Historic Moto Gran Prix Classes

Period 1
1948 – 1968 and like design. Generally foot shift, air-cooled, wire wheels, twin shock.

• Heavyweight 501 cc up (Rayborn class)
• Lightweight 500 down (Carruthers class)

Period 2
1969 – 1982 and like design. Generally air-cooled fours in heavyweight, with two-stroke twins in lightweight.

• Heavyweight 601cc up for four strokes, 401cc up for 2 strokes (Roberts class)
• Lightweight 600 down for four strokes, 400cc down for 2 strokes (Nixon class)

Period 3
1983 – 1991 and like design. Water cooling on some 4 stroke heavyweights and multiple cylinder lightweights.

• Heavyweight: 601cc up. (Lawson class)
• Lightweight 600cc down (Spencer class)

Period 4
1992 – 2005 and like design. Water cooled heavyweights and water cooled multiple cylinder lightweights

• Heavyweight 601 cc up (Edwards class)
• Lightweight 600cc down (Oliver class)