1975 ROKON COBRA 340MX:
SNOWMOBILE-POWERED MOTOCROSS BIKE
BY TOM WHITE
The Rokon 340MX was probably the most unique motorcycle to ever compete. Powered by a 335cc Sachs two-stroke engine (started with a pull-cord),
the Rokon utilized a Salisbury torque converter for a truly
automatic transmission. Rated at 37 horsepower, the
torque converter allowed the engine to run between 6000
and 6700 rpm most of the time.
There were issues with the Rokon 340MX: (1) The
torque converter didn’t provide any engine braking.
Rokon’s cure was to mount touchy disc brakes (eight
years before any of the other manufacturers). ( 2) The
transmission belt was vented to the outside for cooling,
so it was easily contaminated by water that could cause
slipping. ( 3) Riding on loose surfaces was sometimes