Bike Chains 1 – Chain Wear & Research

Table of Contents

Finding Chain Wear

In April 2021, I thought had less than 2,000 Km on the KMC X11 (11 speed) chain on my Cannondale Topstone gravel bike since purchasing the bike in August 2019. Actually, when I did the math, it was over 4,000. I was not clear on the industry standard for 11 speed chain elongation and chain replacement. I am not an engineer or mechanic. I have done basic home maintenance on my bikes.

I had been washing the chain it in a Park Tools CM-5.3 Cyclone chain cleaner and applying new lube every two or three weeks. I had used ProGold Pro-Link and Muc-Off’s retail dry lube product, as opposed to other more expensive Muc-Off “race” products. I had problems when chain did not respond to the shifters, or skipped, or seems to make rubbing noises. The Park Tool CC-3.2 chain checker was reading that the chain was worn and should be replaced. I located a SRAM PC 1170 chain and a supply of SRAM Powerlinks (SRAM proprietary master links). This was fortunate, in view of the effects of the Covid-19 pandemic on the manufacturing and shipping of bicycle components. I was my introduction to replacing the chain on a modern bike.

Searching the Web

Limitations

Searching the web in a search engine for about bicycle chain cleaning, maintenance and lubrication is a flawed way of learning. Search engines look for web content. The web came into being a century after mass production of safety bicycles and components began. Information about materials, designs, mass production and marketing was not necessarily written down, or digitized, or put on the Web. Written material may have been copyrighted or paywalled. If it is on the Web, it may not have attracted searches or hits. Search engine algorithms follow and lead the crowd

Web searches generate long lists of links. Some search engine hits are predominatly text or text with static images. Search engines may show hits for videos , including YouTube videos but usually not podcasts. For podcasts a user need to seach for podcast in an podcast index. Many or most text pages and videos:

  • are direct advertisements for products, or endorsements;
  • are low value “reviews”.

Searches for recorded audio and video material (podcasts, YouTube) appear to depend on a few searchable lines of text, an item title, or the organization of the resource (the identity of an author or publisher, channels, tags, indices etc.). After gettting a good hit, a user needs luck and time to find the moments when a subject will be explained.

Reviews can be useful in finding products, but have limited value in evaluating products. It is not possible to find out how the author or publisher has influenced, or has preconceptions. Many reviews reflect personal experience in conditions that are not clearly explained, or quick reactions. The comparisons are between the products which the author or publisher mentions i.e. are limited to as to what is available or known to the writer. The testing, if any, is not scientific and does not assess the actual conditions of use. Many reviews or overviews are catalogues of methods, sometimes narrow, sometimesoverly broad. Many make improbable claims about products.

Comments in forums may reflect experience, but the amount of experience with the products is not clear. Some comments reflect frustration that the bike industry keeps selling more expensive new bikes and components while bikes are harder to maintain without tools, supplies and knowledge.

There are many resources reflecting many opinions. There is no “wise crowd”; people who sell, fix, buy or ride bicycle do not assess facts the same way.

General Knowledge Resources

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

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

Wikipedia (October 2021) on Bicycle Chain

Scientists and Engineers

Some scientific research and publications are summarized in Bike Chains 3 in this series, under the headings and subheadings Lubricants: Scientists, Lubricants: Paraffin, and Lubricating a Chain: Academic Research.

Bike Mechanics

The late Sheldon Brown, a bike mechanic in Boston, and a modern polymath, started writing on the Web by the early 1990s. He had contacts among local riders and shops, and participated in Usenet news groups and other online forums on cycling. His web wages on cycling were hosted by his employer, Harris Cyclery. He wrote extensively and collected internet material. The Bicyle Technical Information pages were a leading online source of information about bicycle repair and bicycles. The pages captured parts of the histories of bicyles and components, manufacturing, repair, touring and riding. The publishing industry lost interest in publishing printed books about those subjects. Sheldon Brown promoted Sutherlands Handbook for Bicycle Mechanics by Howard Sutherland, (the 6th and 7th editions are available as of 2022 from Sutherland’s Bicyle Shop Aids in California), and published articles by several authors on technical bicycle repair and maintenance matters.

The BTI pages reflect a perspective on innovations in the industries in the 1990s, and have not addressed all the maintenance issues arising from early 21st century innovations. A few comments that do not hold up (for instance, that riders should not try to remove factory grease from a chain). The BTI pages that mention chains, lubrication and maintence include:

The contributors to the BTI pages, other than Sheldon Brown, had varying experiences in life. Some were engineers and mechanics, or knew about some industries. Some were computer enthusiasts. Some read science fiction. Expressions like there ain’t no such thing as a free lunch (“TANSTAFL”) (also see the Quote Investigator site’s page 2016/08/27) or kludge were used to describe the realities of riding and fixing bicycles and the results of financial, organizational and decision making processes of bicycle manufacturers, politicians and traffic engineers. TANSTAFL was adopted by the economist Milton Friedman, and has become a libertarian slogan implying “you get what you pay for“. I use TANSTAFL to mean “it is what it is“.

Sheldon Brown’s Bicycle Technical Information (“BTI”) pages have been updated since his death in 2008, and continued to be published after Harris Cyclery closed in June 2021.

This comment on how riders adhere to beliefs about chain maintenance rings true:

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


Sheldon Brown & John Allen, Bicycle Technical Information, Chain Maintenance

The resources at BikeGremlin have been written with care, and takes the range of views and experiences of some riders and mechanics into account. It addresssed lubrication in the article Bicycle Chain Lubricants explained, apparantly written in 2016 and updated in 2018 and 2021.

BikeRadar is careful and thorough. It ran its Complete Guide to Bike Gears in April 2020, an introduction and overview of drive trains.

Online Magazines, Journals & Cycling Sites

CyclingTips is an online cycling magazine with strong technical coverage. It published a few “endless FAQ” articles on some components and issues of maintaining modern bicyles. These are detailed articles, periodically revised. For instance:

Component or issueStartedRevised
Disc BrakesMay 2018August 2019
Tubeless Tires2019October 2021
Waxing ChainsAugust 2020March 2021

CyclingTips has covered chain maintenance, cleaning, lubrication and wear and modern pioneers of testing lubricants and chains in text articles and audio media: CyclingTips NerdAlert podcast is devoted technical and repair issues. The panelists often mention the cycling industries’s history of selling products that have drawbacks and flaws.

Jason Smith, an engineer in Boulder, Colorado, USA started and ran a business called Friction Facts in the period from 2012 to 2015. The story of Friction Facts, efficiency tests and the publication of the early efficiency tests results is summarized in Bike Chains 4 in this series, under the heading Efficiency testing.

Adam Kerin, in Adelaide, South Australia, Australia started a business called Zero Friction Cycling (“ZFC”) in 2017. The story of ZFC and durability tests is summarized in Bike Chains 4 in this series, under the headings Efficiency testing and Durability/Wear testing. ZFC has published chain wear and lubrication material on the Web.

Josh Poertner and other broadcasters hired, employed or sponsored by Silca Velo have done podcasts and videos (YouTube channel name Silca Velo or the name/theme “Marginal Gains”:

  • video
  • podcasts
    • interviewing people who test lubes and chains; and
    • about cleaning chains and applying lubricant;
    • Marginal Gains podcast, November 2020 “Lubes & Chains & Marginal Gains”.

Bicycles, Chains, Friction, Lubricants

Safety bicycles

The 21st century bicycle is an industrial product evolved from the safety bicycle which was an industrial product created and manufactured after late 19th century innovations in material and manufacturing. The high mount bicycles (including penny-farthings) in use in the 1860’s and 1870’s had pedals and cranks that directly drove a large drive wheel. A drive chain lets a rider seated between the wheels power a geared drive wheel. The safety bicycle has been incrementally redesigned for more than a century. An article in Bicycle Times in 2017 is illustated with images of 25 influential bicyle designs, mainly in the 20th century. The article does not include samples of the designs that have dominated the bicycle markets since about 1993, except a 2005 fat tire bike. It does not include cargo bikes of any era. It does not include any e-bikes.

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

Chains

After experimentation, by the early 20th century the bike industry began to use bushed steel roller chain on most bicycles. While the bushingless chain the dominant design, the roller chain has been a constant. Bicycle roller chains have been made of steel since they were introduced, as far as I can tell. Steel had the tensile strength for the purpose, and could be produced with relatively smooth surfaces. The parts that connect the links are made with tight tolerances, for transmission of force. There are microscopic gaps between pins and rollers and/or bushings, which allow the links to pivot to rotate on the chain rings and the cogs of the driving wheel transmission apparatus. The basics of roller chain are alternating inner and outer links, the ability to bend at the ends of links, and rollers.

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

The chain has to run over and under a chain stay – usually on the right side of a conventional two wheeled safety bike. The chain stays are welded or attached to the bottom of seat tube near the bottom bracket shell, and to the seat stay. The chain stay is one side of a closed triangle. Before the use of master links, it was necessary to use a tool to displace a pin to “break” and remove the chain. Removing the chain was not a common practice before the development of master links. Master links, devices that replace a single outer link, were noted in the BTI glossary. Master links became common in the 1980s and 1990s. They make it easier to remove a chain for cleaning, maintenance and replacement. There is more on master links in Bike Chains 2 in this series under the heading Master links.

Even with master links, removing a chain is an operation which many cyclists do not have the time, tools or knowledge to attempt.

Some parts of the history of the bicycle roller chain supply chain have been discussed by historians of sport or commerce. The Japanese firm Shimano is one of the dominant forces in manufacturing bicycle components, including cranks, derailleurs, and chains. It outsources a portion of production of its branded chain to manufacterers else in Asia, e.g. KMC of Taiwan. As of the early years of the 2020s, most chains are manufactured in Asia.

Friction, Wear & Lubricants

Lubricants are materials that are applied to surfaces of other materials to reduce friction when force applied to the materials and the surfaces move against each other. A lubricant reduces kinetic friction by changing static friction to lubricated friction, allowing metal surfaces to slide or turn without getting hot and making noise.

A metal roller chain does not stretch. It wears, which makes it get longer – a longer chain fails to fit the cogs and fails. Microscopic wear on individual links adds up.

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

Academics and industry researched and developed many lubricants for many purposes. Bike chain lube has become a specialty market. Bike shops sell what they can get from suppliers; bike owners/users have limited help in finding and choosing the best lubricants. The best is not easily found and applied, or necessarily very effective at avoiding chain wear.

Chain Replacement

Specifications & Standards

By 2021, most modern bikes, other than e-bikes, on the market (in Canada and the USA) had rear wheel cog cassettes with 11 or 12 cogs. Elongation of 11 and 12 speed bushingless chains by .5 – one half of one percent – of the length of a chain is the replacement point. I did not find material that explained how this standard was set. It is implicit in the design of chain gauges (chain checker tools), and known to the employees of bike shops and to some some users. 11 speed chains and rear cassettes were introduced by Campagnolo in 2008, and by Shimano in 2013. 11 speed cassettes and chains became a common feature of new bikes. The design, release and sale of modern chain gauges followed.

The .5% standard translates to about 7 mm over the length of a chain. The length of a modern chain varies, depending on the length of the chainstays, the sizes of the largest chain ring and the largest rear cog, and the rear derailleur shape and size. A chain may have 55 to 59 links (counting a link as 1 Outer plus 1 Inner) or links 110 to 118. A chain may and be 1397 mm. to 1473 mm. long A chain gauge checks for wear in a span of 12-14 links. The gauge has to precisely cut/machined and precisely used to detect elongation of .5 mm.

Many riders assumed that steel chains were invulnerable – at least very durable. The existence and marketing of chain gauges suggest the cycling component, tool, and maintenance industries expect riders to check and replace chains.

Measurement of Wear

There is more on chain gauges and measurement in Bike Chains 2 in this series under the heading Checking for Chain Wear.

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