Motorcycle racing

   Categories
The FIM classifies motorcycle racing in the following four main categories.[1] Each category has several sub categories.
    Road racing
 Road racing is the racing of motorcycles on tarmac. Races can take place either on purpose-built racing circuits or on closed public roads.

   Motorcycle Grand Prix
Grand Prix motorcycle racing refers to the premier category of motorcycle road racing. It is divided into three distinct classes: 125 cc, 250 cc and 800 cc MotoGP. Grand prix motorcycles are prototype machines not based on any production motorcycle. Dorna Sports, MotoGP's parent company, has announced that the 250 cc class will be replaced with a 600 cc class as early as 2009.

  Superbike racing
Superbike racing is a category of motorcycle road racing that employs modified production motorcycles. Superbike racing motorcycles must have four stroke engines of between 800cc and 1200cc for twins, and between 750cc and 1000cc for four cylinder machines. The motorcycles must maintain the same profile as their roadgoing counterparts. The overall appearance, seen from the front, rear and sides, must correspond to that of the bike homologated for use on public roads.

  Supersport racing
Supersport racing is another category of motorcycle road racing that employs modified production motorcycles. To be eligible for Supersport racing, a motorcycle must have a four-stroke engine of between 400 and 600cc for four-cylinder machines, and between 600 and 750 cc for twins, and must satisfy the FIM homologation requirements. Supersport regulations are much tighter than Superbikes. Supersport machines must remain largely as standard, while engine tuning is possible but tightly regulated