The mobile driven split pulley comes from our racing department's many years of experience, and is manufactured with the best possible special nitrided steels in order to ensure a long life. This component called Torque Driver for its specific function of determining the exact shifting moment, was calculated to give the vehicle the maximum possible acceleration in connection with the specific power of any single engine. The spiral's peculiar shape was studied to fix the RPMs on the point of maximum power. It was expressly created to complete the development of boosted motors withour cylinders, variators and the special Malossi Kevlar Belts, allowing to fully exploit your vehicle's notable torque and power. The new Malossi mobile driven split pulley ensures, on boosted vehicles,extraordinary acceleration and an extremely progressive and fluid torque output to the wheel. The tracks on the Malossi mobile driven split pulley were studied and designed on CAD-CAM systems and machined on CNC machinetools in order to guarantee total interchangeability with the original component and extremely high machining accuracy. This new Malossi product is a concentrate of today's state-of-the-art technology. Compatible with: - Aprilia: SR 50 04-Piag._S - Derbi: GP1 50 LC_S - Gilera: DNA 50 LC_S, Runner SP 50 -05_S, Runner SP 50 06-_S, Stalker 50 AC_S - Piaggio: NRG 50_S, Vespa 97-_S, ZIP SP 01-_S