Luctor et Emergo

Bike Chains, Part 3

—

by

Tony Dalmyn
in

Table of Contents

Preliminary

Endless Post

This is Part 3 of a series of 9 posts organized as a single work,
collectively “endless”. There are 8 parts, individually published as
posts on this blog, and a table of contents of the series in the 9th post. The series is organized into sections, numbered for reference, in the series table of contents and in the table of contents for each post. From March-September 2024 I reorganized and revised the long article extensively.

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 19th and 20th centuries. The industrial view, historically, was that generous lubrication with fluid lubricants was better.

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 Drive Trains

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.

Electronic magnifying glasses and microscopes can be used to make still picture 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

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 2this article refers to the goals of mechanical engineers and bike mechanics, and the science and engineering of making lubricants 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

However, that article like many written for cyclists, does not explain how lubricants have been 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 3a 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

It is not clear why he expects academic researchers should serve industry this way, but it appears to be part of vision about science and business.

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 work when 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 firm manufacturing drive train components developed product lines for road bikes, mountain bikes and more recently 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. The basis for cleaning before lubrication is stated in the rule “Never oil a chain on the bike” in this article published in the BiTI (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

BikeGremlin pointed out that several lubricants may achieve the goals of chain lubrication in its post or article Comparative overview of bicycle chain lubricants. However, solvents and multi-use household mineral oils are not suitable for use as bicycle chain lubricants. 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 tests4See 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 5ZFC 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.

Comments

2 responses to “Bike Chains, Part 3”

  1. Bike Chains 1 – Chain Wear & Research – Luctor et Emergo

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

    Reply
  2. Bike Chains Project – Luctor et Emergo

    […] Lubrication Science – What is the science?; […]

    Reply

Leave a Reply

Your email address will not be published. Required fields are marked *