A track bike, also known as a track bicycle, is a type of bicycle designed for racing on a velodrome or outdoor track. Unlike road bicycles, track bikes are fixed-gear bicycles, meaning they have only a single gear ratio and no freewheel or brakes. There are three different types of track bikes, each suited to different events: endurance events, sprint events, and time trial/pursuit events.
The frame of a track bike 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. The dropouts or track ends face rearwards to facilitate chain tension adjustment, and a true track fork has round-section blades for greater lateral stiffness when sprinting.
The geometry of a track bicycle frameset differs from one used on the road by having a higher bottom bracket, shorter chainstays, steeper seat tube angle for a more aerodynamic position, longer reach, and very tight clearances between wheels and frame tubes. Modern track frames use 120 mm spacing for the rear hub, and some small-size track frames often have substantial toe overlap with the front wheel that is not an issue for velodrome riding but can make slow-speed turns difficult.
Track bikes are meant for track racing and are not meant for road riding. They are stiffer in nature to maximize acceleration and power transfer, particularly for sprinting, and are more aerodynamic, with wind resistance at such high speeds on the track a crucial factor in design. Carbon wheels with tubular tires are also preferred for this reason on premium models, with deeper rims also suitable.
