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
A track bicycle differs from one used on the road by having:

• higher bottom bracket so the pedals do not touch a steeply banked track^{[citation needed]}
• steeper seat tube for a more powerful aerodynamic position,
• steeper head tube for more responsive steering,
• less fork rake.

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.
Track bicycles have only one gear so its size is important. A lower gear allows quicker acceleration or 'jump.' But a bigger gear makes sustained speed easier, important in pursuit, 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, he will be unable to keep up with a fast race. Track cyclists practice fast pedalling (cadence) as a compromise.
Long-distance attempts such as the hour record use high gear combinations such as 52x12 or 55x14. Ondřej Sosenka used 54x13 with 190mm cranks to set the 2005 record.




There are two common widths of single speed and fixed gear bicycle chains: 1/8 inch and 3/32 inch. The chainring, sprocket and chain should all be the same width. Although an 1/8-inch chain will work on a 3/32-inch chainring or sprocket, it is not ideal. A 3/32-inch chain will not work on a 1/8-inch chainring or sprocket. Because they do not need to shift from sprocket to sprocket, track chains use a full bushing to allow little flex and to be stronger. All bicycles with derailleur gears use bushingless chains which flex, making gear changing possible.

free websites