Monday 20 July 2009

de Motocyclisme

A Road Racing World Championship Grand Prix was first organized by the Fédération Internationale de Motocyclisme (FIM) in 1949. The commercial rights are owned by Dorna Sports. Teams are represented by the International Road Racing Teams Association (IRTA) and manufacturers by the Motorcycle Sport Manufacturers Association (MSMA). Rules and changes to regulations are decided between the four entities, with Dorna casting a tie-breaking vote. In cases of technical modifications, the MSMA can unilaterally enact or veto changes by unanimous vote among its members.[1] These 4 entities compose the Grand Prix Commission.

There have traditionally been several races at each event for various classes of motorcycles, based on engine size, and one class for sidecars. Classes for 50cc, 80cc, 125cc, 250cc, 350cc, and 500cc solo machines have existed over time, and 350cc and 500cc sidecars. Up through the 1950s and most of the 1960s, four-stroke engines dominated all classes. In the 1960s, two-stroke engines began to take root in the smaller classes. By the 1970s, two-strokes completely eclipsed the four-strokes. In 1979, Honda made an attempt to return the four-stroke to the top class with the NR500, but this project failed, and in 1983, even Honda was winning with a two-stroke 500. The 50cc class was replaced by an 80cc class, then the class was dropped entirely in the 1990s, after being dominated primarily by Spanish and Italian makes. The 350cc class vanished in the 1980s. Sidecars were dropped from World Championship events in the 1990s (see superside), reducing the field to 125s, 250s, and 500s.
Yamaha YZR-M1 MotoGP bike

MotoGP, the premier class of GP motorcycle racing, has changed dramatically in recent years. From the mid-1970s until 2002 the top class of GP racing allowed 500cc with a maximum of 4 cylinders, regardless of whether the engine was a two-stroke or four-stroke. Consequently, all machines were two-strokes, due to the greater power output for a given engine capacity. Some two- and three-cylinder two-stroke 500s were seen, but though they had a minimum-weight advantage under the rules, typically attained higher corner speed and could qualify well, they lacked the power of the four-cylinder machines. In 2002, rule changes were introduced to facilitate the phasing out of the two strokes, probably influenced by what was then seen as a lack of relevance: the last mass-produced 500cc 2-stroke model had not been available to the public for some 15 years.[original research?] The rules permitted manufacturers to choose between running two-strokes engines (500cc or less) or four-strokes (990cc or less). Manufacturers were also permitted to employ their choice of engine configuration. Despite the significantly increased costs involved in running the new four-stroke machinery, given their extra 490cc capacity advantage, the four-strokes were soon able to dominate their two-stroke rivals. As a result, by 2003 no two-stroke machines remained in the MotoGP field. The 125cc and 250cc classes still consist exclusively of two-stroke machines. In 2007, the MotoGP class had its maximum engine displacement capacity reduced to 800cc for a minimum of 5 years.

The 2008 racing calendar consisted of 18 rounds in 16 different countries (Spain which hosted 3 rounds, Qatar, Turkey, China, France, Italy, Great Britain, the Netherlands, Germany, Czech Republic, San Marino, Portugal, Japan, Australia and Malaysia). Exclusive to the MotoGP class, there was also a USA round at Mazda Raceway Laguna Seca in Monterey, California for the 800cc class only, as California's strict emissions law bans two-stroke motorcycles. In 2008 a MotoGP event was held at the Indianapolis Motor Speedway for the first time on a newly prepared track, and observers noted that the Speedway had hosted motorcycle racing before cars raced there. All three classes were scheduled to race but severe wind and rain prevented the 250cc class from racing. MotoGP racing at Indianapolis is counterclockwise, starting on the Formula One track, with additional turns directly after the pit area, bypassing the banking turn one of the oval track. Also because of the race being run counterclockwise on what is normally a clockwise track, the run off areas have seen significant modification.

The grid is composed of three columns (four for the 125cc and 250cc classes) and contains approximately 20 riders. Grid positions are decided in descending order of qualifying speed, the fastest on the 'pole' or first position. Races last approximately 45 minutes, each race a sprint from start to finish without pitting for fuel or tires.

In 2005, a flag-to-flag rule for MotoGP was introduced. Previously, if a race started dry and rain fell, riders or officials could red-flag (stop) the race and either restart or resume on 'wet' tires. Now, if rain falls a white flag is shown, indicating that riders can pit to swap the motorcycle on which they started the race for an identical one, as long as the tires are different (that is, intermediates instead of wets, or slicks instead of wets)[1]. Besides different tires, the wet-weather bikes have steel brake rotors and different brake pads instead of the carbon discs and pads used on the 'dry' bikes. This is because the carbon brakes need to be very hot to function properly, and the water cools them too much. Hence the conventional steel brakes. The suspension is also 'softened' up somewhat for the wet weather.

When a rider crashes, track marshals wave a yellow flag, prohibiting passing in that area; one corner back, a stationary yellow flag is shown and passing in this area of the track is prohibited; if a fallen rider cannot be evacuated safely from the track, the race is red-flagged. Motorcycle crashes are usually one of two types: lowsides and the more dangerous highsides, though increased use of traction control has made highsides much less frequent.

According to one estimate, leasing a top-level motorcycle for a rider costs about 3 to 3.5 million dollars for a racing season.[2]

As a result of the 2008-2009 financial crisis, MotoGP is undergoing changes in an effort to cut costs. Among them are reducing Friday practice sessions; banning active suspension, launch control and ceramic composite brakes; extending the lifespan of engines; reducing testing sessions.

Sunday 19 July 2009

rossi won

Grand Prix class

125cc and 250cc classes
125cc KTM Grand Prix motorcycle

125cc machines are restricted to a single cylinder and a minimum weight of 80 kilograms and the 250cc machines to two cylinders and a minimum of 100 kilograms. From 2005 onwards, all riders in the 125cc class could not be older than 28 years or 25 years for new contracted riders participating for the first time and wild-cards.

In 2008 discussions arose surrounding the replacement of the 2-stroke 250cc class with another category. The move to 600cc 4-stroke engines to replace the current 250s has been finalized as of June 2008 and will take effect in 2011 [7] The new class will be called Moto2. Engines will be produced by Honda[8]; tyres by Dunlop and electronics will be limited and supplied only by FIM sanctioned producers with max cost set at 650 EUR; carbon-fibre brakes will be banned and only steel brakes will be allowed. However, there will be no chassis limitations.[9]
[edit] MotoGP class

New specifications for each racing class are formed as the FIM sees fit. At the beginning of the new MotoGP era in 2002, 500cc two-stroke or 990cc four-stroke bikes were specified to race. The enormous power advantage of the larger displacement four-stroke engine over the two-stroke eliminated all two-strokes from competition; the following season no two-stroke bikes were racing. In 2007 the maximum engine capacity was reduced to 800cc without reducing the existing weight restrictions.

MotoGP-class motorcycles are not restricted to any specific engine configuration. However the number of cylinders employed in the engine determines the motorcycle's permitted minimum weight; more cylinders attracting more weight as a form of handicap. This is necessary because, for a given capacity, an engine with more cylinders is capable of producing more power. If comparable bore to stroke ratios are employed, an engine with more cylinders will have a greater piston area and a shorter stroke. The increased piston area permits an increase in the total valve area, allowing more air and fuel to be drawn into the engine, and the shorter stroke permits higher revs at the same piston speed, allowing the engine to pump still more air and fuel with the potential to produce more power but with more fuel consumption too. In 2004 motorcycles were entered with three-, four-and five-cylinder configurations. A six-cylinder engine was proposed by Blata, but did not reach the MotoGP grids. Presently four cylinder engines appear to offer the best compromise between weight, power and fuel consumption as all competitors in the 2009 series use this solution in either 'V' or in-line configuration.

In 2002, the FIM become concerned at the advances in design and engineering that resulted in higher speeds around the race track. For purposes of increasing safety, regulation changes related to weight, amount of available fuel and engine capacity were introduced. The amended rules reduced engine capacity to 800cc from 990cc and restricted the amount of available fuel for race distance from 26 litres in year 2004 to 21 litres in year 2007 and onwards. In addition, the minimum weight of 4 cylinder bike used by all participating teams was increased by 3 kg.

The highest speed for a MotoGP motorcycle is 349.288kph (217.037 mph), set by Dani Pedrosa riding a Repsol Honda RC212V 800cc during Free Practice 1 at the 2009 Italian motorcycle Grand Prix.[10] By way of comparison, the current Formula One speed record of 369.9kmh (229.8 mph) was set by Antônio Pizzonia of the BMW Williams F1 team, at Monza in 2004—however, top speed is only a small portion of the overall capabilities of any track vehicle and thus does not represent the difference between Formula One and MotoGP performance-wise in general. Using lap timings as a guide, MotoGP riders typically lap the Spanish Circuit de Catalunya in 1 minute 43 seconds compared to 1 minute 23 seconds for Formula One. Generally, cars have more grip thanks to more tires with bigger surface contact area which results in greater corner speed. Bikes have better acceleration regarding to better power to weight ratio. Both of these "rules" apply when comparing an F1 car with a MotoGP bike.
[edit] Weights
Minimum Weight - MotoGP Class Number of
cylinders 2002 Minimum 2007 Minimum Difference
2 135 kg (300 lb) 137 kg (300 lb) 2 kg (4.4 lb)
3 135 kg (300 lb) 140.5 kg (310 lb) 5.5 kg (12 lb)
4 145 kg (320 lb) 148 kg (330 lb) 3 kg (6.6 lb)
5 145 kg (320 lb) 155.5 kg (343 lb) 10.5 kg (23 lb)
6 155 kg (340 lb) 163 kg (360 lb) 8 kg (18 lb)

* In 2005, fuel tank capacity was reduced by 2 litres to 24 litres
* In 2006, fuel tank capacity was reduced by a further 2 litres to 22 litres
* From 2007 onwards and for a minimum period of five years, FIM has regulated in MotoGP class that two-stroke bikes will no longer be allowed, and engines will be limited to 800cc four-strokes. The maximum fuel capacity will be 21 litres.