes. The refining process separated combustible “spirits” from heavier oils. Petroleum was referred to as a “mineral” oil because it was extracted from deep below the surface of the earth. The history of the geological oils is addressed in works on geology, industry and ecology. Some works have focused on the uses of the combustible spirits as fossil fuels, or as direct energy sources. For instance, Vaclav Smil’s 2010 Energy Transitions: History, Requirements, Prospects.

Engineers, scientists and inventors worked systematically and scientifically with coal tar, coal oil, petroleum, and other raw or processed material to get fuels, dyes, detergents, solvents, lubricants and pharmaceuticals.

The fluid lubricants used in industry and with motor vehicles have been manufactured products made with refined petroleum oils since the late 19th century. Refined and chemically engineered petroleum is used to manufacture many modern products:

• combustible fuel (gasoline or petrol, kerosene);
• lubricants (motor oil and other lubricating and “mineral” oils);
• mineral spirits: solvents, paint thinners and cleaning products;
• paraffin;
• plastics; and
• modern synthetic oils.

Most modern lubricants are made of refined petroleum products. Some lubricants have been lightly refined. Some have been chemically engineered.

Motor Oil

Through most of the 20th century automotive engine oil (motor oil) made of refined petroleum oil was widely available and inexpensive. Low viscosity motor oil was easily dripped or trickled onto bicycle drive chains with small oil cans. Oil could penetrate. It could loosen oxidized metal (rust), and withstood some of the rigors of use as a chain lubricant. Motor oil in internal combustion engines needs to be filtered and regularly replaced. (Fuel and air are also filtered. Fuel has to be stored and managed to avoid contamination with water, dirt or the products of corrosion in the storage vessels.)

Motor oil is made by refining crude oil to with a base stock that must be capable of flowing and adhering to metal surfaces. The refined oil is engineered further to turn it into motor oil. There are differences between refining oil and manufacturing chemicals, but only a chemical engineer could understand it.

The production of automotive lubrication oils became specialized. The oil industry changed the way it makes and sells motor oil. Among other things, Oil industry engineers developed Polyalphaolefin and other “synthetic” base stocks for motor oil for racing, and other premium motor oils.

Chemical engineers also developed some lubricants and additives manufactured with polymers including chemical that are believed to coat metal with lubricating polymers. Such lubricants, like motor oil and other fluids, adhere to dust and grit and to metal dust produced by metal on metal wear. In the video Microscopic Magic: Save Your Chain from Wearing Out! on Silca Velo’s YouTube channel July 30, 2024 Josh Poertner suggested (at about 4 to 5 minutes in the video) that polymer lubricants (he gave Dumonde Tech as an example, referring apparently to Dumonde Tech Original Bike Chain Lube; he alluded to similar products made by Finish Line) trapped particles that contribute to chain wear and dried to form a plastic film on a chain. His video showed a 10 speed chain, heavily worn after 2200 miles of use (and very little cleaning and maintenance)

Motor oil is more viscous that other lubricating oils to operate in the hot conditions of internal combustion engines. Motor oil was widely used to lubricate motorcycle and bicycle drive chains, but is no longer the preferred chain lube. Modern motor oil has additives to help remove the residue of combustion. The additives can chemically affect the surface of metal; few of the additives in motor oil improve oil as a lubricant for bike chains. Many lubrication engineers maintain that these additives interfere with lubricating roller chains. Several factors explain the shift:

• the price of oil changes;
• refineries have changed the way oil stocks are allocated;
• motor oil was a thick or heavy oil and had the drawbacks of “wet” lubes.
• Removing dirty oil from a chain could require the removal of the chain and the use of solvents. Without master links and other chain removal tech this was a major task, and it still not a minor task;
• environmental factors made it harder to deal with waste material – excess oil and solvent.

Gear Oils

The lubricant refiners and chemical companies manufacture gear oils which many cyclists and mechanics regard as suitable for lubricating bike chains. Some cyclists and mechanics believed that light (low viscosity) machine oils including sewing machine oil were the most suitable.

Limits and Constraints

The limits of fluid lubrication as understood in 1990s were discussed in a paper published online, cited by Sheldon Brown and John Allen at BTI:

There are industrial chains of similar construction and loading to bike chains. When they are run in a clean oil bath, they can have service lives that corresponds to hundreds of thousands of kilometres of cycling. In contrast, five-part derailleur chains rarely give more than 20,000 kilometres of service; four-part derailleur chains rarely give more than about 10,000 kilometres of service. In dirty use, chains can wear in less than 1,000 kilometres.

Chain wear is caused by grit and poor lubrication. For bicycles, grit is often the most severe problem, as grit can pierce protective lubricant films.

Grit is a problem because the bike chain is continually dirtied by grit, dust, and mud. Even in dry conditions, the chain is exposed to a stream of dirt thrown up by the front tire. In wet conditions a greater stream is kicked up and it provides a liquid to carry the grit in to the chain and also wash out lubricant.

Road dirt can be very abrasive: consider that silicon carbide and silicon dioxide are the primary ingredients in both common sand and grinding compound, and that the other major ingredient in grinding compound is oil

Dirt sticks easily to a heavily-oiled chain. Flexing the chain then carries the dirt in to the bushings. The hard particles break through the lubricant that separates the pin from the bushing, gouging out metal and causing wear. The wear particles are also abrasive, causing more wear.

A lightly-oiled chain also attracts grit, but the light lubrication does not act as a wick to move the grit in to the bearing surfaces.

Lubricating a chain with dirt on the surface will carry the dirt in to the load bearing surfaces. Thus, for best drivetrain life and efficiency, the chain should be cleaned before it is lubricated, and the surface should be cleaned again after lubrication to remove surface oil which can attract and hold dirt.

Thorough cleaning is done with the chain off the bike, as the chain must be immersed in solvent and then flexed in order to float out the wear particles. “On-bike” chain cleaning tools lack sufficient solvent volume and soaking time to dissolve and float out the inner dirt.

Since dirt is the primary cause of chain wear, most lubricants do a good job, except those which attract and wick in grit at a high rate.

….

Some lubricants are wax in a solvent suspension. The goal is that the wax does not attract dirt, and the solvent suspension allows frequent reapplication with the chain still on the bicycle (without removing the chain and washing it). These lubricants tend to be expensive to use compared to ordinary oil or conventional waxing, because the lubricant cost is high compared to oil or wax, and because they must be reapplied frequently. However, the drivetrain tends to remain relatively clean, which is an advantage where an oiled chain otherwise gets clothes and other items dirty, and in dry conditions users often report good chain life, albeit with the inconvenience of frequent lubricant reapplication.

Some lubricants are washed off easily by water, and most lubricants are washed off easily by mud. Water serves as a good lubricant while the chain is wet, and even mud can be a slight lubricant. However, upon drying the chain may have no remaining lubrication, and the chain will typically be dirty inside as well.

Author not named, published at Pardo.net, section on Chain lubrication

Bike Drip Lubes

Wet and Dry

Dripper bottles had been used for decades as dispenser/containers for household lubricant liquids. A drip bottle is a small bottle, which can dispense a few drops or a thin stream of fluid. Aerosol and other sprays are used to dispense industrial, motorcycle and household multi-purpose solvents and lubricants.

Bike chain drip lubes – fluids – sold in smaller dripper bottles – became dominant in the 1980s. Drip lubes sold for use on bicycle chains are conventionally labelled wet or dry. Some manufacturers market “wet” and “dry” versions of fluid products. The wet/dry label does not disclose how lubricant is made. It is possible to discuss the composition of a drip lube as involving a base oil and a carrier fluid.

Drip lubes need to be periodically reapplied, on reasonably clean chains. Drip lubes degrade when water gets onto and into a chain.

Wet lubricants are marketed as useful in protecting a chain from water. But:

• Wet lubes need time to penetrate the pin/bush/roller “sleeve” and link plate spaces;
• Even higher viscosity lubes will be propelled out of those spaces;
• Wet lubes pick up dust and contamination.
• Oily lubes are not waterproof. Oil does not dissolve in water. Small droplets can become suspended in water and dissipated by water. A heavy oil will last longer than a thin oil when the bike is used in the rain or on a wet surface (the tires pick up water and spray it up onto the bike).

“Wet” lubes have higher viscosity, and greater adhesive properties – most are as viscous as motor oil or gear oil. They look and feel oily. Wet lubes, in theory, are thin enough to run and thick (viscous and adhesive) enough to stick.

Dry lubes are lower viscosity, or runny, and made with more carrier fluid, and additives. The carrier fluid reduces viscosity to enhance the the lube’s ability to flow into the chain’s spaces.

The main weaknesses of dry drip lubes are that:

• tcarrier fluid is not a lubricant. It evaporates, and lubricates poorly and temporarily;
• any lubricating oils in the blend are thin; and
• the additives in most of the dry lubes on the market are much less effective in protecting the chain from wear than advertised;
• quality control and testing are performed by the manufacturer. The user has no assurances of quality except the reputation of the “brand”;
• they are comparatively ineffective in protecting from wear – some are nearly useless. Durability or chain wear testing, which started in 2017, demonstrated that many drip lubricants, particularly dry drip lubes, are not effective to resist chain wear.

The 2013 & 2014 VeloNews articles (links in Part 4 of this series) interpeted the Friction Facts results of “dry” lubes and additives:

The lubes containing a significant amount of“carrier,” designed to evaporate quickly after application, were by far the worst of the bunch. The aerosols, which are mostly carrier, were all clumped in the last quarter, and the slowest by a large margin was White Lightning’s Epic Ride Light Lube, which is also mostly carrier.

….

Rock ‘n Roll Absolute Dry drops the oil and ups the carrier, but also ups the PTFE even further, keeping it near the top of the list. The lubes with lower PTFE or wax-to-carrier ratios always performed worse — in fact, the bottom quarter of the efficiency test is chock full of them.

The oil industry sold/sells petroleum products, including lubricants, to manufacturers who package and sell bicycle chain lubricant fluids. The relevant industries depends on sales of millions of small bottles. Manufacturers do not describe ingredients or the process with precision. Lubricant manufacturers use the languages of lubrication engineering and manufacturing in marketing their products.

The origin stories of the inventors and manufacturers of drip lubes often appear on an “About” page on a commercial web site. The stories are, to a degree, written to market a brand used by a business entity. Such stories are seldom candid stories about invention and process. The origin story of the entity including the American firm “Finish Line USA” that brands bike drip lubes as “Finish Line” asserts that the firm was founded in 1988, by an engineer who had been employed by the petroleum firm Mobil but does not explain what firms design and manufacture the products – Dupont?

The author of the article “Bicycle Chain Lubricants Explained” at BikeGremlin says:

Dry lubricants are most often made based on paraffin wax, or PTFE (“Teflon”) lubricants. Sometimes as a mixture of both. The dry lubricants are usually suspended in some sort of liquid, or solvent, that allows them to flow between the chain pins and rollers. Liquid then evaporates rather quickly, usually after 2 to 4 hours, leaving a dry (or almost completely dry) film of lubricant. So dry lubricants are still dripped, or sprayed on the chain.

Main advantage of dry lubes is that they attract less dirt – they aren’t as sticky as wet lubes. That is why they are good for dry weather use, especially if there’s lots of sand, or dust. They are also good for riding in the mud – less mud sticks to the chain, so it works better.

Main disadvantage of dry lubes is they are rather easily washed off with water. So they are not good for rainy riding conditions. Even in dry they generally need to be applied more often than most “wet” (oil based) lubes, not lasting as long. Chain needs to be clean of any dirt or other lubricants, before applying them, so they can stick to it well and prevent dirt from sticking to it. When applied, 2 to 4 hours is needed for the solvent to dry, leaving just layer of dry lubricant. If a bicycle is ridden just after applying dry lube, the lube will fall off the chain more quickly and attract more dirt – beating the purpose of using a dry lubricant in the first place. This can be impractical if a chain needs re-lubing, but one needs to go riding immediately.

Another disadvantage of dry lubricants is they can’t replentish the lubed area after they are pushed aside – they don’t flow back like wet lubes. This especially affects multi chainring (multi-speed) drivetrains where cross chaining often happens. If there’s more load on the pedals when cross-chained (like riding up a hill), the problem is more pronounced.

BikeGremlin, Bicycle Chain Lubricants Explained, 2016, updated 2021, 7. Dry Lubricants for Bicycle Chains

Some retail chemicals have solvent and lubricant properties – e.g. WD-40. WD-40 makes the retail household product WD-40 and a “dry” and “wet”bike lubes. The name and labelling imply that the bike lubes are formulated differently from household WD-40. which uses a petroleum based lubricating oil mixed with isoparaffin and other alkanes. The oil is a penetrating carrier, which disperses water repellant alkanes and removes corrosion.

Solids

Greases are made by blending petroleum lubricant oils with material that thickens the fluid into a semi-solid jelly or cream. Lithium stearate is a thickener for lithium and white lithium greases. Greases are used to lubricate bearings in bicycle components – e.g. the bottom bracket, the headset, the wheel hubs. In most applications on bicycles, greases are retained and protected from contamination and dilution by seals.

Waxes have fairly low melting points – they turn to liquid at relatively low temperatures. Some waxes have lubricant properties. It is difficult to apply grease to a roller chain in a way that properly gets lubricant into the spaces between metal surfaces inside the joints. Waxes have to be melted to a liquid to be applied to a chain – usually a chain removed from a bike and immersed in the wax. Waxes have limitations:

Some poor lubricants give surpisingly good service life. For example, solid lubricants such as wax do not move under surface tension. Thus, once load has pushed the wax out from the bushing surface, it does not flow back in, and the chain runs unlubricated. In compensation, however, dry lubricants typically do not attract dirt. Thus, a waxed chain fails due to poor lubrication, but in compensation, wear is not further aggrevated by dirt. Chain life with wax is typically worse than with oil, but is surpisingly good considering that wax is a poor lubricant, and in dry (not rainy/muddy) service, some riders report better chain life using wax than using liquid lubricants.

Author not named, published at Pardo.net, section on Chain lubrication

Paraffin Wax

The science and history, and the methods, of paraffin immersion are discussed in Bike Chains, Part 7 in this series.

Table of Contents

• Preliminary
  • Revised
  • Scope
• 4. Chain Drive
  • Industrial chain drives
  • Bushed Roller Chain
  • Material & Manufacturing
  • Bushingless Chains
  • Chain Sizes
  • Directions
  • Chain Gauges
  • Wear
    • How/Why
    • Consumables
  • Master Links
    • Importance & Origins
    • Removal and Locking

Preliminary

Revised

This is part 2 of 8 posts organized as a single article, individually published as posts on this blog. In March 2024 I began to reorganize and revise the long article. The sections are numbered for reference here and in the table of contents for each post.

Part/Post & Link	S.	Topics
1. Chain Wear		My discovery of wear Issues
	1	Safety Bicycles — History — Variety — Manufactured Industrially — Bike Brands — Shops or Stores — Mechanics
	2	Bike knowledge sources, Internet
	3	Bike Chains
2. Roller Chain	4	Chain Drive
3. Lubrication	5	Lubrication Theory
	6	Petroleum
4. Lubricants
	7	Fluid Lubricants — Motor Oil — Drip Lubes — Engineered — Wet and Dry marketing — Additives
	8	People and Projects
	9	Lubricant Efficiency Tests
	10	Wear tests – chains & lubricants
	11	Innovation 2022-24
	12	Consumers’ options
5. Cleaning	13	Cleaning
	14	Deep Cleaning with Solvents
	15	New Products
6. Durability	16	Modern Chains
	17	Durable Chain
7. Paraffin	18	Paraffin Wax
	19	Method
	20	Wax-compatible Drip Lubes
8. Learnings for Make Benefit		Assortment of Notes

The project took several months. Since then, I have edited and revised further.

Scope

This post mainly discusses the bicycle chain, an adaptation of industrial roller chain technology, usually made of steel ¹an alloy of iron and small amounts of carbon and of other metals, made by melting mineral ores in furnaces.

The chain is a part of a group of components called the drive train, which takes force from the rider’s effort pushing down on the pedals, and turns it into force driving the drive wheel to rotate which pushes the bike. The drive train includes the pedals, the crank arms, the chain wheels, the chain, the rear hub, the cassette of gear wheels on the drive wheel (normally the rear wheel) and the derailleur mechanisms. The drive train must be aligned properly, maintained, cleaned and lubricated to operate efficiently.

Chains are vulnerable to wear if and when they allow contaminated oil and water to carry microscopic abrasive particles into spaces that are supposed to be clean and lubricated. Chain wear elongates a chain, which affects performance and causes damage to other drive train components. Lack of lubrication or contamination of bearings in other drive train components (e.g. hubs, jockey pulleys) can affect performance.

A few new or modern bikes have bushed chain. Many new bikes have flexible bushingless chains. Bushingless chains may be more prone to this than bushed chains, and chains that maintain a direct chainline.

Bicycle chains can break. Usually this happens when a chain comes off the cogs – commonly during shifts with derailleurs – and is caught between components. In this situation the chain is seized, and the rider is applying force to links that are not traveling in the normal direction of travel.

4. Chain Drive

Industrial chain drives

The manufacturing and maintenance of roller chains, bicycles and lubricants was based on trial and error, experimentation and the concepts used by artisans, mechanics, engineers and riders. Chain drives were used in industrial machines before they were adopted by the bike industry late in the 19th century. Chain drives are designed for classes of machine, in some instances, for individual machines. A bicycle chain is made of links connected by pins in a continuous loop. The links must pivot rapidly at the pins as the links move in the loop.

Until modern optics and electronics provided better tools, people affected by wear had theories or mental models for what happens in a lubricated roller chain. With modern optics and electronics it is possible to view components of stationary disassembled chains. Josh Poertner of Silca Velo ²noted in the post Part 4 in this series discusses chain wear as the cause of elongation in the video on the Silca Velo YouTube channel Microscopic Magic: Save Your Chain from Wearing Out! (July 30, 2024).

Bushed Roller Chain

The links in a bicycle chain drive overlap, alternating as inner and outer. Links are made of plates and “pins”. Plates form alternating outer and inner links. Pins attached to the outside plates; the pins also fit into holes in adjacent inner links. Hollow pins made of tubular steel are common. The pins are riveted to the outer plates. The pins connect the links to adjacent links; the links pivot on the pins. On modern chains these are tubular rivets flared at each end, installed as flush rivets. Tubular “bushings” between the inner link plates keep the inner links of a bushed chain separate. The half bushings of a bushingless chain (see below) have the same effect.

Rollers were a late 19th century industrial innovation, adopted by bicycle and component builders when chain drives were adapted for bicycles. Rollers contact the cogs (teeth”) of the gears from which and to which force is transmitted. Rollers are the journals of plain bearings. (the bushing and/or the pins rotate inside the rollers. A chain drive has several dozen open plain bearings. In a bushed chain, rollers revolve on bushings around the “pins” holding the sides of the roller chain together. On a bushingless chain, the bushings are stamped shapes on the inner plates. Most bicycle drive trains from the late 1890s until the 1970s or 1980s were have been chain drives using “bushed” roller chains. Wikipedia notes:

There are … many chains that have to operate in dirty conditions,
and for size or operational reasons cannot be sealed. Examples include chains on farm equipment, bicycles, and chain saws. These chains will necessarily have relatively high rates of wear.

Many oil-based lubricants attract dirt and other particles, eventually forming an abrasive paste that will compound wear on chains. This problem can be reduced by use of a “dry” PTFE spray, which forms a solid film after application and repels both particles and moisture

Wikipedia, Roller Chain

Bushed bicycle roller chain, invented by the Swiss-English entrepreneur Hans Renold in 1880, was common on the bicycles made in the late 19th century, and on single speed and utility bicycles manufactured and sold in the first several decades of the 20th century. The invention of bush roller chain has been attibuted to others:

… the Nevoigt brothers, of the German Diamant Bicycle Company, designed the roller chain in 1898 which uses bushings.

There are two types of links alternating in the bush roller chain. The first type is inner links, having two inner plates held together by two sleeves or bushings upon which rotate two rollers. Inner links alternate with the second type, the outer links, consisting of two outer plates held together by pins passing through the bushings of the inner links. The “bushingless” roller chain is similar in operation though not in construction; instead of separate bushings or sleeves holding the inner plates together, the plate has a tube stamped into it protruding from the hole which serves the same purpose. This has the advantage of removing one step in assembly of the chain.

The roller chain design reduces friction compared to simpler designs, resulting in higher efficiency and less wear. The original power transmission chain varieties lacked rollers and bushings, with both the inner and outer plates held by pins which directly contacted the sprocket teeth; however this configuration exhibited extremely rapid wear of both the sprocket teeth, and the plates where they pivoted on the pins. This problem was partially solved by the development of bushed chains, with the pins holding the outer plates passing through bushings or sleeves connecting the inner plates. This distributed the wear over a greater area; however the teeth of the sprockets still wore more rapidly than is desirable, from the sliding friction against the bushings. The addition of rollers surrounding the bushing sleeves of the chain and provided rolling contact with the teeth of the sprockets resulting in excellent resistance to wear of both sprockets and chain as well. There is even very low friction, as long as the chain is sufficiently lubricated. Continuous, clean, lubrication of roller chains is of primary importance for efficient operation as well as correct tensioning.

Wikipedia on Roller chain, July 2021

Bushed chain is being used for some e-bikes, and some mass-produced bikes without derailleurs, as of 2021-24. On a bushed roller chain the rollers rotate on bushings around pins.

Plain bearings need lubrication, according to the experience and opinions of builders, engineers, and mechanics and riders/users. Lubrication reduces the co-efficient of friction when steel surfaces in contact with each other:

Lubrication is required for correct operation of mechanical systems such as pistons, pumps, cams, bearings, turbines, gears, roller chains, cutting tools etc. where without lubrication the pressure between the surfaces in close proximity would generate enough heat for rapid surface damage … .

Wikipedia on Lubrication

If lubrication is applied often enough, and if the chain is properly cleaned and maintained, rotational friction and chain wear are reduced. On a bicycle chain, the lubrication is directed at reducing the friction of the rotation of the rollers on the bushings, and the bushing on the pins. When the lubrication fails, the rotation fails, and the direction of friction become intermittently linear which produces audible squeaks as the chain metal of the bushing and the pin wears.

“Factory lubrication” of bike chains by the chain manufacturers seems to have become a common practice when bushed roller chains were common.

Parts 3 and 4 this series, on lubrication, lubricants, and testing, will discuss the researched and tested fact that oil based lubricants work by creating a film across metal surfaces, and how lubricants behave when contaminated with water and dirt.

Material & Manufacturing

Chain link plates for modern bike chains are punched out of steel sheet metal made with carbon steel. Steel is an alloy of iron, carbon, and other elements. Carbon steel is more susceptible to oxidation (rust), corrosion and wear than other steels. Chromium makes steel harder and more resistant to oxidation and wear. Alloys harder or more resistant to corrosion than carbon steel would cost more and would require retooling by the chain manufacturers. On some chains link plates and other chain parts are plated with metal less susceptible to corrosion, or case hardened.

Adam Kerin of Zero Friction Cycling provides ³mentioned and discussed in Part # 4 in this series an overview of materials at pp. 9-11 of his chain longevity testing brief:

The most common hardness ratings are Rockwell D and Vickers.

… the Vickers hardness test is generally regarded as the most suitable. Mild steel/stainless steel will typically have a Vickers hardness rating of around 150 to 200. Quality hardened steel will be 200 to 400, or even 500, and the highest level tool steels / high speed steels can be up to 700.

However – the harder you make steel, the less ductile and more brittle it becomes. Steel can be made with very high “toughness” – combination of hardness and ductility – but this is very expensive requiring alloying with multiple other metals plus quite exacting heating/cooling cycles. For bicycle chains … different manufacturers use a different level or grade of steel. Campagnolo for instance claim their chains are made of “special steel”. What grade of steel is used is unlikely to be advertised or even disclosed by manufacturers. But in summary for bicycle chains, you can expect the steel will be hardened for wear longevity but there is limit as to how hard they can make this steel without the chain becoming too brittle and snapping on the first poor shift – especially the more economical grade of steel that is used.

Adam Kerin, Zero Friction Cycling site, Chain longevity testing brief, 2018

There is no industry standard for the necessary hardness and tensile strength of the steel. Chain manufacturers order sheet steel by thickness – they trust the steel mills to supply steel that meets the chain maker’s specified standards. Chain manufacturers will market some chains as having been hardened more and better, or coated. Some chains are better than others. Bike manufacturers and bike shops disclose the name of the chain manufacturer; a high value chain may be a marketing point. Even cheap chains work for hundreds of hours.

Modern chains are as light as feasible. Some materials and manufacturing methods make some chains last longer than others in a perceptible way. Some of the issues will be discussed in Part 6 in this series, on durability

Bicycle manufacturers acquire chains (supplied with new bikes) from specialty manufacturers including Renold, Campagnolo, Rohloff, Wipperman, Shimano, YBN, KMC, SRAM and others. Some chains are still manufactured by German, French, English and Italian firms. A few chains are made in Japan. Bike chain manufacturing in 2022 (and 2023 and 2024) is largely an Asian industry. The manufacturers all make chains out of the same raw stocks, but have different suppliers, machinery and workforces. Some chain manufacturers subcontract to each other. A few chains are made in Europe and the US. (The packages of chain sold by the US brand SRAM indicates those chains are manufactured, or at least assembled and packaged, in Portugal).

The Japanese firm Shimano is a dominant force in manufacturing bicycle components, including cranks, derailleurs, and chains. It outsources a portion of production of its branded chains to manufacturers in Asia, e.g. KMC of Taiwan or YBN, a Taiwanese firm that makes chains in a plant in Vietnam. SRAM brand chains are manufactured in Portugal. Many European manufacturers have subcontracted to Asian firms or built Asian plants.As of the early years of the 2020s, most chains are manufactured in Asia.

Many chains are made in Taiwan, the People’s Republic of China and other Asian countries with steel, and other industrial supplies and with manufacturing capabilities. The steel in chains machined in Asia will normally have been sourced from Asian foundries – it will have been smelted and forged from iron ore and carbon, rather than from recycled steel. Pins are steel too. The pins are fabricated from steel stock according to the methods used by manufacturers. The steel mills decide how to forge, roll and process the steel. The chain manufacturer can choose the thickness and some of the performance characteristics of the steel. The options depend on what the steel manufacturers are selling, and price. The shortage or unavailability of chains for purchase in 2020. 2021 and 2022 was attributed to delays in production and transportation of materials.

Bushingless Chains

The bushingless chain was developed by Sachs under the Sedis brand and introduced in 1981. It was adopted by SRAM, which was a mountain bike component manufacturer at that time. The innovation was widely adopted by other designers and manufacturers:

More recently, the “bushingless roller chain” design has superseded the bushed chain. This design incorporates the bearing surface of the bushing into the inner side plate, with each plate creating half of the bushing. This reduces the number of parts needed to assemble the chain and reduces cost. The chain is also more flexible sideways, which is needed for modern derailleur gearing, because the chainline is not always straight in all gear selections.

Wikipedia article on Bicycle Chain

The holes in outer link plates are smaller than the holes in inner link plates. The holes in inner link plates are punched to create the protruding shoulders which serve as partial or “half” bushings. The lateral flexibility of chains (necessary for shifting to different gear wheels or cogs) was engineered by swaging (shaping the pins into barrels rather than perfect cylinders).

The side plates of the inner links are formed into half bushings or shoulders. The roller rides on the half bushings. The pins go through holes in the outer side plates and the half bushings and hold the links together. The outer plates overlap and turn against the inner plates. The plates turn on the pins where the pins go through the plates. My photo of an outer and inner link (left over after I had shortened my new bushingless SRAM chain for installation) shows these features. The hollow pins used in this chain connect the outer links – an outer link on the left. The pin on the left is still partially displaced by the chain breaker tool (there is no roller on that pin – the roller stayed in inner link which was used to close the chain with a master link). The inner link on the right has been pried open to release its roller and show the bevels. The (small) magnification of my smart phone camera shows what the surface, which appears to be perfectly smooth and shiny, are actually rougher. The roughness does not affect the travel of the chain over the cogs. Lubrication is supposed to affect the articulation of the plates, rollers and pins at the ends of the links.

Modern bushingless chain is more vulnerable to wear than other designs:

The inner side plates of a bushingless chain are three-dimensional. Instead of having a simple hole at each end with a bushing pressed through it, each inner side plate hole has a protruding shoulder that amounts to half of a bushing. Since the side plates have an inside and an outside determined by the existence of the shoulders, they can also have bevels on the inside edges without further complicating the manufacturing process. These bevels permit the chain to run more smoothly when it is not perfectly lined up with the sprocket than a conventional chain with flat inner plates. They probably also improve shifting performance.

Since the “bushing” of a bushingless chain is made up of two halves that don’t connect directly with each other, this type of chain is more flexible sideways than a conventional chain. This is because the two halves of the “bushing” have a bit of “wiggle room” with respect to each other.

BTI (Sheldon Brown site), Chain Maintenance

The bushingless chain is more vulnerable to some kinds of failure. Sheldon Brown and John Allen said:

The lightweight chain of a bicycle with derailleur gears can snap (or rather, come apart at the side-plates, since it is normal for the “riveting” to fail first) because the pins inside are not cylindrical, they are barrel-shaped. Contact between the pin and the bushing is not the regular line, but a point which allows the chain’s pins to work its way through the bushing, and finally the roller, ultimately causing the chain to snap. This form of construction is necessary because the gear-changing action of this form of transmission requires the chain to both bend sideways and to twist, but this can occur with the flexibility of such a narrow chain and relatively large free lengths on a bicycle.

Chain failure is much less of a problem on hub-geared systems (e.g. Bendix 2-speed, Sturmey-Archer AW) since the parallel pins have a much bigger wearing surface in contact with the bush. The hub-gear system also allows complete enclosure, a great aid to lubrication and protection from grit.

Wikipedia on Roller chain, July 2021

Bushingless chains have tiny internal voids around the middles of pins where the half rollers on each side end. Lubricants applied to the outside of a bushingless chain flow differently than lubricants applied to bushed chains. The lateral flexibility of bushingless chains, and the effects of lateral movement on fluid on the chain appear in a video on YouTube posted in the Silca Velo channel ⁴See Part 4 for information on Silca Velo in April 2024 called Stop Wasting Your CHAIN LUBE! Know the BEST Way to Apply It. The wiggling action is shown in a segment about 8 minutes long, starting about 7 minutes after the beginning.

Chain Sizes

Pitch is the length of any link, outer or inner; pitch (length) is the distance between pins, measured from the centers of pins. It can be expressed as an ANSI number, or a fraction of an inch, or in millimeters. See:

• Wikipedia, Bicycle Chain: Sizes;
• Wikipedia, Roller Chain: Chain Standards;
• Bicycle Technical Information, Glossary, Chain/Sprocket pitch;
• Bike Radar, Bicycle chains explained;
• Bike Gremlin, Bicycle Drive Chain Standard Dimensions.

The standard pitch for modern bicycle chains is ANSI 40 (designating 4/8 inch) = 1/2 inch = 12.7 mm. On the assumption that all links are counted (as opposed to counting pairs of inner and outer links) , a chain will normally be more than 100 links long. A road chain may have 108 links or more. A gravel or mountain bike chain will be longer. A chain for a compact road crankset with a 46 tooth large ring and a cassette with a 36 tooth large cog will be about 112 or 114 links long. Chain length depends on the length of the chain stays and the diameters of the largest chain rings and cogs.

The chain must be long enough to go around the largest front ring, around the derailleur pulleys, and around the largest cog on the cassette. The derailleur must be left in a position to shift the chain effectively. On measuring a chain, see:

• BTI (Sheldon Brown site): (Rear) Derailer Adjustment; Chain Length;
• YouTube video Alex Ramon at BikeRide.com, 2019, How to Calculate chain length;
• YouTube video, Global Cycling Network channel, 2016, How To Calculate The Correct Chain Length (Road Bike)
• YouTube video, Park Tool channel, How to Size a Bicycle Chain.

The BTI method of sizing a chain is to break a chain (remove links with a chain breaker tool) to fit the largest rings. A chain breaker tool pushes pins (the rivets that hold the chain together) out. Another key measurement considers how the chain is tensioned when the chain is on the smallest gear wheels on cassette of drive wheel. This makes sure the chain does not fold and rub on itself.

The rear derailleur, which is found on almost all geared bicycles, imposes a total system limit, which affects the length of the chain. Adam Kerin of Zero Friction Cycling discusses the system limit in his video, on the ZFC YouTube channel March, 2023, “When 1X goes wrong“. The system limit can be calculated as the sum of the number of teeth on the front ring (or the largest front ring) and the largest cog on the drive wheel (usually the rear wheel) cassette. The system limit varies. Rear derailleurs for road (and gravel) bikes have a limit of about 84 teeth. If the front ring is 50 teeth, the largest rear cog must be under 34 teeth. “Compact” front rings on many road and gravel bikes are from 48 teeth, down to 36 teeth. The system limit for some rear derailleurs for mountain bikes is about 90 teeth – they will run a 45 tooth cog with a front ring of 45 teeth or less.

A 108 link chain is 1371.6 mm long; elongation by .5% is a fraction more than 6.8 mm. A drop-in chain checker gauge measuring about 170 to 199 mm. is used to indicate if the elongation in a span exceeds .5%. In a span of 1/8 of the length of chain, the gauge has to detect the difference in that span to a tolerance of .5 mm.

Pitch is standardized. The width of chain links varies. It is generally proportional to the number of cogs on the cassette on the drive wheel. The spaces between cogs in modern systems are so narrow that shifting is only feasible carefully adjusted rear derailleurs. Bike component makers have claimed the benefit of indexed shifters which are the components on almost all new bikes, and bikes made in the last 40 years. (Some riders still prefer friction shifters).

Cleaning the paste of lube and dirt out from between cogs requires narrow tools. Older tools for cleaning a cassette may not fit. It isn’t necessary to resort to butchers twine to floss debris out of the spaces. The changing number of cogs has made wider tools obsolete.

Bicycle chains for derailleur systems with 11 or 12 cogs on the cassette, measured by internal or external width:

• internal – 11/128 inches = 2.2 mm;
• external
  • 11 cog – 7/32 inches; 5.5 to 5.62 mm;
  • 12 cog – 13/64 inches = 5.3 mm.

Bike manufacturers buy chains and install the chains on new bikes. Even where the bike manufacturer uses a Shimano or other brand name drive train component set (crank arms, chain rings, derailleurs, rear cassette), the chain may be by another manufacturer. Bike manufacturers have begun to change their “current” models almost annually.

Most chains have standard dimensions. Some chains have specific features and limitations, requiring that the gears have specific dimensions and features. Component manufacturers and bike shops may suggest a chain should be made by the same brand as the rest of the drive train. This seems to be a myth.

Directions

Some chains are supposed to be installed to run in one direction. The “flat” side of a SRAM flat top chain is on the outside of the chain as it passes over the the teeth of the cogwheels of the cassette and of the chainwheel.

If a chain’s links are etched or stamped on one side, that side should be installed so that the arrow or text is visible and/or the arrow points forward as the link goes forward on the top side of the loop on the side of the bike from which the chain is accessible – the side:

• with the cassette and the chain rings and
• the chain passes over the chainstay moving from the driving wheel to the chainwheel.

Many chains are not etched or stamped. Some mechanics maintain that there are other ways that can determine which side of the chain should face the persons installing a chain.

Chain Gauges

The bike chain and bike tool industries developed tools to measure wear, called chain gauges (or chain checkers). Articles by the Australian cycling tech writer Dave Rome on checking for wear, based on discussions with Adam Kerin of Zero Friction Cycling (“ZFC”), and on other sources):

• Dave Rome at Bike Radar, 2016, How to know when it’s time to replace your bicycle chain;
• Dave Rome at CyclingTips, August 2019 How to check for chain wear: The easy way, the best way, and why (no longer on line – Outside has dropped it as of late 2023 and early 2024) The ZFC measurement methods were explained in this article). (Dave Rome left CyclingTips in 2022. He contributes to the EscapeCollective media as of 2023 and early 2024).

There are videos on chain gauges and other chain tools, and online instructions on using them. There are several inexpensive drop-in checkers by previously unknown vendors for sale online; several claim to be laser cut. Adam Kerin of ZFC has published articles and videos on checking chains. There are videos and podcasts of his interviews. Adam Kerin’s advice on chain gauges, and some of his related advice on maintaining chains, can be summarized:

• get a simple drop-in gauge;
• make sure it is an accurate one;
• know how to use your chain checker and use it regularly;
• lubricate the chain regularly and clean it frequently. The cleaning will depend on conditions and which lubricant has been used;
• consider checking chains on long rides and the possibility of replacement along the route;

For his ZFC chain wear (elongation) tests, discussed in Part 4, Adam Kerin used the (expensive) KMC digital caliper chain checker. Adam Kerin says a drop-in metal gauge is a sufficient tool for the rider/home mechanic, but”

• cautions that drop-in gauges must be precisely made in video episode 5 of the ZFC YouTube series;
• recommended the Shimano TL-CN42 because it is cut to the exact tolerance, and reliably free of manufacturing errors. The tool was not on Shimano’s US sites in early 2022 (or in 2023). Some dealers advertised at that time. It was out of stock at ZFC as of February, March and April 2022 but in stock at ZFC in late 2023 and early 2024. It was selling for nearly $90 (Canadian) on Amazon at times 2023-24.
• said that many drop-in gauges are cast and finished poorly, and do not measure the short span to the tolerance required.

In his YouTube Video of February 2, 2024 on his ZFC channel, he discussed the drop in gauges which were known to accurate enough, without any reports of varying measurements between individual products of the same model.

He published his findings in a chain wear checker table. He said a few of the drop in gauges were accurate:

• Shimano TL-CN42
• Park Tools CC-4
• Pedro’s
• Abbey Bike Tools LL Chain Wear Tool ⁵Abbey Tools in advertising this tool in 2024 says “Most chain wear tools currently on the market are laser cut metal. This is a pretty cool process that’s great for making sheet metal parts, problem is the accuracy of this process isn’t great at +/-.010″ (.254mm). If you add the error of the tool itself to the roller variable it’s possible to double the error of the tool”.

Adam Kerin did not recommend the KMC digital caliper chain checker, on the basis that it is not a drop-in gauge, and is not inexpensive.

Dave Rome, the CyclingTips tech editor and correspondent in Australia described the subject of measuring chain wear as “murky” on the Ask the Mechanic segment in the NerdAlert podcast episode recorded February 21, 2022 ⁶no longer on line – owner of the Outside family of content unpublished it as of late 2023. He noted the Park Tool CC-2 gauge is capable of some precision but is vulnerable to bending of the pins affecting the accuracy of measurement. He thought the Park Tool CC-3.2 drop-in gauge was reliable for most chains except some SRAM 12 speed chains. But Adam Kerin had reservations about it.

I had a ParkTool CC-3.2. It sold for about $12 US from US online bicycle supply stores (and for $18 or $35 from vendors in the Amazon market jungle) in 2022. I had no context or background on how often to use this or any chain checker. In 2022, I was wondering if it was accurate. I had a new chain available. My kludge to confirm my gauge was good enough: I tried it on a new chain (making sure the chain was taut). The tip did not drop in, and the tip did not pass the midline of the pin inside the roller the tip was touching.

The CC-3.2 measures total elongation – it does not “isolate” the rollers. It has hooks at one end, on each side, to fit against a roller. One side is machined to detect .75% wear. One side is machined to detect .50% wear in chains for 11 and 12 speed cassettes.

Side	Chain	Distance Hook to Tip
.75%	7-8-9-10 speed	≪172 mm
.50%	11-12 speed	≅171 mm

The manufacturer’s instructions recommend dropping a hook end into an inside link. The user should ensure the chain is taut and the hook is held against the roller. Park Tool says the device can be used at the top or the bottom of the loop (between chain ring and rear cog) – the derailleur spring should be pushing the chain taut at the bottom. This gauge spans nearly 14 pins; the tip can touch or fall short of the 14th roller. A chain is elongated when the tip falls does not rest on the roller at the other end (it is falling short) and drops into the inside of the link. The Park Tool CC-3.2 chain gauge measures a span just over 170 mm. to indicate if the elongation in a span exceeds .50%. In a span of 1/8 of the length of the chain the gauge has to detect the difference to a tolerance of .5 mm.

I started to use a Park Tool CC-4 and the Abbey Tools device in 2024.

Wear

How/Why

Open bearings are vulnerable to contamination. Roller chains have to be cleaned and re-lubricated. Even well maintained roller bearings will wear. A metal roller chain wears. This makes chain get longer. The plates and pins do not stretch, compress or deform.

The cause of elongation is believed by some riders to be “stretching” of the chain. Josh Poertner of Silca Velo 7noted in Part 4 of this series discusses wear as the cause of elongation, using a digital microscope device, to produce the video Microscopic Magic: Save Your Chain from Wearing Out! (July 30, 2024) to look at a badly worn chain (a SRAM PC 1051)

Some count 1 link as a set of 1 inner half-link and 1 outer half-link; others count all links.

Microscopic wear on individual links adds up. One of the consequences of wear is elongation. An elongated chain fails to fit the gears (cog wheels) – the chain wheel and the toothed wheel on the cassette on the rear wheel, cause wear on the gears.

With modern 11 and 12 speed bushingless chains, elongation of .5% (half of one percent) of the length of the chain leads to replacement. A chain may show almost no elongation wear for several hundred Km., and then wear rapidly. Chain wear is not linear.

Consumables

Bike, component and chain manufacturers expect consumers to accept chains which have limited durability. Purchasers of new bikes may have to replace or upgrade the chain frequently. The bike, component and chain manufacturing industries expect bike chains have have a short service life, which is defined as a short mean time before failure. Failure can mean breaking but it usually means elongation by wear.

They sell bikes with chains they expect to fail within a few thousand Km. of use.Whether bike and component manufacturers follow a strategy of planned obsolescence might be debated. The inspection and replacement methods used for industrial machines and motor vehicles – e.g. days or hours of operation or distance – do not work for most bikes and chains.

Few modern chains are good for more than a few thousand Km before becoming measurably worn – durability varies with chain material, riding conditions, lubrication and cleaning practices. Bike manufacturers trust the chain manufacturers. Consumers trust the manufacturers and the market.

Master Links

Importance & Origins

Master links, devices that replace a single outer link, were noted in the BTI (Sheldon Brown) glossary. Master links for chains for single speed drive train chains were once rare. A few custom metal fabricators made and sold universal master links for derailleur shifting chains by any manufacturer on the market by the 1990’s – e.g. the Craig Super Link. Before master links, removing a chain involved pushing a pin out with a chain breaker tool, Installing a chain involve peening⁸some chainbreaker tools have peening anvils, and are capable a pin with a tool.

The master link makes removing a chain for cleaning, maintenance and replacement easier. Chain manufacturers developed proprietary master links for some of their chains. One of Shimano’s systems secured the master link with a special pin. Some manufacturers had three part links – 2 link plates and a spring plate to slide over the pins and clip the links. Connex/Wipperman still sells this kind of link. A few other universal links came on the market. The manufacturers were small or fabricated the devices in limited quantities. Some non-proprietary or univeral links are on market or in use. Some master links can be used by any chain of a given size, by any manufacturer. Master links can be used on chains are built to the standards of the pitch and width for compatibility with the number of cogs on the cassette on the drive wheel (i.e. links are machine to work on “11 speed” chains exclusively). Some manufacturers market links as compatible with other manufacturers’ chains of the same size – e.g. YBN. Others insist on branded links for their branded chains.

Many master links involve two parts. Each part is one link plate with one solid pin riveted to the plate. The pins are machined with a groove or slot at the free end that fits into a machined slot and hole in the opposite plate. Connex Wipperman uses curved slots for some models, and straight slots for others. Many manufacturers have one straight slot model in each size. For instance see the YBN product. Two part systems depend on getting both pins into the opposite slots and locking the link. Two part master links are made by Shimano, SRAM, YBN, KMC and others. The manufacturers’ names for their master links may cause some confusion.

Most two part master links are sold as “single use”. YBN’s 2 part master links, labelled Safe Sections and QRS (Quick Release-Safety) are sold by YBN and by vendors who (re)sell them as safe for five uses.

Josh Poertner, of Silca Velo shows how two part master links work in the June 26, 2024 Silca Velo video Chain QUICK LINKS: Are they keeping you from waxing?

Removal and Locking

Riders commonly reuse master links. Some users only remove a master link to replace a chain.

A master link may fail. The finely machined slots are vulnerable to microscopic, nearly invisible wear, fatigue and stress. The risk of the failure is real.Often failure is caused by improper installation. It is sometimes caused by wear of the finely machined slots in the pins and plates – which can be caused by removing and locking the link too often or damaging the locking slots.

Needle nosed pliers are too wide to close or open a master link on modern narrow chains. There are special pliers that can open and/or lock a link. Locking the master link without a locking tool depends getting the pins into the slots, holding the bike steady and stepping on a pedal.

A master link can be removed with master link pliers, like the Park Tool MLP-1.2, which is sold in bike shops and online for about $17 to $25 US. The Park Tool pliers can be used to lock or remove a master link, and can fit a chain as narrow as a 12 speed chain. There are other master link pliers on the market. Most are bulky or heavy enough that they will not fit in a seat pack. Light compact travel tools are available. Some of the compact tools store replacement links. The parts of a master link can be easily lost.

Master links are durable but vulnerable to wear and stress in places – the slots that hold and lock the pins. Immersive waxing requires removing the chain at intervals of a few hundred Km.

A user trying to remove a link from a chain on a bike will need to address the tension in the chain caused by the rear derailleur spring. When the link is released and pins are clear of the slots, the chain can snap, flinging the parts into space. Putting the chain on the smallest rear cog and the smallest chain ring (in 2x or 3x systems) reduces the tension. The user has to keep a grip on the chain which may be dirty and greasy. Some chain breaker tools have a wire accessory – the thickness of spoke – bent just less than 90 degrees at each end. This can be detached from the tool body and slipped over rollers of links beyond the master link. Some users make such an item with a piece of scrap spoke (a coat hanger may fit into outer plate links but not inner plate links in 10 speed or narrower chains). Some will shift to the smallest chain wheel and the smallest cogwheel on the cassette and manual take the chain off the chainwheel to remove the tension.