The beauty of the track bike lies in its simplicity. These bikes have no brakes and only run on single speed gears.
The rear sprocket is screwed onto the rear hub and is not able to freewheel like the cassettes on a road bike. This is called the fixed cog system. Most riders run 1/8th inch chains similar to the ones used on BMX bikes. These are for strength.
Gear ratios are changed by either changing the rear sprocket or the front chain ring. A set of three consecutive chain rings e.g. 47,48 and 49 or 50, 51 and 52 should cover most gear ratios combined with for instance a 14, 15 & 16T rear sprocket set (refer to ratio chart in archive).
Riders ride slower or accelerate by changing their pedal cadence.
Most top track riders ride on tubular tires. These tires consist out of an outer casing made of a rubber running surface and a material part that is glued onto the tubular compatible rim. The inner inflatable casing is made of thin latex. Some “tubbies” can be inflated to 200PSI and only weigh 135g each. These days high pressure tires and tubes are widely used on track bikes.
Entry level chromoly bikes are available at fair rates. Aluminium is widely used in frame construction and depending on the quality used one can find very good bikes. Some of the top riders in the world ride monocoque carbon frames. These are the most expensive.
However one can find a second hand track bike for a good price.