Motocross rider hitting the rough side of a corner Motocross is a form of motorcycle sport or all-terrain vehicle racing held on enclosed off road circuits. Motocross is derived from the French, and traces its origins to British Scrambling competitions. The name "motocross" is a portmanteau derived from the words "motorcycle" and "Cross Country".

History

Motocross was first known as a British off-road event called scrambling, which were themselves an evolution of Trials events popular in northern Britain. The first known Scramble took place at Camberley, Surrey in 1924. During the 1930s, the sport grew in popularity, especially in Britain where teams from BSA, Norton, Matchless, Rudge, and AJS competed in the events. Off-road bikes from that era differed little from those used on the street. Intense competition over rugged terrain led to technical improvements in motorcycles. Rigid frames gave way to suspensions by the early 1930s, and swinging fork rear suspension appeared by the early 1950s, several years before it was incorporated on the majority of production street bikes. The period after the Second World War was dominated by BSA which had become the largest motorcycle company in the world. BSA riders dominated international competitions throughout the 1940s.

By the late 1960s, Japanese motorcycle companies began challenging the European factories for supremacy of the motocross world. Suzuki claimed the first world championship for a Japanese factory when it won the 1970 250 cc crown. Motocross also began to grow in popularity in the United States during this period, which fueled an explosive growth in the sport. The first stadium motocross event was held in 1972 at the Los Angeles Coliseum. In 1975, a 125cc world championship was introduced. European riders continued to dominate motocross throughout the 1970s but, by the 1980s, American riders had caught up and began winning international competitions.

During the early 1980s, Japanese factories presided over a technology boom in motocross. The typically two-stroke air cooled, twin shock rear suspension machines gave way to machines that were water cooled and fitted with monoshock rear suspension. By the 1990s, increasingly stringent environmental laws in California forced manufacturers to develop environmentally friendly four-stroke technology. At the turn of the century, all the major manufacturers have begun competing with four-stroke machines. European firms also experienced a resurgence with Husqvarna, Husaberg and KTM winning world championships with four-stroke machinery.

Recently, the sport has evolved with sub-disciplines such as stadium events known as Supercross and Arenacross held in indoor arenas. Freestyle (or FMX) events where riders are judged on their jumping and aerial acrobatic skills have gained popularity, as well as Supermoto (Motocross machines racing on both tarmac and off road). Vintage motocross events have also become popular with riders competing on bikes usually pre-dating the 1975 model year.