Motorcycle a three-speed gearbox and belt transmission. It was so popular with its users that it was nicknamed the "Trusty Triumph." By 1920, Harley-Davidson was the largest manufacturer, with their motorcycles being sold by dealers in 67 countries. In the 1950s, streamlining began to play an increasing part in the development of racing motorcycles and the "dustbin fairing" held out the possibility of radical changes to motorcycle design. NSU and Moto Guzzi were in the vanguard of this development, both producing very radical designs well ahead of their time. NSU produced the most advanced design, but after the deaths of four
Motorcycle racing 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. Endurance racing is a category of motorcycle road racing which is meant to test the durability of equipment and endurance of the riders. Teams of multiple riders attempt to cover a large distance in a single event. Teams are given the ability to change riders during the race. Endurance races can be run either to cover a set distance in laps as quickly as possible, or to