Track bicycle /

A track bicycle or track bike is a bicycle optimized for racing at a velodrome or outdoor track. Unlike road bicycles, the track bike is a fixed-gear bicycle and so has a single gear and neither freewheel nor brakes. Tires are narrow and inflated to high pressure to reduce rolling resistance. Tubular tires are often used but are becoming more obsolete due to advances in clincher tires negating the benefits of tubulars. A track frame is specific to its use. Rigidity is more important than lightness. Frames for sprinting are as rigid as possible, while those for general racing as aerodynamic as possible. The governing body, the International Cycling Union (UCI), sets limits on design and dimensions as well as the shape and diameter of the tubes used to construct the frame. A track bicycle differs from one used on the road by having: Typical track frames use 120mm spacing for the rear hub. The dropouts or track ends face rearwards to facilitate chain tension adjustment with very tight clearances in front of the rear tire that would prevent wheel removal with forward-facing dropouts. Frames can be made of steel, aluminium, carbon fiber, or titanium. Carbon fiber is most common at the