Motorcyle Racing
Motocycle racing falls under main categories, according to the FIM:
ROAD RACING
Road racing is motorcycle racing on tarmac, and races can take place either on racing circuits built for the purpose of racing, or on closed public roads. A subcategory of road racing is Grand Prix motorcycle racing, which is this sport’s premier echelon.
Another subcategory is superbike racing – which uses modified production motorcycles that have four strong engines between 800 cc and 1200 cc for twin cylinders and between 750 cc and 1000 cc for four cylinder machines.
Supersport racing is another category of motorcycle road racing, which again uses modified production motorcycles. Here, a motorcycle must have a four-stroke engine of between 400 and 600 cc for four-cylinder machines, and between 600 and 750 cc for twin cylinders. Note that supersport regulations are much tighter than what you’d find in superbikes.
Yet another subcategory of motorcycle road racing is endurance racing. Here, teams of multiple riders try to cover a large distance across a single event – and races can be set up to either cover a set distance as quickly as possible, or to cover as much distance over a predetermined amount of time.
MOTOCROSS
Motocross (otherwise known as MX) is just like road racing but off road – meaning its a number of bikes racing in a closed circuit.
Motocross has a plethora of classes based upon machine displacement (ranging from 50cc 2-stroke youth machines up to 250cc 2-stroke and 450cc 4-stroke), age of competitor, ability of competitor, sidecars, quads/ATVs, and machine age (classic for pre 1965/67, Twinshock for bikes with two shock absorbers, etc).
Supercross (or SX) is just indoor motocross, notable for its many jumps.
The love child of road-racing and motocross would be supermoto racing. The motorcycles themselves are primarily motocross types with road-racing tires.
Another category of motorcycle racing would be Endoro, which is a form of off-road that tests riders endurance and typically last a two to three hours. As well, cross-country racing is another category, which are much bigger than enduros. These can take place across several days.