Pro Stock Motorcycle Pro Stock Motorcycle Pro Stock Motorcycle, formerly known as Pro Stock Bike, is a motorcycle drag racing class that is the two-wheeled equivalent of Pro Stock. It has been a feature of NHRA drag racing since the 1980s when it was added to the professional class structure and has since spread around the globe. The first points championship season was the 1987 NHRA season. The class has for years been dominated by inline-4 cylinder Suzuki based bikes but in recent years Harley-Davidson based V-twin machines have become more competitive due to favorable rule changes (160 c.i. Harleys vs. 107 c.i
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