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 widely considered the world's most popular form of 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.

Professional races measaured by time. A typical Pro race will run for 30 minutes, then once the leader crosses the finish line that lap, he is given a signal indicating there are two laps remaining. A one-lap-to-go signal is given at the start of the final lap, and the race is completed at the end of that lap. This format is known as 30 minutes plus 2 laps.

Other formats may be determined by laps. In each race there is a set number of laps and the first rider to complete the set number of laps is the victor. The first three riders that finish first are declared the podium riders because of the first though third positions in the race. Races are ran in sessions called motos. There are two motos in a race and the riders place in those heats are averaged together to get their overall finish.

Machines

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 high top speed. They feature hinged footpegs and levers 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 (seat) is curiously shaped, in a long banana, to extend from rear of the fuel tank to the rear fender. This offers the rider greater protection when he or she hits bumps or lands hard and allows the rider to move and distribute his or her weight over the front or rear of the bike. This will affect rotation pitch while jumping and greater traction to the front wheel when necessary on the ground. Lowering the rider's center of gravity (sitting) 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 lose 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. Although the four-strokes weigh more, they have much more power to back up the weight. These engines have been developed due to manufacturer's pressure and environmental concerns regarding the increased emissions of two-strokes. Some predict that two-strokes will not be available to buy after 2008, 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. However, the popularity of four-stroke motocross bikes has been steadily increasing. Due to the increase in popularity and to non-matching displacements of four-stroke and two-stroke motorcycles in the same classes, in the year 2005 the AMA changed the class names from 250cc to Pro, and from 125cc to Pro Lite. Thus, the former 125cc Supercross series is now referred to as AMA Supercross Pro Lites; the 250cc Motocross series is now AMA Motocross Pro; etc.

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

Manufacturers

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).

  • Husaberg (Sweden)
  • Aprilia (Italy)
  • TM (Italy)
  • VOR (Italy)
  • Vertemati (Italy)
  • Husqvarna (Italy, ex Sweden)

Previous

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


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 seven for amateurs, more for professionals) or fixed 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 to determine the 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.

Motocross racers spend a lot of time airborne!

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.

Physical demands

One of the least understood aspects of motocross racing by non-participants is the extreme level of physical fitness required of competitors. Those unfamiliar with the sport often assume that the rider is doing nothing more strenuous than steering a motorized vehicle around a field, no more demanding than driving the family car around the block. In truth, motocross racing has been found to be one of the most physically demanding sports in existence. Observing in detail a rider's actions while at speed on the track reveals why. He or she must maintain ultra-precise control of a machine traversing terrain that most people would have difficulty walking across while maintaining as high of a rate of speed as possible. The rider is astride a machine weighing at least two hundred pounds and, at the most elite professional level, has an engine that produces at least fifty horsepower. A rider's arms and legs are in constant motion during a race, fighting for control of the motorcycle and absorbing the energy produced by high-speed landings from heights that often exceed twenty feet or from two-foot high stutter bumps (called whoops) that jackhammer the motorcycle and the rider. The G forces produced test the absolute limits of a rider's strength and endurance. Finally, a typical professional moto (heat race) lasts at least thirty minutes. That represents half of an hour in which the faster the rider goes, the more violently and frequently he or she is punished. And there are no pauses, breaks or pit stops. At least not if a rider expects to win. [citation needed]

The National Sport Health Institute in Englewood, California tested several professional motocross racers in the early 1980s as part of a comparative study of the cardio-vascular fitness of athletes from various disciplines. Athletes from track, American football and soccer were tested, among others. The cardiac stress and strength test results compiled there revealed that the motocross subjects had as high of a fitness level as than any other discipline tested. (original article appeared in DirtBike magazine in 1980. Interview with Brad Lackey, World Motocross Champion and one of the test's participants appeared in Racer X Illustrated in 2004 and is recounted here)

ATV Motocross

Starting in the year 2002, ATV motocross started to see a dramatic increase in participation across the United States. This was a direct result of the major ATV manufacturers getting involved in the sport. Before we can talk about the current state of ATV motocross, we must understand the past. ATV motocross floundered after Honda, Kawasaki, Suzuki and Yamaha dropped ATV-racing support in the mid 1980s due to the bad publicity of the vehicles. Throughout the late 1980s and all during the 1990s, aftermarket companies kept the sport alive, but barely. Racers would build expensive, custom ATVs with parts from major aftermarket manufacturers like Laeger's, Walsh Race Craft and Lonestar Racing. The engine that kept racing alive was the Honda TRX250R engine that was manufactured from 1986 to 1989. Again, the aftermarket helped racers get all they could out of the dated engine. Companies like Curtis Sparks Racing Engines, Baldwin Motorsports and Hinson Racing made it so the only stock component of the 250R engine were the left and right engine cases. Suspension upgrades made it possible for ATVs to hit jumps never thought possible. Suspension companies like PEP and Custom Axis, combined with long-travel A-arms and rear suspension links smoothed out rough tracks and harsh landings.

However, in order to be competitive on the motocross track, it was necessary to spend upwards of $20,000 on the race ATV. In the late 90s, rules were changed to allow racers to use dirt bike engines in ATV frames. The era of the four-stroke hybrid race ATV was born when Harold Goodman piloted a custom-built YZ400F to a national Four-Stroke Pro-Am championship. Soon hybrid machines were all over the tracks.

The manufacturers started paying closer attention to the sport ATV market, and in 1999 Honda released the four-stroke TRX400EX. While it wasn't as powerful as the hybrids racing on the tracks, it was a positive step. In 2001, Cannondale entered the ATV market and even fielded an ATV racing team in partnership with Nac's Racing the following year. The Cannondale story was a short one as the company declared bankruptcy shortly after 2002. In 2003 Suzuki released the LT-Z400 that featured a liquid-cooled four-stroke powerplant. That same year, the ATVA instituted a Pro Production class at the motocross nationals in order to showcase "stock" ATVs. The traditional Pro class still allowed two-strokes and hybrids. Many Pro racers raced both classes, but the premier class was still the Pro class. Tim Farr, in a move that raised eyebrows, raced only the Pro Production class. Doug Gust won the Pro Production class while Jeremiah Jones won the Pro class. Jones' championship would be the last Pro-class championship on a two-stroke.

Late in the 2003, Yamaha announced the YFZ450 for the 2004 model year. This ATV represented the first time a major manufacturer built a high-performance sport ATV suited for racing. While it wasn't as wide as many wanted for motocross and didn't have long-travel suspension, it featured a four-stroke engine very similar to the motocross dirt bikes Yamaha was putting out. The ATV also came stock with fully adjustable front suspension, the first time this was available on a stock ATV. After the Yamaha announcement, Honda announced it was going to bring the TRX450R to market in 2004. The tide was turning for the high-performance race ATV market.

The 2004 national motocross season was one of the most anticipated in 15 years. Suzuki announced it was going to hire Doug Gust as its motocross pilot, Honda was hiring Tim Farr as its factory racer and Yamaha was going to offer support Kory Ellis in limited fashion for the season. This represented the first time since around 1986 that any manufacturer was offering factory support for ATV racing. The moved proved to be a successful one for Suzuki as Doug Gust walked away with the national motocross championship, and in the process winning six overalls in a row.

The 2005 season saw more factory support and Suzuki fielding two racers, Gust and Jeremiah Jones, out of the Yoshimura/Suzuki semi. That year it was Honda winning the championship with support rider John Natalie taking the motocross championship. The 2005 season proved that the factories were willing to support ATV racing as they never had before. With that support on the track also meant support in the dealerships in the way of new, updated machines.

In the summer of 2005, Suzuki announced it was going to produce the 2006 LT-R450. This sport ATV was the most motocross-ready ATV ever produced. It featured electronic fuel injection, a high-performance four-stroke engine and a chassis that could be competitive in stock form. The front end had high-end shocks with 10 inches of travel and a width approaching 50 inches. The rear tires with 18-inch tires just like motocrossers sport. The swingarm was made of steel, too.

In 2005, local tracks mirrored the national tracks as more and more racers were bringing ATVs to race thanks to raceable models. Many feel that 2006 will be the biggest yet as the nationals continue to grow and many local AMA districts are offering "quad-only" race weekends.

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 today's 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 instead concentrates on performing acrobatic stunts while jumping motocross bikes. The winner is chosen by a group of judges. The riders are scored on style, level of trick difficulty, best use of the course, and frequently crowd reactions as well.

One stunt performed is the backflip, which was first performed successfully on a large bike by Caleb Wyatt. Some consider the body varial 360 as the most difficult stunt being performed at this time. This stunt, also called the Carolla, was first performed by Chuck Carothers at the 2004 X Games. Prior to this, the backflip 360, or off-axis backflip, was widely considered the most challenging stunt.

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.

In 1998 Australian minibike riders Jonathan Byrne and Nicholas Stephenson revolutionised the sport by launching them from a up ramp to a down ramp while copying the mid air monuvers done on a large bike in freestyle motocross. This type of minibiking is now called freestyle minibike riding. Since 1998 this type of sport has spread all over the world. [citation needed]

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
  • Sweden - SVEMO

This page about Motocross includes information from a Wikipedia article.
Additional articles about Motocross
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Incomplete listing. This version is rumoured to be released in 2006. The sport is governed world wide by the FIM, with federations in many nations. Recent signtings of the mk 4 suggest that it will be more in line with the mk 2 as the size of the car has once again increased. There are also classes for kids such as the 85cc class. However, the MR2 was discontinued after the 2005 model year. Supermoto races may take place at modified go-kart tracks, road racing tracks, or even street racing tracks. There was speculation that the 2005 model could be a hybrid car.

For special events, the Supermoto track may incorporate metal ramps for jumps that can be disassembled and taken to other locations. Many had hoped that Toyota would continue MR2 production because the leap along the price-axis to the next alternatives (Porsche Boxster, Lotus Elise and Exige, Honda NSX) is so large that many enthusiasts would have to settle for a front-engined car, should the MR2 be discontinued. Some tracks for these race events have jumps, berms, and whoop-dee-doos just like true motocross tracks. Toyota is cutting down its selection of sports cars and replacing them with less aggressive "sports packages" offered on their more sedate cars. 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. For two decades, the MR2 has been a delight to car enthusiasts around the world, offering an affordable way to experience the marvellous handling of a mid-engine sports car. [citation needed]. [4] The ZZW30 sold just 7,233 units in its debut year, falling to 6,254 in 2001 and 4,705 in 2002.

Since 1998 this type of sport has spread all over the world. In July 2004, Toyota announced that the MR2 would be discontinued in the US at the end of the 2005 model year because of increasing competition and lack of sales. This type of minibiking is now called freestyle minibike riding. For 2004, the body was strengthened, adding 10 kg to the vehicle's weight. In 1998 Australian minibike riders Jonathan Byrne and Nicholas Stephenson revolutionised the sport by launching them from a up ramp to a down ramp while copying the mid air monuvers done on a large bike in freestyle motocross. The suspension was uprated with new springs and shock absorbers and a brace was added to the bottom of the car to improve rigidity. These inexpensive minibikes designed for small children are often transformed for adult use by adding taller handle bars and by improving the suspension. The rear wheels were increased to 16" while the front ones remained 15", and both transmissions received an additional gear.

The latest craze is adult racing on miniature (50cc) motorcycles called a minibike. The air intakes on the sides of the car were now color coded and the interior was modified with new seats and a gauge cluster. Prior to this, the backflip 360, or off-axis backflip, was widely considered the most challenging stunt. For 2003, the ZZW30 received some exterior changes, including a new front bumper, front and rear lights, a new rear grille, and the computer also received an upgrade allowing the gears to change and engage much quicker than the pre-2003 models which were equipped with the sequential transmission. This stunt, also called the Carolla, was first performed by Chuck Carothers at the 2004 X Games. The MR-S was originally introduced in October of 1999 and received a sequential transmission in August 2000. Some consider the body varial 360 as the most difficult stunt being performed at this time. Although it lost, the ZZW30 proved the top-class handling abilities of the ZZW30.

One stunt performed is the backflip, which was first performed successfully on a large bike by Caleb Wyatt. However, the driver of the ZZW30, Manabu Orido, allowed the other vehicles (a much higher powered S15 Silvia, S14 Silvia, and Amuse S2000) to catch up and ended in the ZZW30 losing to the much quicker S15 Silvia. The riders are scored on style, level of trick difficulty, best use of the course, and frequently crowd reactions as well. Turbo", the Techno Spirits ZZW30, outdrove several more powerful cars. The winner is chosen by a group of judges. During a comparison test during a Japanese motorsports show, "NA vs. Freestyle motocross (FMX), a relatively new sport, is not racing and instead concentrates on performing acrobatic stunts while jumping motocross bikes. Although some complained of the relative lack of power the vehicle had, many owners have recently discovered a way to switch out the 1ZZ-FE engine in exchange for the 2ZZ-GE, bringing up the power to 190 hp, drastically bringing up the accelerating properties of the ZZW30.

Fourstrokes are getting more common, usually KTM(Austria). For example, Tiff Needell, a very experienced race driver and the former host of the BBC TV show Top Gear, praised the handling of the ZZW30. Ordinary engines can be used, but size matters and two engines purpose built for sidecars exist, Zabel (Germany) and MTH (Austria) are most common. The ZZW30 is considered to be the best-handling MR2. The major frame builders today (2004) are VMC, BSU, AYR, EML and Woodenleg. All agreed, however, that the ZZW30 had nearly perfect handling, allowing one to brake into corners and throw the car through the corner in slight drift. This name comes from the early sidecars where the platform looked like a real road-sidecar and not today's platform. The feedback for the new model was somewhat mixed - others liked its return to the AW11's design concept, while the fans of the SW20 would've liked it to continue along the path of the previous model.

This is reflected in most in the Swedish term for passenger- "burkslav", roughly translated as trunk/body/barrel-slave. In addition to the 5-speed manual transmission, a sequential transmission controllable from the steering wheel was also available. It is very physically demanding, especially for the passenger. The 140 hp (104 kW) maximum power was quite a drop from the SW20 GT, but thanks to the lightness of the car it could move quite quickly, accelerating from 0 to 100 km/h in 7.5 to 7.9 s. It’s driven on ordinary crosstracks. Unlike its predecessors, however, the engine was placed onto the car the other way round, making the exhaust manifold point towards the rear of the car. The passenger balances the bike by being a counterweight, especially in corners and on jumps. The intake camshaft's timing was adjustable via the VVT-i system, which was introduced earlier on the 1998 SW20.

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. Like its predecessors, the engine used dual overhead camshafts and 16 valves. 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 engine of the ZZW30 was the brand-new all-aluminium 1ZZ-FE, a 1794 cc I4. This variant is common in Europe, with a few followers in USA, New Zealand and Australia. Toyota changed the American name to "MR2 Spyder" reportedly because the idea of a car with the nickname of "Mrs." would sound funny. Sidecar racing, known as Sidecarcross has been around since the 50’s but has declined in popularity since the 90’s. In Japan, the car is called the MR-S, which purportedly is derived from the forementioned designation.

Many feel that 2006 will be the biggest yet as the nationals continue to grow and many local AMA districts are offering "quad-only" race weekends. The biggest change was, however, the replacement of either the solid or targa top with a convertible soft top, giving the car the 'Spyder' designation. In 2005, local tracks mirrored the national tracks as more and more racers were bringing ATVs to race thanks to raceable models. The new MR2 was, in a way, return to the design concept of the AW11 since the weight of the car was once again dropped below a metric ton and it was significantly smaller than the SW20. The swingarm was made of steel, too. After having been in the market for almost ten years, the SW20 had to move aside as Toyota released the new MR2, designated ZZW30. The rear tires with 18-inch tires just like motocrossers sport. Very little is known about these cars outside of Japan.[3].

The front end had high-end shocks with 10 inches of travel and a width approaching 50 inches. The car track width is extended and body dimensions dramatically changing the cars overall visuals, giving the car a "supercar" look, and also better handling and weight reduction. It featured electronic fuel injection, a high-performance four-stroke engine and a chassis that could be competitive in stock form. In many respects the extended body can be compared to that of a Porsche Turbo widebody. This sport ATV was the most motocross-ready ATV ever produced. It is unknown how many original (non factory replica) cars still exist today. In the summer of 2005, Suzuki announced it was going to produce the 2006 LT-R450. This makes these officially built TRD2000GTs the rarest of all MR2s and ultimately the most sought after and difficult to find.

With that support on the track also meant support in the dealerships in the way of new, updated machines. Only 3 complete cars are known to have been shipped into Europe with only 10 complete kit conversions allocated to TRD USA for the entire American market. The 2005 season proved that the factories were willing to support ATV racing as they never had before. TRD Japan never sold body parts for third-party conversion separately (except rear wing), they transformed complete cars. That year it was Honda winning the championship with support rider John Natalie taking the motocross championship. Some cars left the factory boasting up to 500 PS (493 hp/368 kW) and less than 1100 kg (2425 lb) for a very impressive power to weight ratio. The 2005 season saw more factory support and Suzuki fielding two racers, Gust and Jeremiah Jones, out of the Yoshimura/Suzuki semi. Virtually every car converted also had other TRD parts fitted too including extensive changes to both the suspension and engine.

The moved proved to be a successful one for Suzuki as Doug Gust walked away with the national motocross championship, and in the process winning six overalls in a row. All official TRD2000GT's had a 60 mm (2.4 in) wider front and rear track which improved handling considerably over the original suspension design. This represented the first time since around 1986 that any manufacturer was offering factory support for ATV racing. Each official car converted was made using lightweight fibreglass components (in place of heavy steel original parts, front wings/fenders, boot lid, rear quarter panels, front and rear bumpers, etc.) and re-classified as completely new cars (with their own specially numbered TRD vin plate rivited to the body to indicate their authenticity and rarity). Suzuki announced it was going to hire Doug Gust as its motocross pilot, Honda was hiring Tim Farr as its factory racer and Yamaha was going to offer support Kory Ellis in limited fashion for the season. In order to ensure exclusivity, a high price tag was charged and total of just 35 factory car conversions where completed by Toyota Technocraft Ltd. The 2004 national motocross season was one of the most anticipated in 15 years. Toyota also did the same with their Supra Twin Turbo model, offering a conversion service to transform these cars into a TRD3000GT[2].

The tide was turning for the high-performance race ATV market. This was to pay homage to the wins by their TRD2000GTs in the GT-C Japanese racing series, the TRD2000GT racing series cars where based on the SW20 floorpan. After the Yamaha announcement, Honda announced it was going to bring the TRX450R to market in 2004. In 1998, Toyota Racing Development [1] offered an official kit body conversion and tuning programme for Japanese Domestic Market (JDM) owners to transform their existing SW20 MR2 into a widebody TRD2000GT kit replica car. The ATV also came stock with fully adjustable front suspension, the first time this was available on a stock ATV. Some of these V6 MR2 owners have claimed to have been able complete the swap within the price range of $2,500 USD without the labor. While it wasn't as wide as many wanted for motocross and didn't have long-travel suspension, it featured a four-stroke engine very similar to the motocross dirt bikes Yamaha was putting out. The 1MZFE motor that comes from the V6 powered Solara and Camry, has quickly become a popular modification as it is relatively cheap and easy to modify to.

This ATV represented the first time a major manufacturer built a high-performance sport ATV suited for racing. The SW20 has become a major collector's car since the 2003 Ultimate Street Car Challenge win of Brad Bedell and his yellow V6-powered MR2. Late in the 2003, Yamaha announced the YFZ450 for the 2004 model year. All models also received new wheels, optional Recaro seats, and a three-way adjustable rear spoiler. Jones' championship would be the last Pro-class championship on a two-stroke. This, and some other changes improved the engine's power output to a respectable 198 hp (148 kW). Doug Gust won the Pro Production class while Jeremiah Jones won the Pro class. While the turbocharged engine remained the same, in JDM models the normally aspirated 3S-GE engine was equipped with Toyota's VVT-i system which allowed the timing of the intake camshafts to be modified according to the engine's rotation speed and load.

Tim Farr, in a move that raised eyebrows, raced only the Pro Production class. On the SW20's last production year in 1999, the car was updated with a few significant changes. Many Pro racers raced both classes, but the premier class was still the Pro class. In 1996, the front and side signals were changed to use a clear lens but no other modifications were made. The traditional Pro class still allowed two-strokes and hybrids. The side stripes and skirts were also color coded. That same year, the ATVA instituted a Pro Production class at the motocross nationals in order to showcase "stock" ATVs. The original three-piece rear spoiler was replaced with the lighter one-piece spoiler which attached only to the trunklid.

In 2003 Suzuki released the LT-Z400 that featured a liquid-cooled four-stroke powerplant. New round taillights and a color-coded center panel replaced the old square-shaped lights and the rear grille. The Cannondale story was a short one as the company declared bankruptcy shortly after 2002. Having been an option earlier, a limited-slip differential was introduced as standard on all turbocharged models. In 2001, Cannondale entered the ATV market and even fielded an ATV racing team in partnership with Nac's Racing the following year. The normally aspirated 3S-GE received fewer changes but still improved its maximum power to 172 hp (128.3 kW). While it wasn't as powerful as the hybrids racing on the tracks, it was a positive step. For 3S-GTE the use a MAP-sensor, the removal T-VIS in favor of smaller intake ports and the new CT20B turbocharger increased the maximum power to 240 hp (179 kW).

The manufacturers started paying closer attention to the sport ATV market, and in 1999 Honda released the four-stroke TRX400EX. The next big change occurred in 1994, when SW20 received all-new engines for each model and some considerable changes to its exterior. Soon hybrid machines were all over the tracks. Some shifting problems which plagued the first revisions were remedied with stronger synchronization rings. The era of the four-stroke hybrid race ATV was born when Harold Goodman piloted a custom-built YZ400F to a national Four-Stroke Pro-Am championship. Along with the suspension changes, the SW20 also got new 15" wheels to fit the larger brakes that were also introduced. In the late 90s, rules were changed to allow racers to use dirt bike engines in ATV frames. To respond to the feedback they had received, Toyota changed the 1993 model to include wider rear tires and changed the rear suspension, mainly the vehicle's height, shock absorbing properties and a larger rear crossmember, so that the car would be more prone to understeer, thus making it more difficult to push the car into "snap oversteer".

However, in order to be competitive on the motocross track, it was necessary to spend upwards of $20,000 on the race ATV. Some magazines made overstatements where they claimed that the SW20 was downright dangerous to drive. Suspension companies like PEP and Custom Axis, combined with long-travel A-arms and rear suspension links smoothed out rough tracks and harsh landings. This trait was not considered very desirable among the press, because the MR2, unlike expensive supercars, was priced so that even "average people" were able to buy one. Suspension upgrades made it possible for ATVs to hit jumps never thought possible. This made the SW20's cornering abilities quite excellent, but it was much too easy for an inexperienced driver to make a mistake, leading to sudden oversteer (also called "snap oversteer") which can result in a spin unless the driver reacts both quickly and correctly. Companies like Curtis Sparks Racing Engines, Baldwin Motorsports and Hinson Racing made it so the only stock component of the 250R engine were the left and right engine cases. Toyota's goal was to make the car's suspension geometry work the same way that true supercars do.

Again, the aftermarket helped racers get all they could out of the dated engine. The SW20's entry to the market was not quite as smooth as the AW11's. The engine that kept racing alive was the Honda TRX250R engine that was manufactured from 1986 to 1989. The Japanese MR2 GT model was able to accelerate from 0-100 km/h in a stunning 5.9 to 6.2 s. Racers would build expensive, custom ATVs with parts from major aftermarket manufacturers like Laeger's, Walsh Race Craft and Lonestar Racing. The most powerful engine was the turbocharged 3S-GTE, which was again only available in Japan at 220 hp (164 kW) (as the MR2 GT) and the USA at 200 hp (149 kW) (as the MR2 Turbo) so Europeans had to settle with the naturally-aspirated 156 hp (116 kW) 3S-GE engine. Throughout the late 1980s and all during the 1990s, aftermarket companies kept the sport alive, but barely. All engines were 2000 cc I4 engines with DOHC and 16 valves, excluding the naturally-aspirated US model which used the 2200 cc 5S-FE engine.

ATV motocross floundered after Honda, Kawasaki, Suzuki and Yamaha dropped ATV-racing support in the mid 1980s due to the bad publicity of the vehicles. When the SW20 went on sale in spring 1990, it was offered with four different engine choices depending on the market area. Before we can talk about the current state of ATV motocross, we must understand the past. Since the resemblance between the Ferrari 348tb and the Ferrari F355 and the new MR2 was quite striking, the SW20 is sometimes referred to as a "poor man's Ferrari". This was a direct result of the major ATV manufacturers getting involved in the sport. While the AW11 was a pure sports car, made in the spirit of Lotuses, the SW20, being quite larger, could be classed as a GT-car. Starting in the year 2002, ATV motocross started to see a dramatic increase in participation across the United States. The new MR2, designated SW20 (in America the chassis codes were SW20 for the turbocharged model and SW21 for the naturally-aspirated model), was longer, wider and heavier than its predecessor and had smoother bodylines.

Interview with Brad Lackey, World Motocross Champion and one of the test's participants appeared in Racer X Illustrated in 2004 and is recounted here). The MR2 went through a complete redesigned in 1989, when the new Mk II body was produced. (original article appeared in DirtBike magazine in 1980. http://www.padandwheels.com/mr2/index.html. The cardiac stress and strength test results compiled there revealed that the motocross subjects had as high of a fitness level as than any other discipline tested. http://shell.deru.com/~sgn1/AW11/Mkifaq.htm. Athletes from track, American football and soccer were tested, among others. http://shell.deru.com/~sgn1/AW11/4age.htm.

The National Sport Health Institute in Englewood, California tested several professional motocross racers in the early 1980s as part of a comparative study of the cardio-vascular fitness of athletes from various disciplines. http://www.benreedjohnson.com. [citation needed]. http://www.mr2oc.com. At least not if a rider expects to win. For more information about the Mark I visit these websites:. And there are no pauses, breaks or pit stops. The MR2 was on Car and Driver magazine's Ten Best list for 1986 and 1987.

That represents half of an hour in which the faster the rider goes, the more violently and frequently he or she is punished. In 2004, Sports Car International named the MR2 number eight on the list of Top Sports Cars of the 1980s. Finally, a typical professional moto (heat race) lasts at least thirty minutes. The MR2 was Motor Trend's Import Car of the Year for 1985. The G forces produced test the absolute limits of a rider's strength and endurance. The Australian Wheels magazine chose the 1988 AW11 as its favourite sports car. A rider's arms and legs are in constant motion during a race, fighting for control of the motorcycle and absorbing the energy produced by high-speed landings from heights that often exceed twenty feet or from two-foot high stutter bumps (called whoops) that jackhammer the motorcycle and the rider. American car magazines Road & Track and Car and Driver both chose the AW11 on their lists of ten best cars which included some tough competition, such as the Ferrari Testarossa.

The rider is astride a machine weighing at least two hundred pounds and, at the most elite professional level, has an engine that produces at least fifty horsepower. The press received the AW11 with open arms and praised its innovation, great feeling, and responsive engine. He or she must maintain ultra-precise control of a machine traversing terrain that most people would have difficulty walking across while maintaining as high of a rate of speed as possible. Unfortunately, this model was never sold in European markets, although some cars were privately imported. Observing in detail a rider's actions while at speed on the track reveals why. In addition to the new engine, the MR2 SC was also equipped with stiffer stabilizer bars and reinforcements in the bodyshell to improve rigidity. In truth, motocross racing has been found to be one of the most physically demanding sports in existence. The engine produced a maximum power of 145 hp (108 kW) and accelerated the small car from 0 to 100 km/h (0 to 60 mph) in 6.7 to 7.0s.

Those unfamiliar with the sport often assume that the rider is doing nothing more strenuous than steering a motorized vehicle around a field, no more demanding than driving the family car around the block. Based on the same block and head, the 4A-GZE was equipped with a roots-type supercharger and therefore the compression ratio, valve timing and ports were modified. One of the least understood aspects of motocross racing by non-participants is the extreme level of physical fitness required of competitors. In 1988, Toyota brought a new choice for an engine for people longing for more power. Classes for children as young as 4 years old exist for competition on 50cc machines. Some further changes were made to the exterior the following year, but more notable were the addition of larger brakes and a heavier C52 transmission which replaced the older C50. Motocross can be an entry sport for motorsports in general. Other new options included a leather interior and a four-speed automatic transmission.

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). The exterior was modified by color-coding the bumpers and side stripes, adding small side skirts and a translucent spoiler to the rear of the roof. 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. The most important addition was probably having the option of a removable targa top, not available in the US. Usually a race consists of two or three motos with the scores combined to determine the overall result. For the 1986 model year, the AW11 went through several changes which affected both its looks and performance. This competition is called a moto. There was also a JDM model AW10 which used the more economical 1500 cc 3A-U engine, but it didn't gain too much popularity.

The object of the contest is to complete either a defined number of laps (usually three to seven for amateurs, more for professionals) or fixed time period (anything up to 40 minutes) first. The engine had already been introduced earlier on the sportier Toyota AE86 Sprinter Trueno, gathering a lot of positive publicity.
See also the List of motorcycle manufacturers. US-spec engines were rated at 112 hp (84 kW), Euro-spec at 124 hp (93 kW). Previous. The engine was also equipped with a Bosch L-Jetronic type multi-point fuel injection and a variable intake geometry (T-VIS), giving the engine a maximum power output of 128 hp (95 kW). The above five are the major five manufactures in most markets, the manufactures below command little market share (currently - 2005). As a powerplant, Toyota chose to use the 4A-GE 1600 cc I4 engine with two overhead camshafts which allowed the use of 16 valves for a better gas flow through the combustion chamber.

Current. Toyota's cooperation with Lotus during the prototype phase can be seen in the AW11, and it owes much to Lotus's legendary sports cars of the 1960s and 1970s. Incomplete list. Its behavior mimics that of highly expensive supercars and is easy to control and nimble in its movements. See also Motorcycle - especially the "Construction", "Dirt bike/Trail bike" and "Farm bike" sections. Thanks to these features, the AW11 is considered by many to be very enjoyable to drive. Thus, the former 125cc Supercross series is now referred to as AMA Supercross Pro Lites; the 250cc Motocross series is now AMA Motocross Pro; etc. The most important features of the AW11 were its light body, superior handling and relatively powerful, small-displacement engine.

Due to the increase in popularity and to non-matching displacements of four-stroke and two-stroke motorcycles in the same classes, in the year 2005 the AMA changed the class names from 250cc to Pro, and from 125cc to Pro Lite. The two-seat MR2 was definitely not practical as a family car, but the design criteria were different from that of most previous cars. However, the popularity of four-stroke motocross bikes has been steadily increasing. The small and light MR2, designated AW11, was perhaps something no one had expected from any of the Japanese car manufacturers, known for their economical and practical cars. They are very competitive in these classes but need twice the displacement to rival a two-stroke. The car, scheduled to be launched in spring 1984 in the Japanese market under the name MR2 (initially standing for "Midship Runabout, 2-seater" but later claimed to be "Mid-engine, Rear-wheel drive, 2-seater") was to become the first mass-produced mid-engined car to come from a Japanese manufacturer. Currently, 250cc four strokes compete in the 125cc class and 450cc four strokes are used in the 250cc class. Toyota made its SV-3 concept car public in the autumn of 1983 at the Tokyo Motor Show, gathering a huge amount of publicity both from the press and the audience.

Four stroke motocrossers do not compete on a truly level playing field. A significant amount of testing was performed on actual race circuits such as Willow Springs, where former Formula One driver Dan Gurney tested the car. Engine sizes ranges from 50cc right up to 550cc, although bikes with sidecars can have up 1000cc engines. From its base design, the car began evolving into an actual sports car, and further prototypes were tested intensely both in Japan and in California. Some predict that two-strokes will not be available to buy after 2008, perhaps earlier in states such as California. The result was the first prototype in 1981, dubbed the SA-X. These engines have been developed due to manufacturer's pressure and environmental concerns regarding the increased emissions of two-strokes. It was finally decided to place the engine transversely in the middle of the car.

Although the four-strokes weigh more, they have much more power to back up the weight. The actual designwork began in 1979 when Akio Yoshida from Toyota's testing department started to evaluate different alternatives for engine placement and drive method. The highly tuned machines of the professionals are called "factory bikes." The latest trend in motocross motorcycles is towards four-stroke engines. Initially, the purpose of the project was not a sports car. 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 MR2's life began in 1976 when Toyota launched a design project with the goal of producing a car which would be both enjoyable to drive, yet still provide decent fuel economy. Unusual for racing machines, motocross bikes can be purchased in a ready-to-race condition at moderate prices from major motorcycle manufacturers. .

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. The MR2 was eventually designed by Toyota with Lotus engineer Roger Becker involved on its suspension and handling. When the rear wheel is decelerated while the bike is in mid-air, angular momentum is transferred from the wheel to the entire bike. the X100) project was scrapped and Lotus was later bought out by GM. A common technique to change the attitude of the bike in air involves the use of the rear brake. Actually the Lotus M90 (a.k.a. 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. It is a common misconception that the MR2 was Lotus designed, but assembled and distributed by Toyota.

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 lose control of the bike. Thus, the car was sold there only as the MR. Lowering the rider's center of gravity (sitting) greatly increases the ability to go through a turn at higher speeds. When said in French, the name MR2 [ɛm ɛʀ ˈdø] sounds like merde [ˈmɛʀd] (fr: shit). This will affect rotation pitch while jumping and greater traction to the front wheel when necessary on the ground. The latest version was called the Toyota MR-S in Japan, the Toyota MR2 Spyder in the United States, and the Toyota MR2 Roadster in Europe. This offers the rider greater protection when he or she hits bumps or lands hard and allows the rider to move and distribute his or her weight over the front or rear of the bike. The Toyota MR2 was a two-seat, mid-engined, rear wheel drive sports car produced by Toyota from 1984 to 2005.

The saddle (seat) is curiously shaped, in a long banana, to extend from rear of the fuel tank to the rear fender. 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. They feature hinged footpegs and levers so that they simply fold rather than bend or snap when the machine is inevitably dropped. 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 high top speed.

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). . There are two motos in a race and the riders place in those heats are averaged together to get their overall finish. Races are ran in sessions called motos.

The first three riders that finish first are declared the podium riders because of the first though third positions in the race. In each race there is a set number of laps and the first rider to complete the set number of laps is the victor. Other formats may be determined by laps. This format is known as 30 minutes plus 2 laps.

A one-lap-to-go signal is given at the start of the final lap, and the race is completed at the end of that lap. A typical Pro race will run for 30 minutes, then once the leader crosses the finish line that lap, he is given a signal indicating there are two laps remaining. Professional races measaured by time. Due to the size of the track, motocross races often include more than 40 racers whereas Supercross races are generally limited to about 25.

It is not unheard of for a Motocross track to be made up entirely of hills and turns with no jumps at all. 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. Motocross is often abbreviated as MX. The name "motocross" is a contraction derived from the words "Motorcycle" and "Cross Country".

Motocross is derived from the French, and was originally called Scrambling when the sport was invented in the UK. Motocross is a form of motorcycle or ATV racing held on enclosed off-road circuits and is the widely considered the world's most popular form of motorcycle racing. Sweden - SVEMO. South Africa - MSA.

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

USA - AMA. CCM (UK). Maico (West Germany). Cannondale (USA).

Husqvarna (Italy, ex Sweden). Vertemati (Italy). VOR (Italy). TM (Italy).

Aprilia (Italy). Husaberg (Sweden). KTM (Austria). Yamaha (Japan).

Suzuki (Japan). Kawasaki (Japan). Honda (Japan).

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