High Quality Content by WIKIPEDIA articles! The 1971 Grand Prix motorcycle racing season was the 23rd F.I.M. Road Racing World Championship Grand Prix season. The season consisted of twelve Grand Prix races in six classes: 500cc, 350cc, 250cc, 125cc, 50cc and Sidecars 500cc. It began on May 9, with Austrian Grand Prix and ended with Spanish Grand Prix on September 26.