What does the bicycle racing abbreviation BMX originally stand for?

BMX originally stands for bicycle motocross.

The abbreviation describes a style of bicycle racing inspired by motocross motorcycle competition. BMX developed in California during the early 1970s, when children and teenagers began racing modified bicycles on dirt tracks with jumps, berms and other features modeled on motorcycle courses.

The sport quickly spread beyond California and became organized internationally. BMX racing was added to the Olympic program at the 2008 Beijing Games, while BMX freestyle later joined the Olympics at Tokyo 2020, held in 2021.

BMX can refer both to the bicycle category and to several disciplines. Racing uses compact bikes and a start hill, whereas freestyle emphasizes tricks and movement in parks, on ramps or in street settings. The original expansion refers to the racing inspiration, not to a particular bicycle brand or technical component.