A snowmobile’s secondary drive system, which includes: the chaincase, sprockets, and chain, is an intermediate gear reduction drive system. In addition to transferring power from the CVT to the track drive axle, the secondary drive system also provides the necessary gear reduction between the CVT and the track. Without gear reduction here, once the CVT fully up-shifts, the track would spin as fast as the engine RPM. This one to one ratio would be far too fast for the track and suspension components.
