Dr. Pulley 16x13 Sliding Roller Weights 8 Gram

Dr. Pulley 16x13 Sliding Roller Weights for 50cc 4-stroke QMB139 engines. Please select weight from drop-down menu. Traditionally, gear ratio is changed by the up-and-down rolling movement of the roller weights in the ramp of the Movable Drive Pulley (MDF). Now the innovative Dr. Pulley Sliding Roller Weights slide up-and-down the ramp to change the gear ratio. This unique sliding movement (not rolling) provides exclusive advantages to increase CVT performance. With Dr. Pulley, no abnormal wear