Motocross (often shortened to MX or MotoX) 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 Scrambles, which were themselves an evolution of Trials events popular in northern Britain. The first known Scramble took place at Camberley, Heath in 1924 [4]. European motorcyclists adopted the event and gave it a slight makeover, shortening the tracks and adding laps and a few man-made obstacles like jumps. 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 1950s.

In 1952 the FIM, motorcycling’s international governing body, created an individual European Championship using a 500cc engine displacement formula. In 1957, it was upgraded it to World Championship status. In 1962, a 250cc world championship was created. It was in the smaller 250cc category that companies with two-stroke motorcycles came into their own. Companies such as Husqvarna from Sweden, Bultaco from Spain, CZ from Czechoslovakia and Greeves from Britain, became popular due to their lightness and agility. By the 1960s, advancements in two-stroke engine technology meant that the heavier, four-stroke machines were relegated to niche competitions. Riders from Belgium and Sweden began to dominate the sport during this period.

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 250cc 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 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.

Event

Motocross is distinct from other forms of motorsport in having a mass start, where all the riders line up alongside each other, starting simultaneously and racing the race distance, with the first rider across the finish line the winner.

Motos vary in duration, usually measured in time elapsed plus one or two laps, or alternatively a fixed number of laps. Top level racing tends to have long races (e.g. 30 minutes plus 9 laps) while at the other end of the spectrum, amateur races can be as short as 5 minutes. When the designated time duration of the race is complete, a finish line flagger signals via a board or flag to the racers that there is one or two laps left, and the race is finished by a checkered flag.

Motocross tracks are often quite large ( a quarter mile) and incorporate natural terrain features with varying amounts of man made jumps and other features. It is not unheard of for a Motocross track to be made up entirely of hills and turns with no jumps at all. In contrast Supercross is an entirely man made track, comprising almost exclusively of a wide array of jumps and typically held in an indoor stadium. Due to the size of outdoor tracks, motocross races typically include 40 racers and supercross races usually have about 20 riders.

Contrasting with motocross are the off-road racing events of Enduro, Hare and Hounds, Hare Scrambles, etc. In these events there are a predetermined number of laps or long distance loops to complete within a maximum time limit. These events, unlike Motocross, race on courses that are largely comprised of natural terrain. The Baja 1000 is an example of one of these types of events. Also, events like Competitive Edge and Ocotillo Wells offer as many offers as the offer offers.

Major Competitions

The world is dominated by two main Motocross series; the FIM's Grand Prix - the World Championship series and the AMA's American National Championship.

The AMA Motocross Championship (the "outdoor series") season begins in early May and continues until mid-September, and consists of 12 rounds at 12 major tracks all over the continental United States. There are two classes; "Motocross" and "Motocross Lites". Each round has two motos of 30 minute-plus-two-laps, per class, held approximately two hours apart.

The Grand Prix (or Motocross World Championship) is predominantly held in Europe with some "flyaway" rounds, recently in South Africa and Japan, but over its history it has visited numerous countries including; Indonesia, Australia and countries on both American continents. There are two classes; MX1 and MX2 (analogous to "Motocross" and "Motocross Lites" respectively). Race duration is slightly longer at 35 minutes plus two laps, while the series is longer, generally incorporating over 16 rounds.

The annual Motocross des Nations (generally left untranslated from French, but more recently referred to as Motocross of Nations) is usually held at the end of the year when National and World Championship series have ended. The format involves teams of three riders representing their nations. Each rider competes in a different class (MX1, MX2 and "Open"). There are three motos with two classes competing per moto. The location of the event changes from year to year. The United States, Belgium and Great Britain have had the greatest success. France has had a very succesfull yaer in the las Motocross of nations.

Machines

Solo machines have engines ranging in displacement size from 50cc to 650cc. In the early years of motocross, the 500cc class was considered the premier division. However, as technology progressed, the open class bikes became more powerful and fewer riders were able to ride them at their limits. The 250cc bikes also became faster with newer technology and were more manageable thus, they eventually superseded the 500cc bikes and became the premier class.

The most common distinction between motocross machines is whether they have two-stroke or four-stroke engines. Originally all bikes were four-stroke (in the Pre-65 era), but as the two-stroke engine improved they became more popular with their domination of the sport in the 1970s, 80s and 90s. The two-stroke engine produced more power than a four-stroke engine of the same capacity (cc), however oil must be introduced into the crankcase space for con-rod bearing lubrication, either with a pump or by mixing it with the petrol; this oil is burnt, giving the characteristic smell of a two-stroke engine. Four-stroke continued to be raced in specialist classes throughout this period, partially in the 500cc class. During the early 1980s another wave of technological advancement saw the typically two-stroke air cooled, twin shock rear suspension machines replaced by machines that were water cooled and fitted with monoshock rear suspension. This created even more powerful machines within the existing displacement categories (125,250 and 500cc).

The late 1990s saw an environmental crackdown on two-stroke engines particularly in the large American market. This spurred the development of environmentally friendlier four-stroke engines. While producing less power for the same displacement, four-strokes typically burn the fuel in a cleaner fashion. A major drawback of this is that four-strokes produce a deeper sound compared to two-stroke, which has led to a sharp rise in sound complaints across the world. To make the four-stroke competitive the world sanctioning body amended the displacement categories so that a 125cc two-stroke would compete against a 250cc four-stroke, and a 250cc two-stroke would compete against a 450cc four-stroke. By this point, the 500cc class had been dying out due to their immense power permitting fewer riders with enough talent to ride them at their limits. Yamaha introduced the first "modern" four-stroke with the YZ400F, which was soon succeeded by the YZ426F and then by the "standard" 450cc machine. Other manufacturers soon followed suit, downplaying their 250cc two-stroke bikes. As development progressed the power output of these bikes superseded their two-stroke equivalents, further sealing their fate. The four-stroke revolution continued with a wave of 250cc four-stroke machines to compete against the 125cc two-strokes. Once again manufacturers have been quick to promote these machines against their 125cc two-stroke equivalents. In the summer of 2006 Honda launched the CRF150R to compete in the 85cc class. This required sanctioning bodies to make further rule changes, which are very contentious with fans of two strokes.

For 2008 the MX2 class in amateur racing allowed 144cc two-stroke bikes to race against the 250 four-stroke bikes. This was to encourage more riders into the sport as two-stroke bikes are much more cost effective than four-stroke bikes. In AMA amateur racing two-stroke up to 153cc are allowed to race. But some countries like the UK only allow factory made or bored out 125's up to 144cc.

In professional racing 144cc machines are allowed but they have to be produced as 125's and then bored out to 144cc. This is to deter professionals riding from two-stroke bikes.

Riders are often (but not always) classed according to their machine's engine size. Common classification includes;

Youth racing included the MX2 class through to Autos, Adults ride MX2 through MX1 to MX3.

Motocross machines have extensive suspension to enable riders to tackle large jumps and ride at speed over the rough terrain. The advent of improved suspension transformed motocross from its scrambling origins with natural track to the current form today, with multiple jumps that would have previously been impossible.

To bring the weight down to an acceptable level (usually 200 to 250 lbs for full-size machines), items such as speedometers, lights, kickstands, electric starters, etc. are omitted. Lightweight materials such as aluminum and magnesium are commonly used as original equipment from the factory or sold in the after-market.

Because of the physical nature of motocross, riders spend much of their time standing to absorb shock with their knees. The long, flat seat is designed to allow riders to shift their weight quickly to provide more traction in corners, rather than for comfort.

Unusually for racing machines, motocross bikes can be purchased in a ready-to-race or nearly ready-to-race condition at moderate prices from major motorcycle manufacturers. Many riders, however, modify their machines further, both for outright performance and to have the bike's behavior more in tune with their own preferences or just for enjoyment.