1967 Grand Prix motorcycle racing season
The 1967 Grand Prix motorcycle racing season was the 19th F.I.M. Road Racing World Championship Grand Prix season. The season consisted of thirteen Grand Prix races in six classes: 500cc, 350cc, 250cc, 125cc, 50cc and Sidecars 500cc.
Source: Wikipedia — 1967 Grand Prix motorcycle racing season (CC BY-SA 4.0)