You don’t have to worry about shifting gears on a track bike, but you do have to worry about slipping cogs, as this keirin rider found out. Keirin is a form of track racing in which riders sprint for the win after following a motorized pacer bike.
Its roots date back to 1948, when the sport was created as a gambling event. Although it eventually caught on outside of Japan, it only became an official Olympic event at the 2000 Olympics in Sydney, Australia. Races are typically 1.5 km, which is six laps on a 250 m track. The format is simple: the pacer begins at 30 km/h then increases to 50 km/h for the third lap. The riders are constantly jockeying for position at this point, trying to get the best spot before the racing really begins. The pacer leaves the track at 750 m and then all Hell breaks loose for the riders.
In Japan, going to a keirin race is much like going to a horse or dog race…except it’s people on bikes. The races there start with the riders riding to the start line as a group, bowing both as they enter the track and then as they place their bikes on the start line. Furthermore, each racer wears an easily identifiable coloured jersey and number so it’s easy for the gamblers to place their bets.
In the video below, you can see the rider on the far right veer quickly to his left, knocking over the rider in the yellow. Watching the clip, it appears that his cog might not have been tightened to the wheel, which causes him to slip and zigzag. It’s also possible that the rider stripped the threads.