To solve the problems of Vbelt’s slippage during starting phase and the difficulty of the ratio change of snowmobile's rubber Vbelt clutch system, the main reason of the Vbelt’s slippage is found based on the axial force analysis of the primary clutch. Then the speed characteristic of the continuously variable transmission with dual quadrant flyweight is analyzed. The results show that the dual quadrant flyweight not only solves the problem of the Vbelt’s slippage during starting phase effectively, but also increases the transmission efficiency of the clutch system, and improves the characteristic of ratio change of the snowmobile's rubber Vbelt clutch system.