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Atrack bicycle ortrack bike is abicycle optimized for racing at avelodrome or outdoor track. Unlikeroad bicycles, the track bike is afixed-gear bicycle; thus, it has only a single gear ratio and has neither afreewheel nor brakes.Tires are narrow and inflated to high pressure to reducerolling resistance.

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The first bicycle race is popularly held to have been a 1,200 meter race on the 31 May 1868 at the Parc deSaint-Cloud,Paris. It was won by expatriate EnglishmanJames Moore who rode a wooden bicycle with irontires.^[1] The machine is now on display at the museum inEly,Cambridgeshire, England.

TheUnion Cycliste Internationale was founded on 14 April 1900 by Belgium, the United States, France, Italy, and Switzerland to replace theInternational Cycling Association, which had been formed in 1892, over a row with Great Britain as well as because of other issues.

A trackframe is specific to its intended use, with emphasis on rigidity and lightness. Frames for sprinting seek to maximize rigidity, while those for general racing seek to reduce aerodynamic drag. Thedropouts ortrack ends face rearwards to facilitate chain tension adjustment. A true track fork, unless aerodynamics are the primary consideration, has round-section blades for greater lateral stiffness when sprinting. The crown is sometimes drilled to give the option of mounting a front brake when the bike is used on the road.

The governing body, theUnion Cycliste Internationale (UCI), sets limits on design and dimensions as well as the shape and diameter of the tubes used to construct the frame. The UCI permits special exceptions for the construction and geometry of track bikes.^[2]

AKeirin bike is a track bike for Keirin races in Japan that meets the strict system of standards of theJKA Foundation (Japan Keirin Autorace Foundation), the governing body for Keirin competitions, still popular under the abbreviation of its predecessor body - NJS (Nihon Jitensha Shinkōkai or the Japanese Bicycle Association).

A track bicycle frameset typically differs from one used on the road in the following ways:

• higherbottom bracket – so the pedals are less likely to strike a steeply banked track
• shorter chainstays and overall wheelbase – befitting the tight quarters of velodrome races
• steeperseat tube angle and longer reach – trading long-term comfort for aerodynamic benefits
• steeper head tube angles and lower fork offset to achieve highertrail and lowerflop – for stability at speed in close proximity to other riders

These changes represent substantial compromises compared to a typical road bike. For example, even medium-sized track frames often have substantial toe overlap with the front wheel; while not an issue for velodrome riding, it can make slow-speed turns difficult if the bike were used on the road.^[3][4][5]

Frames are assembled from tubular elements (typically with round or elliptical cross sections), or cast in a mould for "one-piece" type models. The most popular materials for frame building includesteel,aluminium, ortitanium alloys,carbon fiber, or a combination of these materials. Carbon fiber frames are most common at the professional level.^[6]

Track bicycles have only one drivesprocket (or cog) and one chainring, so the size ratio is relevant. A lower gear ratio allows quicker acceleration or 'jump' but can limit top speed. A larger gear ratio makes sustained speed easier, important inpursuit racing,time trial and bunched races such as points or scratch events.Without a good jump, the rider risks opponents accelerating away; without good sustained speed, the rider will be unable to keep up with a fast race. Track sprinters make a compromise by using particular gear ratios that allow them to reach race speeds at a relatively high cadence (pedalling), around 130-135 revolutions per minute (r/min).^[7]

Long-distance attempts such as thehour record sometimes use high gear combinations such as 52×12 or 55×14.Ondřej Sosenka used 54×13 with 190 mm cranks to set the 2005 record.

Bicycle chains used in track, fixed gear and single speed cycling come in two common roller widths (the internal width between the inner plates), which is either 2.38 mm (3⁄32 in) or3.18 mm (1⁄8 in). The chainring, sprocket and chain should all be the same width. Although a wider chain will work on a narrower chainring or sprocket, it is not ideal. A narrower chain will not work on a wider chainring or sprocket. Newer bicycles withderailleur gears use bushingless2.38 mm (3⁄32 in) chains which flex, making gear changing possible. There are also3.2 mm (1⁄8 in) bushingless chains on the market, which can be lighter or cheaper. Track bicycles, however, need increased strength rather than a lightness or a flexibility, so most of the track chains still use the full-bushing design.

Tubular tires are most often used in track racing and training, though advances inclincher tire design have seen them being used somewhat more often.^[6]

• Outline of cycling
• Path racer
• Keirin

• Cycle types
• Track cycling

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