Traditionally, the gear ratio in scooter CVTs is changed by the in-and-out rolling movement of the roller weights With the innovative Dr Description Traditionally, the gear ratio in scooter CVTs is changed by the in-and-out rolling movement of the roller weights. With the innovative Dr. Pulley sliding roller weights, the roller weights “slide” inward and outward in the Movable Drive Pulley (MDF) to change/extend the gear ratio. Dr. Pulley sliding roller weights provide the following advantages over traditional “rolling” roller weights: Eliminate abnormal wear in the high gear position. Enjoy a broader range of gear ratios. Experience outstanding acceleration and re-acceleration properties. Retain explosive low end acceleration and reach higher top speeds. Last longer than traditional roller weights while experiencing excellent CVT variator performance. U.S. patent no. 7276004. Specifications Size: 15×12 Available Weights: 3.5g, 4.0g, 4.5g, 5.0g, 5.5g, 6.0g, 6.5g, 7.0g, 8.0g, 8.5g, 9.0g, 9.5g, 10.0g