BMX

BMX, short for bicycle motocross, is a cycling discipline that involves riding specialized small-wheeled bikes over short, purpose-built courses or performing tricks on various terrains. It encompasses both racing on closed tracks and freestyle riding on streets, parks, and dirt jumps.

Originating in the early 1970s in Southern California, BMX began when youth copied motocross on rugged bicycles. The sport evolved quickly, leading to purpose-built BMX bikes with small frames, 20-inch wheels, a single gear, and strengthened components. As tracks and contests developed, two main branches emerged: BMX racing and BMX freestyle.

BMX bikes are typically 20-inch wheel bikes for race and most freestyle riding, with 24-inch cruiser variants used by some riders. Frames are strong and lightweight, and many bikes use a rear U-brake; front brakes are less common on race bikes. A gyro or detangler allows bar spins without tangled cables. Pegs enable tricks on rails and ledges.

Racing discipline focuses on speed and precise line choice on a track with tabletop jumps, rhythm sections, and jumps. Freestyle involves tricks on ramps, rails, and flat ground, and includes substyles such as park, street, and dirt jumping. BMX has grown into a global sport with major events and professional riders.

Governance and competitions include the UCI BMX World Championships and national bodies such as USA BMX. BMX racing has been an Olympic discipline since 2008; BMX freestyle was added for the Tokyo 2020 Games.