Bike Chains 1 – Roller Chain Drive

Table of Contents

Chain Wear

I had less than 2,000 Km. since purchase on my (Cannondale Topstone) gravel bike in April 2021. I had been washing the KMC X11 (11 speed) chain in a Park Tools CM-5.3 Cyclone chain cleaner and applying new lube every two or three weeks. Last year I used up some old lubricant and began to use Muc-Off’s “retail” products (as opposed more expensive “race” products). There was some wear visible on the outside of some plates. The Park Tool CC-3.2 chain checker was reading that the chain should be replaced. I located a new SRAM PC 1170 chain and a supply of SRAM Powerlinks (SRAM’s proprietary master links). This was fortunate, in view of the effects of the Covid-19 pandemic on manufacturing and shipping of bicycle components.

Searching the Web

Limitations

I am not a mechanic. I have done basic home maintenance on my bikes. There are resources on the Web. YouTube contains many videos explaining and illustrating many processes.

Searching the web or the internet for information about bicycle chain cleaning, maintenance and lubrication using a search engine is a flawed way of learning about many subjects because searches generate long lists of useless links to uninformative sites and pages:

  • Many pages are direct advertisements for products;
  • Many pages make improbable claims about products;
  • Many pages appear to compare or review products but usually:
    • It is not possible to find out if the author or publisher has been paid or influenced;
    • The comparisons are between the products which the author or publisher mentions i.e. limited to as to what is available at a time at a location or in an area;
    • The testing, if any, is not scientific and does not assess the actual conditions of use;
  • Many pages are often catalogues of methods, sometimes overly broad;
  • Most user pages and posts are short, and reflect personal experience in conditions that are not clearly explained.

There is no “wise crowd”; the crowd does not assess facts the same way or respond to the same question. Some of the user comments in forums reflects mechanical experience, but the amount of experience with the products is not clear. Some user comments reflect frustration that the bike industry keeps selling more expensive new bikes and components while bikes are harder to maintain without tools, supplies and knowledge There is little useful information about effective lubrication products and procedure.

Web contributors include industry and bike shop personnel, mechanics, journalists and riders. Russ Roca at Path Less Pedalled has published a great deal of useful material; his interview with Josh Poertner of Silca, Your Tires are Lying to You! in January 2020 was accurate and informative, an example of using engineering and science to cut the fog. In July 2021 he published Why I Started Cleaning My Chain and Why YOU Should Too!. He mentioned the scarcity of bike chains and other repair parts during the Covid-19 pandemic, and pointed to this as a reason for cyclists to take proper care of their chains. He was not the only person publishing on the web to address the new constraints on maintenance and repair caused by the pandemic. Russ Roca’s explanation of cleaning, however, added little to several articles online (below in Part 3), and nothing to my understanding of lubrication.

Resources

Wikipedia is careful and reasonably fulsome. The Wikipedia page for bicycle chain says that cleaning and lubrication are important, complicated and controversial:

How best to lubricate a bicycle chain is a commonly debated question among cyclists. Liquid lubricants penetrate to the inside of the links and are not easily displaced, but quickly attract dirt. “Dry” lubricants, often containing wax or Teflon, are transported by an evaporating solvent, and stay cleaner in use. The cardinal rule for long chain life is never to lubricate a dirty chain, as this washes abrasive particles into the rollers. Chains should be cleaned before lubrication. The chain should be wiped dry after the lubricant has had enough time to penetrate the links. An alternative approach is to change the (relatively cheap) chain very frequently; then proper care is less important. Some utility bicycles have fully enclosing chain guards, which virtually eliminate chain wear and maintenance. On recumbent bicycles the chain is often run through tubes to prevent it from picking up dirt, and to keep the cyclist’s leg free from oil and dirt.

Wikipedia (October 2021) on Bicycle Chain

Sheldon Brown and John Allen are good, in spite of a few comments that do not hold up (for instance that factory grease is better than better than nothing). They have an entry on chain in the bicycle glossary on the Sheldon Brown bicycle site, a major article on chain maintenance, and several other articles on chains. This comment on how riders adhere to beliefs about chain maintenance rings true:

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.


Brown & Allen, Sheldon Brown site, Chain Maintenance

Josh Poertner and other broadcasters hired, employed or sponsored by Silca did

  • a video on chains and friction in June 2020 in the Marginal Gains series on the Silca Velo channel YouTube channel called Chain Friction Explained!;
  • a Marginal Gains podcast in November 2020 “Lubes & Chains & Marginal Gains“;
  • several podcasts interviewing people who test lubes and chains; and
  • several podcasts and videos on cleaning chains and applying lubricant.

Cycling Tips did a useful podcast in its Nerd Alert series in August 2021 on chain lube testing. Zero Friction Cycling has started testing chain for wear and reviewing chains.

Bike chain drives

Roller chains

Bicycle drive trains are roller chains, or chain drives. Chain drives were used in industrial machines for decades before they were adopted by the bike industry at the end of the 19th century. In industry, the bushed or bush roller chain was common, because it was more durable. On a bushed roller chain the rollers contact and rotate on bushings around pins. The pins attach the plates on the outer links; the bushings fit between the inner link plates, The rollers fit around the 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

A metal roller chain does not stretch. It wears, which makes it get longer – a longer chain fails to fit the cogs and fails. A roller chain has a few dozen open plain bearings which need lubrication, according to the opinions of builders, engineer and mechanics for engineering reasons. Lubrication reduces the co-efficient of friction when steel surfaces in contact with each other move.

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

… many chains … 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, particularly when the operators are prepared to accept more friction, less efficiency, more noise and more frequent replacement as they neglect lubrication and adjustment.

Many oil-based lubricants attract dirt and other particles, eventually forming an abrasive paste that will compound wear on chains. …

Wikipedia on Roller chain, July 2021

The manufacturing and use of roller chains, bicycles and lubricants was based on trial and error, experimentation and the concepts and models used by artisans and engineers. In industry, oilers – specialized employees lubricated open bearings in various devices in the 18th, 19th and 20th centurie. The industrial view, historically, was that generous lubrication was better.

Industry relied on vegetable oils and animal fats (including by-products of whaling) until the beginning of industrial refining of petroleum in the 1840s and 1850s. Engineers refined petroleum before late 19th century scientists articulated the periodic table of elements or began to work out the principles of organic chemistry and chemical engineering. The modern view is that petroleum is a soup of 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. Most modern lubricants are made of refined petroleum products.

American lubrication engineers formed a learned society in 1944. Lubrication became an interdisciplinary specialization now known as tribology. It is not molecular nanotech but it is nanotechnology that studies and explains the interactions of nanomaterials on moving surfaces. The name of the American society of Tribologists and Lubrication Engineers was modified to acknowledge the change in professional thinking. Tribology is not a regulated profession – there is no law or process to prevent any person, regardless of knowledge or skill, calling themself a tribologist.

Safety bicycles

The modern bicycle evolved from the safety bicycle, an industrial product which relied on late 19th century innovations in material and manufacturing. The high mount bicycles (including penny-farthings) in use in the 1860’s and 1870’s had pedals and cranks that directly drove a large drive wheel. A drive chain lets a rider seated between the wheels over the center line power a geared drive wheel. The safety bicycle has been incrementally redesigned. An article in Bicycle Times in 2017 is illustated with images of 25 influential bicyle designs. The article does not include samples of the designs that have dominated the bicycle markets in the recent decades, or cargo bikes or e-bikes.

The majority of bicycles in Europe and North America – indeed world wide – in the first six decades of the 20th century were single speed utility bicycles. These bicycles were popular in Europe and North America until the 1970s. Bike manufacturing in Asia up to the 1970s was mainly devoted such bicycles for riders in Asia. The Chinese government began to built the Flying Pigeon bicycle in 1950. 75 million were made and sold. David Edgerton counted bicycles as an old technology that was adapted in Asia in his 2007 book The Shock of the Old: Technology in Global History Since 1900. The ownership of bicycles increased in China as production increased in the 1970s. Part of the Asian production was commissioned by bike manufacturers elsewhere in the world. Asian manufacturers became proficient in producing new bicycles and components for the world market. Shifts in consumer tastes in Europe and North America spread to other parts of the world. Many Asian consumers began to have sufficient resources to afford and favour foreign designed bikes. Chinese consumers purchase brand name bicycles popular in other parts of the world.

After experimentation, the bike industry began to use bushed roller chain on most bicycles. The roller chain has been a constant. Bicycle roller chains have been made of steel since they were introduced, as far as I can tell. Steel had the tensile strength for the purpose, and could be produced with relatively smooth surfaces. The parts that connect the links are made with tight tolerances, for transmission of force. There are microscopic gaps between pins and rollers and/or bushings, which allow the links to pivot to rotate on the chain rings and the cogs of the driving wheel transmission apparatus. The basics of roller chain are alternating links, the ability to bend at the ends of links, and rollers:

The ideal or most efficient line from the chain wheel to the cog on drive wheel for single speed bicycles was parallel to the bicycle. In Europe and North America, riders and riding favoured systems that allowed the rider to shift gears. Road racing the development of derailleurs to shift the chain onto other gears – and a flexible chain that could operate at a slight deviation from a straight chainline. Chains are designed to flex to displace far enough to change gears when pushed by the upper pulley (jockey wheel) of a derailleur. Innovators altered the design of chains to get lighter, more efficient chains. At the end of the 1970s, a road bike might have 5 or even 6 cogs on a rear cassette. Mountain bikes adopted derailleurs, flexing roller chain, and other technology from road racing. Mountain biking became competitive and mountain bikes became popular. For a time, drive train components became specialized. Some innovations were made in road chains or mountain bike chains and came to become common or dominant after time.

The drive chain has to run over and under a chain stay – usually on the right side of the bike. The chain stays are welded or attached to the bottom of seat tube near the bottom bracket shell, and to the seat stays, making the chain stayone side of a closed triangle. Before the use of master links, it was necessary to use a tool to displace a pin to “break” and remove the chain. It was not a common practice before the development of master links. Master links were noted by Sheldon Brown, but the history of the master link has been hard to find. Master links for chains for single speed driver train chains at someCustom metal fabricators had universal (for chains by any manufacturer) master links for derailleur shifting chains on the market by the 1990’s – e.g. the Craig Super Link. This kind of initiative was more common to the mountain bike community. A few other universal links came on the market. The manufacturers were small or fabricated the devices in limited quantities. Newer thinner chains came on the market. Chain manufacturers developed proprietary links with each new chain. Some of the non-proprietary univeral links are on market or in use. Even with master links, removing a chain is a complicated operation. Chain manufacturers and bicycle shops discourage it.

Some parts of the history of the bicycle roller chain supply chain have been discussed by historians of sport or commerce. As of the early years of the 2020s, most chains are manufactured in Asia. Shimano of Japan became a dominant force in manufacturing components. It outsources a large portion of production of Shimano branded chain to manufacterers else in Asia, e.g. KMC of Taiwan.

For much of the 20th century, bike chains were lubricated with motor oil – a refined product made from crude petroleum. Motor oil was and is a specialized product to lubricate parts of an internal combustion engine. At the end of the 19th century, industry settled on the internal combustion engine was the device that could be used to power passenger cars, motorcycles, transport trucks, farm machinery and industrial machines. In this context, the development of the safety bicycle seems less consequential.

Bushed and bushingless

The Wikipedia article describes the bushed chain. Bushed chain has become less common but is being revived for e-bikes. The article also mentions the innovation of bushingless chain :

… the Nevoigt brothers, of the German Diamant Bicycle Company, designed the roller chain in 1898 which uses bushings. 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 bushingless chain was developed by Sachs under the Sedis brand and introduced in 1981. It was adopted by SRAM, which initially had been a mountain bike compoenent manufacturer, and became popular. The side plates of the inner links are formed into half bushings or shoulders. The roller rides on these half bushings. The pins go through holes in the outer side plates and the half bushings and hold the links together. The outer plates 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.

Sheldon Brown and John Allen said:

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.

The pins are hollow tubes on many chains. The flexibility of chains was engineered by swaging (shaping the pins into barrels rather than perfect cylinders):

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

Modern Chains

Alternatives

There are few choices for drive systems without chains and derailleur shifting. Roller chains are being used on cargo bikes and e-bikes. The Sturmey-Archer enclosed gearing (enclosed inside the hub) system used on Raleigh bicycles was popular. There is continuing talk of innovation in transmissions or drive systems- see this article at Bike Radar. In the mean time, riders have to maintain the bikes we have and use.

E-bikes

Many bike manufacturers use regular bike chains and rear derailleurs on e-bikes. Some manufacturers use purpose-designed e-bike chains. E-bike chains may be bushed and wider than popular chains for road bikes. Some chain manufacturers claim that 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.

Light chains and replacement

In 2021, most modern bikes, other than e-bikes, on the market (in Canada and the USA) have rear wheel cog cassettes with 11 or 12 cogs. Chains are thinner and lighter than chains manufacturered earlier. Modern chains are assumed to have short lives – they have to be replaced even if they chains have been cleaned and lubricated. Chains, like other retail sporting products, are sold at different prices which may signify gradations in quality. Quality does not mean durability or freedom from lubrication and maintenance tasks.

Lubration – basic

Grease and Oils

Fluid lubricants can be applied fairly easily to the joints between links of bike chains. It is extremely difficult to squeeze grease into those spaces. 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 some components – e.g. the bottom bracket, the headset, the wheel hubs.

Lubricating oils are the normal lubrication for roller chains. Lubricants for bike chains are presented in plastic drip bottles. The idea is that an oil will penetrate the space and form a lubricant film. There are aerosol or spray lubricants. Some are general purpose and some are for motorcycle drive chains or other chain drives.

Research & Testing

A researcher needs to justify time and devote resources. A university may fund this, but often a researcher needs a grant or other funding from an external source of funds. In the neo-classical economics that dominates thinking about innovation, markets and consumption, an innovator can disrupt an industry and compete with established manufacturers – if the invention can attract capital investment, which requires financial engineering as well as technical engineering.

Racing was the dominant factor in promoting sales of bikes and parts in the bicycle industry in the more afffluent parts of the world in the 20th century – manufacturers publicized their products based on the achievements of teams of racers or the team leaders/stars in races. Bicycles changed in the 1960s and 1970s. Some riders learned how to repair road bikes, and to modify and build bikes – the origin story of how the first mountain bikes were made, and of many companies selling goods and services to cyclists. Knowledge about repairing and maintaining bicycles trickled out and down. Racers, mainly in European events, experimented with using paraffin wax (a synthetic wax manufactured from petroleum distillates). Paraffin had to be melted to be applied, which required removing the chain – a drawback. (Paraffin wax was among the lubricants used in the tests by Spicer et al. at Johns Hopkins in 2001, above.)

Published academic research on bicycle chains was sparse in the 19th and 20th centuries. Published research on industrial and automotive lubricants was more popular.

A (paywalled) paper by James B. Spicer of Johns Hopkins University and others published in the Journal of Mechanical Design, Volume 123 at pp. 598-605 in 2001, “Effects of Frictional Loss on Bicycle Chain Drive Efficiency” addressed lubrication. Other published research by Professor 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.

Journal of Mechanical Design, Volume 123, p. 598

In a press release by Johns Hopkins University, Professor Spicer is quoted:

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 researcher speculates that a bicycle lubricant does not play a critical role under clean lab conditions, using a brand new chain. But it may contribute to energy efficiency in the rugged outdoors. “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.”

[Emphasis in this post]

John Hopkins University News Release, August 19, 1999

The 3 lubricants used in the test made only small changes in the results; there is no result stated for any test of unlubricated chain. The idea that lubricants are unnecessary is contrary to the experience and beliefs of engineers, tribologists, industry and cyclists. The stated speculation is why lubricants work when real chains get dirty and are sprayed with water. The article and news release did not shed light on what lubricants did and which lubricants were best. The Johns Hopkins tests were full Load Tests (see Part 2) which had a range of error of +/- 1 %. Josh Poertner of Silca (see Part 2) told a story about the development of Silca Synergetic (wet) chain lube in his Marginal Gains podcast in November 2020 “Lubes & Chains & Marginal Gains“. His comment on the roles 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 reseach into a product that people can get their hands on”

Marginal Gain Podcast: Lubes & Chains & Marginal Gains

Industrial discoveries are guarded from imitation and distribution to protect the advantages of “innovators”.

Lubrication engineers, tribologists, and other experts, whether employed by academic institutions or businesses developing and selling products, refer to standards that are generally accepted to describe things that are believed to happen according to physical laws. ASTM International (formerly the American Society for Testing and Materials) is the body that sets standards for lubricants and lubricant testing. There are abrasion testing machines that can be used to test for metal on metal wear by applying known force (a weight on lever) to a sample of metal against a metal wheel turned by the energy of an electric motor at a known speed. These machines are not cheap. It would be remarkable if any cyclist had such a machine or the knowledge and skill to use it. These devices are used in industry to test and demonstrate the effects of lubricants in reducing friction

ASTM does not appear to have, as far as I can tell, standards for bicycle chains and lubricant; it has standards for materials. I have not seen any lubricant vendor refer to these standards. I am not aware of any agency or body that tests lubricants and certifies that lubricants consistently meet standards.

Penetration & distribution

A fluid lubricant forms a film on metal to allow surfaces to move against each other with less friction. A bicycle chain only needs a few drops of an effective lubricant to form a film in the spaces between the moving metal surfaces that bear on each other in bike chains. The film should not be displaced by the operation of the device or the introduction of foreign liquids such as water. Chain lube should be thin enough to penetrate into the spaces where metal surfaces are in contact, and viscous enough to adhere to the metal parts and form a film coating the metal parts it is protecting. In the language of tribology, a chain lubricant might form a tribofilm if the lubricant chemically reacts to the metal. Technically, a bike chain lube does not form a tribofilm unless it reacts. John Allen, writing in 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 on Chain Maintenance

John Allen added this note:

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

Brown & Allen, Chain Maintenance

David V. Herlily’s Bicycle – the History (2004) noted that an oil bath was designed by the English innovator John Marston, of Sunbeam Cycles, Wolverhampton, and featured in his Golden Sunbeam model. It was a large and heavy item, with some drawbacks. Oil baths did not become popular on bicycles – or on internal combustion motorcyles either.

Drip lubes – Wet/dry

Motor vehicle engine lubricant 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 the the storage vessels.) Engine oil is made with a base stock that must be capable of flowing and adhering to metal surfaces. It altered by additives to help remove the residue of combustion. The additives can chemically affect the surface of metal. The base stocks that lubricate are in demand. The ideal base stock for bicycle chain lubricants is not known. Engineers believe that a good lube can be designed. Oil industry engineers have developed Polyalphaolefin and other “synthetic” base stocks for motor oil for racing, and other premium motor oils.

Through most of the 20th century motor oil was widely available and inexpensive. It was easily dripped or trickled onto the chain with small oil cans. It could penetrate. It could loosen oxidized metal (rust), and withstood some of the rigors of use as a chain lubricant. It was widely used to lubricate motorcycle and bicycle drive chains, but is no longer the preferred motorcycle and bicycle chain lube. Several factors explain the shift:

  • chemically engineered petroleum is used to manufacture many modern products:
    • combustible fuel (gasoline or petrol, kerosene);
    • mineral spirits: solvents, paint thinners and cleaning products;
    • lubricants (motor oil and mineral oils); and
    • plastics;
  • the price of oil changes and refineries have changed the way oil stocks are allocated;
  • the oil industry changed the way in makes and sells motor oil to suit the recommendations of automobile engine manufacturers;
  • motor oil was a thick or heavy oil and had the drawbacks of “wet” lubes;
  • removing it required the removal of the chain in the years before master links and other chain removal tech, and the use of solvents and
  • environmental factors made it harder to deal with waste material – excess oil and solvent..

Modern solvents, multi-use household mineral oils and are not suitable for use on bicycle chains. Sheldon Brown & John Allen listed lubricants not to use 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, Chain maintenance

Detergent additives in modern (early 21st century) motor oil, noted in that article, may be a factor, but that issue and the decline of the use of motor oil to lubricate bike chains could have been explained better. Mixing additives into refined and manufactured oils is accepted in industry. The idea of mixing detergents and oils can tempt marketers to advertise oils as both lubricating and cleaning. This is a difficult combination for bicycle chain oils.

The oil industry sold/sells petroleum products, including lubricants, to manufacturers who package and sell bicycle chain lubricant fluids. The normal retail packaging for bicycle lubricating oil is a small drip bottle which can dispense a few drops or a thin stream. Aerosol and other sprays are used to dispense industrial, motorcycle and household multi-purpose solvents and lubricants, but such devices are not popular with cyclists. The economic structure of the relevant industries depends on millions of consumers buying millions of small bottles and annointing their chains with drops of lubricant. Bicycle chain fluids are conventionally labelled wet or dry. Both need to be refreshed or periodically reapplied, on reasonably clean chains.

  • Wet lubricants are marketed as useful in protecting the chain from water, but:
    • No oil based lube is 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 are usually oily enough to penetrate into the working spaces, but need time to penetrate;
    • Even thick oils will be propelled out of the pin/bush/roller and link plate spaces; and
    • Wet lubes pick up dust and contamination.
  • Dry lubes are made up of a carrier fluid, a solvent, blended with a lubricant, an oil and additives. In theory, the carrier penetrates the chain’s spaces and dissipates or evaporates, leaving a coat of lubricant. Some dry lubes are marketed as made of enhanced lubricants or as containing cleaning agents and lubrication enhancing substances:
    • paraffins (waxes);
    • PTFE (Teflon),
    • carbon tubes,
    • zinc dialkyl dithiphosphates (ZDDP), molybdenum disulfide, tungsten disulfide and other metallic additives; and
    • nanoparticles or other substances.

The use of carrier fluid is known to thousands of persons who are mainly employed in a few universities or some of the cycling industries. Manufacturers of lubricants are not open about how lubes are made. Manufacturers can and do claim all sorts of things about chain oil, and do not describe ingredients with any precision. Many cyclists know that the lubricating oil in a dry lube traps dirt and degrades quickly when water gets onto and into a chain.

Factory Grease

Bicycle chains are covered in something called “factory grease” when shipped from the factory covering all metal surfaces, including the outside of the link plates. The factory grease holds dirt because any dust in the air adheres to this grease. Factory grease on the outside of the plates should be wiped off. The question of removing more factory grease is controversial. I have not seen a list of what chain manufacturers say they are using. Many believe it is cosmoline, an anti-corrosive coating; some manufacturers may be using cosmoline. Cosmoline is not marketed as a lubricating grease. Some use grease, of some kind.

The practice of bike manufacturers and bike shops is to install the 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 may apply some bike chain lube to make the chain sound more quiet and perform when a test rider shifts gears. Most 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 modern master links, is a task. The use of solvents raise a series of problems.

There is a body of opinion that removing factory grease is necessary before applying other lubricants.

E-Bikes

There are e-bike lubricants on the market, and other specialty lubricants are expected.

Pending – in progress – outline

  • Testing
    • Efficiency
    • Zero Friction cycling;
    • Silca;
  • Modern lubricants;
    • Additives
    • Test wars
  • Cleaning
  • The modern choices

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