The UCI Track Cycling World Championships are the set of world championship events for the various disciplines and distances in track cycling. They are regulated by the Union Cycliste Internationale. Before 1900, they were administered by the UCI's predecessor, the International Cycling Association (ICA). Current events include: time trial, keirin, individual pursuit, team pursuit, points race, scratch race, sprint, team sprint, omnium and madison. Women's events are generally shorter than men's. Events which are no longer held include the motor paced events and tandem events. From Wikipedia
