Keirin is a huge sport in Japan. Riders kit, components and bicycles are regulated making the racing solely physical ability and thus a huge betting sport in Japan. The Olympics doesn't see these regulations enforced and riders compete on top bikes wearing whatever helmets they want.
Chris Hoy has been chosen to ride the Keirin rather than defend his Sprint Olympic medals.
A mass start event conducted over eight laps of the track. The riders are paced by a derny (a small pedal motor bike), until around final 3 1/2 laps, at which point the pacer pulls off and the riders sprint for the finish.
The event starts with Round 1 heats. The winner progresses to the next round with 2nd and 3rd racing again in a repechages. The best 12 riders progressing to the second round. The top six riders go through from the second round to the final.
When to Watch
Men's Tuesday 7th August - Round 1 10.00, Round 2 16.34, Final 17.50