Bike Chains 3 – Lubrication Science

Table of Contents

Lubricants

Science

The bicycle is made of materials and components “invented” by mechanics and engineers before late 19th century scientists articulated the periodic table of elements or the fundamental modern theories of physics and chemistry. The physicist Carlo Rovelli wrote:

The ability to understand something before its observed is at the heart of scientific thinking.

Carlo Rovelli, The Order of Time (2018)

Inventors, engineers, manufacturers, mechanics engineers, and bike people rely on other evidence 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. Bike people can see what happens when a chain is soaked in solvent Engineers can test the 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 moving parts of bicycle chain are not sealed. It was observed, early in this history of bicycle drive chains that lubricating fluids did not flow off the chain and were not flung off by the forces of motion. Enough fluid adhered to the chain, and lubricated, for long enough, to allow the chain to move under “load” and serve a purpose. Chains are manufactured on the assumption that the user or purchaser will lubricate the chains. The petrochemical and lubrication industries manufacture and sell fluids to lubricate bicycle chains.

Refined Petroleum Lubricants

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.

Engineers, scientists and inventor petroleum worked out the principles of organic chemistry and chemical engineering in the 19th century, before the modern theories of atomic bonding were established. They w 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 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. The fluid lubricants used in industry and with motor vehicles have been manufactured products made with refined petroleum oils since the late 19th century. The history the many geological oils is addressed in works on geology, industry and ecology. Some works have focussed 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.

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, regardless of knowledge or skill, calling themself a tribologist.

Bicycle Drive Trains

Silca Velo 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 lubricants should be placed. Silca explains the basic working theory that a lubricant forms a film that lubricates the metal surfaces, preventing the metal surfaces wearing each other down.

The long technical article Bicyle Chain Lubricants Expained at the web site BikeGremlin describes the 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

BikeGremlin explans fluid lubricants – lubricating oils – thororoughly. It explains 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 present.

The dominant ideas are that a lubricant:

  • should adhere to the metal chain, and
  • form a barrier (a fluid forms a film) to allow the metal surfaces to move against each other with less friction, but
  • should not allow dirt and contaminants to adhere to the chain

Fluid, Grease, Wax, Solid

Fluid lubricants can be applied to the joints between links of bike chains, and will penetrate the spaces between the moving metal surfaces. The lubricant is believed to form a barrier or film. The lubricant adheres to each surface and slips or sheers. The metal is less abraded (worn away). 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.

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 crankcase of 4 cycle internal combustion engines) is an adequate chain lubricant, except that it has some 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 noted that light machine oil, for instance sewing machine oil, had the right viscosity.

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 that the lubrication industry uses in bike lubes.

There are fluid lubricants that disperse and suspend in air – 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 or other chain drives.

In industry, oilers, specialized employees, lubricated open bearings in various devices with lubricating “oils” in the 19th and 20th centuries. The industrial view, historically, was that generous lubrication with fluid lubricants was better. The industrial vision or model of how lubricants worked include reducing friction and breaking down and washing 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).

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 or wax to a roller chain in a way that properly gets lubricant into the spaces between metal surfaces inside the joints.

Motor Oil, Gear Oil and Machine Oil

Through most of the 20th century automotive engine oil (motor oil) was widely available and inexpensive. Low viscosity oil was easily dripped or trickled onto a bicycle drive chain 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 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.) Engine oil is made with a base stock that must be capable of flowing and adhering to metal surfaces. Oil industry engineers have developed Polyalphaolefin and other “synthetic” base stocks for motor oil for racing, and other premium motor oils.

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

The oil industry changed the way it makes and sells motor oil to suit the recommendations of automobile engine manufacturers. Motor oil is more viscous that other lubricating oils to operate in the hot conditions of internal combution engines. 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. The production of automotive lubrication oils became specialized.

Motor oil was widely used to lubricate motorcycle and bicycle drive chains, but is no longer the preferred 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;
  • refineries have changed the way oil stocks are allocated;
  • motor oil was or became 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.

Drip Bottles, Marketing, Wet and Dry

Marketers for lubricant manufacturers often use the language of lubrication engineering and manufacturing.

The idea of using special bike chain lubes and dripper bottles became dominant in the 1980s. The oil industry sold/sells petroleum products, including lubricants, to manufacturers who package and sell bicycle chain lubricant fluids. Drip lubes are liquids or fluids. The normal retail packaging for bicycle lubricating fluid 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. Manufacturers of lubricants are not open about how lubes are made. Manufacturers do not describe ingredients with precision.

The idea of mixing detergents and oils can tempt 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.

Bicycle chain fluids are conventionally labelled wet or dry. Some manufacturers market “wet” and “dry” versions of some branded products. Both wet and dry lubes need to be periodically reapplied, on reasonably clean chains. Both are manufactured with chemicals distilled by the petroleum industries. Dry lubes are lower viscosity, or runny. Drip lubes may be made up of a carrier fluid, a lubricating oil, and additives. The carrier fluid reduces viscosity to enhance the the lube’s ability to flow into the chain’s spaces. As a rule a dry lube has significant amount of carrier fluid and has lower viscosity. Wet lubes are as viscous as motor oil or gear oil.

The author of the article Bicycle Chain Lubricants Explained at BikeGremlin has an opinion on dry-drip lubes and solid lubes:

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

Fluid “dry” drip lubes might be called dry-drip. They can be wiped off the outside of a chain, and do not trap as much visible dirt on the outside of a chain. Dry-drip lube degrades quickly when water gets onto and into a chain.

Using carrier fluid is a method of manufacturing used to manufacture automotive, industrial and household lubricants. Carrier fluid is not a lubricant for a chain drive. 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. Carrier fluid is a term used by engineers and other specialists who deal with the distillation of petroleum, and manufacturing and using lubricants. 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. The related term base oils refers to refined petroleum or synthetic lubricating oils.

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. “Carrier fluid” is not a Wikipedia entry, as of January 2022, but is used in several entries.

Wet lubes have higher viscosity, and greater adhesive properties. Wet lubes, in theory, are thin enough to run and thick (viscous and adhesive) enough to stick. Generally, wet lubes:

  • have more base oil than a dry lube;
  • may be made of a lubricating oil or carrier fluid;
  • may have additives.

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

  • Wet lubes need time to penetrate;
  • Even higher viscosity oils will be propelled out of the pin/bush/roller “sleeve” and link plate spaces;
  • Wet lubes pick up dust and contamination.
  • 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).

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.

Academic Research

A researcher needs to justify time and devote resources. A university may fund this, but often an academic researcher needs funding. 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.

Racing was a dominant factor in promoting sales of bikes and parts in the bicycle industry in the more affluent 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.

A (paywalled/gated) 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. Subsquent 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 (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 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.”

John Hopkins University News Release, August 19, 1999

The dripped and sprayed fluid lubricants made only small changes in the results. The lubricants were fluids with additives, applied as dripped liquid or aerosol. The brand names are not mentioned in the news release. By the end of the 20th century, most bike lubes were fluids in bottles

The stated speculation is why lubricants work when real chains get dirty and are sprayed with water. The article and news release did not say which lubricants were best. The Johns Hopkins tests were full Load Tests (see Bike Chains 4) which had a range of error of +/- 1 %.

Josh Poertner of Silca Velo (see Bike Chains 4 ) discussed the development of Silca Synergetic, an oil based fluid chain lube in his Marginal Gains podcast in November 2020. 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

There is research in industrial and automotive lubricants. 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 that are generally accepted to describe things that are believed to happen according to physical laws. 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. It is rare for a bike chain lubricant manufacturer to refer to ASTM G77 or any other ASTM standards.

Paraffin Wax

Some of the science and history of paraffin immersion is discussed in Bike Chains 7 in this series. The method is explained and discussed in Bike Chains 7.

Lubricating a Chain

Penetration and distibution

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, 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. An oil bath ran the chain into clean oil on every rotation. This diluted contaminants. The chain was sheltered against dirt and moisture. It was a large and heavy item, with some drawbacks. Oil baths did not become popular on bicycles but were features of some motorcycles.

An open or uncovered chain needs to be cleaned and lubricated. Generally cleaning should precede lubrication. The basis for cleaning before lubrication is stated in the rule “Never oil a chain on the bike” in this article published in the Bicyle Technical Information (Sheldon Brown) 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, 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

Unsuitable Lubricants

BikeGremlin pointed out that several lubricants may achieve the goals of chain lubrication in its post or article Comparative overview of bicycle chain lubricants.

Modern solvents and multi-use household mineral oils are not suitable for use as bicycle chain lubricants. 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, Bicycle Technical Information (Sheldon Brown pages) Chain maintenance

Detergent additives in modern (late 20th & early 21st century) motor oil are a factor. Mixing additives into refined and synthetic oils is accepted in industry but “detergent” addititives detract from the usefulness of motor oil. There are other reasons to not use motor oil on a bicycle chain.

Factory Grease

All bicycle chains are covered in “factory grease” when shipped from the factory. Many believe it is cosmoline, an anti-corrosive coating. Cosmoline is not marketed as a lubricating grease. Some manufacturers may be using cosmoline or a similiar coating. Some chain manufacturers – e.g. Shimano claim their factory grease is a lubricant. I have not seen a list of what chain manufacturers say they are using.

Factory grease coats all metal surfaces. 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. Removing the chain and deep cleaning with solvents to remove factory grease is necessary to lubricate a chain by immersion in melted paraffin. It is considered by many to be helpful in using most or all fluid lubricants. The argument is that factory grease adheres to metal surfaces and interferes with the application of lubricants to surfaces that should be lubricated.

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 modern master links, is a task. The use of solvents raise a series of other logistic and application problems.

Dry-drip lube

Some retail chemicals – e.g. WD-40 – use 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. WC-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.

The main weaknesses of dry-drip lubes are that:

  • the carrier 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 that 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 fluid drip lubricants, particularly dry-drip lubes, are not effective to resist chain wear.

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 interpeted as demonstrating that dry-drip lubes could reduce friction , or that dry lubes reduced friction for a short period after being dripped into a chain.

The 2013 & 2014 VeloNews articles (links in post Bike Chains 4) interpeted the FF 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 inthe 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 author of Bicycle Chain Lubricants Explained at the web site BikeGremlin discusses the use of additives in dry-drip 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 other 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:

  • Finish Line Dry Teflon. Finish Line still advertises Dry Teflon bike lube . 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 tests of PTFE enhanced products were favourable to some products, but the interpretation was not clear.

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 fakery without testing and data.


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One response to “Bike Chains 3 – Lubrication Science”

  1. […] scientific research and publications are summarized in Bike Chains 3 in this series, under the headings and subheadings Lubricants: Scientists, Lubricants: Paraffin, […]

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