found: Wikipedia, Mar. 26, 2012:Bicycle racing (Bicycle racing is a competition sport in which various types of bicycles are used. There are several categories of bicycle racing including road bicycle racing, cyclo-cross, mountain bike racing, track cycling, BMX, bike trials, and cycle speedway.) Bicycle motocross (Bicycle motocross or BMX refers to the sport in which the main goal is extreme racing on bicycles in motocross style on tracks with inline start and expressive obstacles, and it is also the term that refers to the bicycle itself that is designed for dirt and motocross cycling.) BMX racing (BMX racing is a type of off-road bicycle racing. The format of BMX was derived from motocross racing. BMX bicycle races are sprint races on purpose-built off-road single-lap race tracks. The track usually small a starting gate for up to eight racers, a groomed, serpentine, dirt race course made of various jumps and rollers and a finish line. The course is usually flat, about 15-foot (4.6 m) wide and has large banked corners that help the riders maintain speed.)
