The FIM Road Racing World Championship Grand Prix is the premier class of motorcycle road racing, held since 1949. Grand Prix motorcycles are purpose-built racing machines that are neither available for purchase by the general public nor able to be ridden legally on public roads. This contrasts with the various production-based categories of racing, such as the Superbike World Championship and the Isle of Man TT Races that feature modified versions of road-going motorcycles available to the public.