1952 Grand Prix motorcycle racing season
The 1952 Grand Prix motorcycle racing season was the fourth F.I.M. Road Racing World Championship Grand Prix season. The season consisted of eight Grand Prix races in five classes: 500cc, 350cc, 250cc, 125cc and Sidecars 500cc. It began on 18 May, with Swiss Grand Prix and ended with Spanish Grand Prix on 5 October.
Umberto Masetti won his second and final 500cc World Championship title in 1952.
Geoff Duke (pictured in 1951) successfully defended his 350cc World Championship title.
Enrico Lorenzetti won his only world championship in the 250cc class.
1951 Grand Prix motorcycle racing season
The 1951 Grand Prix motorcycle racing season was the third F.I.M. Road Racing World Championship Grand Prix season. The season consisted of eight Grand Prix races in five classes: 500cc, 350cc, 250cc, 125cc and Sidecars 500cc. It began on 8 April, with Spanish Grand Prix and ended with Nations Grand Prix on 9 September. As of 2022, this is the most recent season the premier class was won by a non-Japanese or non-Italian constructor.
Geoff Duke, the 1951 350cc and 500cc World Champion.