A bicycle chain is a roller chain that transmits power from the pedals to the drive wheels of the bicycle to propel the bicycle. Most bicycle chains are made from plain carbon or alloy steel, but some are nickel plated to prevent rust or just for aesthetics.

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Obsolete chain designs previously used on bicycles included block chains, skip-link chains, and Simpson lever chains. The first chain had a simple design with no bushings. These had inherent reliability issues and had a little more friction (and loss of mechanical efficiency) compared to modern chains. With these limitations in mind, the Nevoit brothers of the German Diamant Bicycle Company designed a roller chain that used bushings in 1898. More recently, "bushless roller chain" designs have replaced bushed chains. In this design, the bushing bearing surface is integrated into the inner side plates, each plate forming one half of the bushing. This reduces the number of parts required to assemble the chain, reducing costs. The chain is also more flexible laterally as the chainline is not always straight in all gear selections, which is required in modern derailleur gearing. The first solid bush roller patent was filed in 1880 by Renold Chain Company. Early examples of chain-driven bicycles include the 1869 Guillemot and Meyer, the 1879 Lawson, the 1884 McCammon, the 1884 Starley Rover, and the 1895 Diamant. Before the advent of safety bicycles, bicycles did not have chains and pedals were usually attached directly to the bicycle. Therefore, the front wheels are designed to be as large as possible, as the diameter of the wheels limits the maximum speed. Various linkages were invented to increase the effective gear ratio, but without much success. With a chain drive, the maximum speed is determined by the mechanical advantage between the driving and driven sprockets, allowing manufacturers to reduce drive wheel size for safety. It also allows the development of variable gearing, allowing cyclists to adjust gears on the fly according to the terrain, road slope and intensity, and obtain an efficient and workable cadence at different speeds.


Bicycle chains are extremely energy efficient, with one study reporting efficiencies as high as 98.6%. This study was conducted in a clean laboratory environment and found that efficiency was not significantly affected by lubrication conditions. Larger sprockets move the pressure point farther from the axle, putting less stress on the bearings and reducing friction on the inner ring, resulting in more efficient drive. I found that the higher the chain tension, the better the efficiency. "This is not really the expected direction, just based on friction."


How best to lubricate a bicycle chain is a subject of much debate among cyclists. The liquid lubricant penetrates the inside of the links, does not move easily, but quickly picks up dirt. "Dry" lubricants, which often contain waxes or Teflon, are transported by evaporating solvents and remain clean during use. A good rule of thumb for long chain life is to never lubricate a dirty chain. Lubricating will cause the abrasive particles to flow into the rollers. Chain must be cleaned before lubrication. After enough time has passed for the lubricant to penetrate the links, the chain should be wiped dry. Another approach is to change the (relatively cheap) chain frequently. Then proper care becomes less important. Some utility bikes have fully enclosed chain guards that virtually eliminate chain wear and maintenance. On recumbent bicycles, the chain is often run through a tube to keep dirt off the chain and keep the cyclist's legs free of grease and dirt.

= Removal =

On most upright bikes, the chain loops through the right rear triangle made by the right chainstay and seat tube. So unless you can split the triangle (usually the seatstays), you'll have to separate (or "cut") the chain. The chain can be cut with a chain tool or master link. Master links, also called connecting links, allow the chain to be inserted or removed with simple or no tools for cleaning or replacement. Some newer chain designs, such as Shimano and Campagnolo 10-speed chains, have a special replacement pin for use when installing or re-installing a split chain. An alternative to this process is to install a master link such as SRAM Power Link or Wippermann Connex.


Chain wear is often mistaken for chain stretch, which is a problem for long periods of cycling. Wear is the removal of material from the bushings and pins (or half-bushings, also called "bushingless" in the Cedis design, where the bushing is part of the inner plate), not the stretching of the side plates. The tension created by pedaling is insufficient to cause the latter. Because the spacing between the links of a worn chain is longer than the 1/2 inch (12.7 mm) specification, these links do not fit exactly into the space between the sprocket teeth, resulting in increased sprocket wear and chain skipping. may occur. In a derailleur drivetrain, pedaling tension causes the chain to slip over the sprocket teeth and fly into the next alignment, reducing power transfer and making pedaling uncomfortable. Since chain wear is greatly aggravated by dirt entering the links, chain life depends primarily on how well the chain is cleaned and lubricated, and not on mechanical loads. Depending on usage and cleaning, a chain can last up to 1,000 km (600 miles) (such as cross-country or all-weather use), up to 3,000-5,000 km (2,000 miles) for a well-maintained derailleur chain. ~ 3,000 miles). High quality chains in perfect condition, single gear or hub gear chains with full cover chain guards last over 6,000 kilometers (4,000 miles). Nickel-plated chains also give some degree of self-lubricating properties to the moving parts as nickel. is a relatively non-corrosive metal. Chain wear rates are highly variable. One way to measure wear is with a ruler or machinist's ruler. The other is with a chain wear tool, which usually has "teeth" about the same size as the sprocket. It is attached to the chain under a light load and if the teeth fall all the way in, the chain should be replaced. The 20 half links on the new chain are 10" (254 mm) and it is recommended to replace the old chain before it reaches size 10+1⁄16" (256 mm) (0.7% wear) . A more conservative limit is for an old chain with 24 half-links measuring 12+1⁄16 inches (306 mm) (0.5% wear). If the chain wears beyond this limit, it can also wear the rear sprocket and, in extreme cases, the front chainring. In this case, the sprocket teeth are unevenly worn (hooked in severe cases), so the above "flying" may continue even after the chain is replaced. Replacing a worn sprocket cassette and chainring after losing the chain replacement window is much more expensive than simply replacing a worn chain.


Chains used on modern bicycles have a 1/2 inch (12.7 mm) pitch, which is the distance from pin center to pin center. In ANSI standard #40, the 4 in "#40" indicates the pitch of the chain. 1/8th of an inch. ISO Standard 606 (Metric) #8, where 8 indicates a pitch of 1/16th of an inch. The roller diameter is 5⁄16 inch (7.9 mm). 1976: Shimano briefly produced a proprietary 10-pitch Dura-Ace track-only system with an (approximate) pitch of 10 mm (3⁄8 inch) from 1976 to about 1980. This is called the Shimano Dura-Ace 10 pitch. Shimano 10 pitch system is not compatible with ANSI standard #40 (1/2 inch). The manufacture of parts such as chains and sprockets was prohibited by the Japan Keirin Association, which contributed to its demise.

= Width =

Chains are available in 3⁄32" (2.4 mm), 1⁄8" (3.2 mm), 5⁄32" (4.0 mm), or 3⁄16" (4.8 mm) roller widths (inner width between inner plates). ) there is. 1⁄8 inch (3.2 mm) chains are typically used on bikes with a single rear sprocket, i.e. bikes with coaster brakes, hub gears and fixed gears like track bikes and his BMX bikes. Chains with 3⁄32" (2.4 mm) wide rollers are commonly used on bikes with derailleurs such as racing, touring and mountain bikes. Fixed sprockets and freewheels are also available in 3⁄32" (2.4 mm) width, so fixed gear and single speed bikes can be set up to use thinner and lighter 3⁄32" (2.4 mm) chains. increase. Finally, chains with 5⁄32 inch (4.0 mm) wide rollers are used on cargo bikes and tricycles. On derailleur-equipped bikes, the outside width of the chain (measured at the connecting rivets) is also important. The chain should not be too wide for the cogset and then rub against the larger sprockets. It's also too narrow and can fall between the two sprockets. sprocket. Chains can also be identified by the number of rear sprockets they can support (from 3 to 13). You can also use the list below to measure chains of unknown origin to determine their suitability. 6-speed – 7.3 mm (9⁄32") (Shimano HG), 7.1 mm (9⁄32") (SRAM, Shimano IG) 7-speed – 7.3 mm (9⁄32") (Shimano HG), 7.1 mm (9⁄32") (SRAM, Shimano IG) 8-speed – 7.3 mm (9⁄32") (Shimano HG), 7.1 mm (9⁄32") (SRAM, Shimano IG) 9-speed – 6.5 to 7.0 mm (1⁄4 to 9⁄32 in) (all brands) 10 speed – 6.0 to 7.0 mm (1⁄4 to 9⁄32 in) (Shimano, Campagnolo) 10-speed (narrow) – 5.88 mm (7⁄32 in) (Campagnolo, KMC) 10-speed (narrow, directional) – 5.88 mm (7⁄32 in) (Shimano CN-5700, CN-6700, CN-7900) 11 speed – 7⁄32 to 7⁄32 in (5.5 to 5.62 mm) (Campagnolo, KMC, Shimano CN-9000) 12 speed - 5.3 mm (13⁄64 inch) (SRAM) 13 Speed ​​- Width 4.9 mm - Campagnolo Ekar Wikibook "Bike maintenance and repair" has more information on this topic.

= Length =

New chains usually come in stock lengths that are long enough for most upright bicycle applications. The proper number of links must be removed prior to installation for the drivetrain to function properly. You can extrude a pin connection link with a chain tool to shorten it and add more links to lengthen it. For derailleur gears, the chain is usually long enough to allow shifting to the largest front chainring and chainring. The largest rear sprocket should fit snugly and not be so long that the rear derailleur cannot take up all the slack when shifting to the smallest front chainring and smallest rear sprocket. Meeting both these requirements is only possible if the rear derailleur is compatible with the gear range used on the bike. It is widely accepted that the use of large/large and small/small gear combinations (a practice known as cross-chaining) is not recommended in practice due to chain stress and wear. For single speed bikes and hub gearing, the chain length should match the distance between the crank and rear hub and the size of the front chainring and rear sprocket. These bikes typically have features for fine tuning, such as horizontal dropouts, track ends, and eccentrics on the rear hub or bottom bracket. In extreme cases, half-links of the chain may be required.


To reduce weight, the chain is manufactured with hollow pin and link cutouts. Chains are made of stainless steel, which emphasizes corrosion resistance, and titanium, which aims to reduce weight, but they are expensive. A recent trend is chains in different colors, and at least one manufacturer offers a chain model specifically for e-bikes.


Famous bicycle chain manufacturers include: Renold Campagnolo Roflov AG KMC chain Shimano SRAM Whipperman

See also

bicycle gear chainless bicycle

External links

Wikibook Bicycle maintenance and repair – see Chain section Animation of Shimano gear system

Science News


Definition & Meaning



  • a wheeled vehicle that has two wheels and is moved by foot pedals


  • ride a bicycle



  • a series of things depending on each other as if linked together (chemistry generally in an organic molecule a series of (usually metal (business stores or restaurants or banks or hotels or theaters anything that acts as a restraint a unit of length British biochemist (born in Germany 1906-1979 a series of hills or mountains a linked or connected series of objects a necklace made by stringing objects together


  • connect or arrange into a chain by linking fasten or secure with chains


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