Motorcycle racing is a competition of speed and agility between motorcycle riders. The motorcycles used in motorcycle racing are custom-built road racing machines, which are different from those used for other types of motorcycling. The races involve both solo and team competitions, as well as various classes of motorcycles, including those based on production or concept designs.
The races are divided into different categories, according to the machine type, the region of the world in which it is run and for some events, by the level of experience of the driver. Beyond this, however, there is no rigid distinction between types of motorcycles. Sometimes “production racer” is used as a category in place of Superbike.
The sporting regulations for each category specify restrictions in relation to the motorcycle’s possible sources of power. Restrictions on engine size, displacement capacity, and fuel tank capacity are highly dependent on the particular category, but other components may be restricted or outlawed. This has less influence over the motorcycles’ performance than factors such as wheel diameter, weight (in GPs, some races prohibit bikes with a weight per cubic centimeter of 0.5 kg/cm³), maximum rpm, and individual motorcycle dimensions; but is still an important factor in deciding which motorcycles can be used at the same level of competitiveness.