Manitoba Roadracing Association (MRA) race classes

Canadian Thunder




 Engine Displacement (must be OE in bore and stroke)

a) Two cylinder: 850cc maximum

b) Three cylinder: 675cc maximum

c) Four cylinder: 636cc maximum


 Engine displacement is unlimited, retaining stock bore and stroke.

Canadian Thunder

a) 0-250cc two-stroke water-cooled “racing” engines maximum of two cylinders;

b) 0-450cc two-stroke air-cooled maximum of two cylinders;

c) 0-500cc two-stroke single cylinder;

d) 0-450cc water-cooled production based “street” crankcases unlimited cylinders;

e) 0-650cc four-stroke liquid-cooled two cylinders;

f) Unlimited displacement four-stroke single cylinder;

g) 0-999cc 2 valve per cylinder desmodromic, air-cooled twins;

h) 0-1300cc air-cooled twins with pushrod activated valves (ie. Buells).