Motocross

A rider cornering during a motocross race in Australia

Motocross is a form of motorcycle or ATV racing held on enclosed off-road circuits and is the most popular form of amateur motorcycle racing. Motocross is derived from the French, and was originally called Scrambling when the sport was invented in the UK. The name "motocross" is a contraction derived from the words "Motorcycle" and "Cross Country". Motocross is often abbreviated as MX.

Motocross tracks are often quite large and incorporate natural terrain features with very few man made jumps, unlike Supercross, a sport that was originally derived from Motocross and is executed on a smaller track with more extreme man made obstacles. It is not unheard of for a Motocross track to be made up entirely of hills and turns with no jumps at all. Due to the size of the track, motocross races often include more than 40 racers whereas Supercross races are generally limited to about 25.

Outdoor motocross races usually use a two thirty-minute race formula of to determine a winner, where the two rankings in each race (or "moto") are added together and the lowest score wins the overall race. If there is a tie, then the racer who scored higher in the second of the day's races will be awarded the higher overall position.

Indoor, Supercross style races typically use a single twenty-minute race format where the winner is the first person to finish a predetermined number of laps. Quite often, prior to the main event there are a series of heat races to eliminate the slowest racers. The racers that place well in these heat races go on to compete in the main (or "final") event.

Machines

File:Motocross92.jpg

Motocross racing requires skill and a good sense of balance

Motocross motorcycles are lightweight and powered by highly tuned two-stroke or four-stroke engines (but usually geared for quick acceleration rather than very high speeds). They have knobby tires for traction on loose surfaces, a highly absorbent suspension designed to cope with the shock of heavy landings, and short gearing designed for swift acceleration rather than the ultimate in top speed. They often feature pedals and levers that are hinged so that they simply fold rather than bend or snap when the machine is inevitably dropped. Also the exhaust may be routed carefully so that a fall will not damage the exhaust, nor bend it so that it would obstruct the rear swing arm's travel - something that does happen to road bikes. The saddle is curiously shaped, in a long banana, to ride up over the front of the fuel tank so that the tank no longer protrudes. This is designed to allow the rider greater protection when he hits bumps or lands hard. However the main purpose of sitting up further on the gas tank is to keep the front wheel on the ground and aiming the bike where you want it, especially when exiting a turn. Lowering the rider's center of gravity greatly increases the ability to go through a turn at higher speeds. Sitting further back and accelerating hard over a series of bumps or ("whoops") keeps the front tire from dropping into any large gaps between them and causing you to loose control of the bike. The gyroscopic effect of the engine along with the wheels makes jumping the "motocross" bike over long distances possible - this effect keeps the bike from rotating through any axis other than the axis of the wheels while in the air. A common technique to change the attitude of the bike in air involves the use of the rear brake. When the rear wheel is decelerated while the bike is in mid-air, angular momentum is transferred from the wheel to the entire bike. This forces the front of the bike lower (and likewise, accelerating the rear wheel causes the front of the bike to rise), allowing the rider to force the bike to a specific position or attitude relative to the ground.

Unusual for racing machines, motocross bikes can be purchased in a ready-to-race condition at moderate prices from major motorcycle manufacturers.

Professional riders, however, modify their machines further, both for outright performance and to have the bike's behaviour more in tune with their own preferences. The highly tuned machines of the professionals are called "factory bikes." The latest trend in motocross motorcycles is towards four-stroke engines. New four-stroke machines rival the two-strokes in both weight and power and are significantly easier to use due to the smoother power delivery. These engines have been developed due to environmental concerns regarding the increased emissions of two-strokes. Some predict that two-strokes will not be available to buy after 2007, perhaps earlier in states such as California.

Engine sizes ranges from 50cc right up to 550cc, although bikes with sidecars can have up 1000cc engines. Four stroke motocrossers do not compete on a truly level playing field. Currently, 250cc four strokes compete in the 125cc class and 450cc four strokes are used in the 250cc class. They are very competitive in these classes but need twice the displacement to rival a two-stroke.

See also Motorcycle - especially the "Construction", "Dirt bike/Trail bike" and "Farm bike" sections

Manufactures

Incomplete list

Current

• Honda (Japan)
• Kawasaki (Japan)
• Suzuki (Japan)
• Yamaha (Japan)
• KTM (Austria)

The above five are the major five manufactures in most markets, the manufactures below command little market share (currently - 2005).

• Aprilia (Italy)
• TM (Italy)
• VOR (Italy)
• Vertametti (Italy)
• Husqvarna (Italy, ex Sweden)

Previous

• Cannondale (USA)
• Maico (West Germany)
• CCM (UK)
• Husaberg (Sweden)

See also the List of motorcycle manufacturers

Event

The object of the contest is to complete either a defined number of laps (usually three to five for amateurs, and 25 to 30 for professionals) or time period (anything up to 40 minutes) first. This competition is called a moto. Usually a race consists of two or three motos with the scores combined for an overall result.

Motocross racing is one of the most visually appealing forms of motorsport, with riders performing seemingly death-defying leaps, turns visibly at the edge of traction (as indicated by a sliding, spinning rear tire throwing dirt at all behind it), and the effort of riders clearly visible as they move their bodies around their motorcycles to balance the bikes for maximum speed.

Recently the sport has evolved with sub disciplines like Supercross and Arenacross (both are indoor motocross), Freestyle (or FMX) (a display of jumping skill rather than racing) and Supermoto (Motocross machines racing on both tarmac and off road).

Motocross can be an entry sport for motorsports in general. Classes for children as young as 4 years old exist for competition on 50cc machines.

ATVs

ATV's are enjoying a recent increase in popularity in the motocross scene. Due to a several ATV injuries and a number of high profile lawsuits, from 1989 to 1999 there was virtually no factory support for racing. The Yamaha Banshee was the only sport quad produced for that decade, and it received no updates either. For that decade, most quad racers purchased used Honda 250R's, a 250cc two-stroke race quad that Honda produced during the late eighties, ending production in 1989 to comply with a 10 year moratorium on sport quads, agreed upon by the major Japanese manufacturers. In 1999 Honda reentered the sport scene with a four-stroke quad, the 400EX. While not as fast and light as the 250R, with time and money it could be built into a formidable race quad. The 400EX began to dominate racing for the next five years until Yamaha released the YFZ450, a 450cc quad designed specifically for race use. The YFZ450 was immediately the best quad to buy for racing, as it could be very competitive straight off the factory floor. Eight months later Honda released their competition to the YFZ450, the TRX450R, another race ready stock bike for similar money.

Sidecars

Sidecar racing, known as Sidecarcross has been around since the 50’s but has declined in popularity since the 90’s. This variant is common in Europe, with a few followers in USA, New Zealand and Australia. Motocross sidecars are purpose built frames that resemble an ordinary motocross-cycle with a flat platform to stand on attached to either side and a handlebar at waist height to hold on to. The side of the "chair" (slang for the platform) usually follows the side of the road the nation in question drives upon, but not always. The passenger balances the bike by being a counterweight, especially in corners and on jumps. It’s driven on ordinary crosstracks. It is very physically demanding, especially for the passenger. This is reflected in most in the Swedish term for passenger- "burkslav", roughly translated as trunk/body/barrel-slave. This name comes from the early sidecars where the platform looked like a real road-sidecar and not todays platform.

The major frame builders today (2004) are VMC, BSU, AYR, EML and Woodenleg. Ordinary engines can be used, but size matters and two engines purpose built for sidecars exist, Zabel (Germany) and MTH (Austria) are most common. Fourstrokes are getting more common, usually KTM(Austria).

Freestyle

Mike Adair performing the Superman Seatgrab

Freestyle motocross (FMX), a relatively new sport, is not racing and concentrates on performing acrobatic stunts while jumping these motorcycles. The winner is chosen by a group of judges. The riders are scored on style, level of trick difficulty (the most difficult trick being done at this time is a body varial 360, also called the Carolla, done by Chuck Carothers, successfully performed at the 2004 X games best trick competition. Prior to this, it was a backflip 360, or off-axis backflip), best use of the course, often times crowd reactions as well. Caleb Wyatt was the first person to successfully execute a backflip on a large bike.

Minibikes

The latest craze is adult racing on miniature (50cc) motorcycles called a minibike. These inexpensive minibikes designed for small children are often transformed for adult use by adding taller handle bars and by improving the suspension.

Supermoto

Supermoto is a recent invention involving racing Motocross bikes on a part concrete, part off road track, with "road" tires instead of off road tires. Some tracks for these race events have jumps, berms, and whoop-dee-doos just like true motocross tracks. For special events, the Supermoto track may incorporate metal ramps for jumps that can be disassembled and taken to other locations. Supermoto races may take place at modified go-kart tracks, road racing tracks, or even street racing tracks. There are also classes for kids such as the 85cc class.

Governing bodies

The sport is governed world wide by the FIM, with federations in many nations.

Incomplete listing

• USA - AMA
• UK - ACU, with other separate (unconnected) bodies like the AMCA, ORPA, BSMA, and YSMA.
• Ireland - MCUI (covering the whole island)
• France - FFM
• Canada - CMRC / CMA
• South Africa - MSA

External links

• American Motorcyclist Association
• Auto-Cycle Union (UK)
• Motosport South Africa
• Fedaration Of International Motocross