An upgear kit is usually a great add on to a kitted motor. It provides a high speed in each gear and lowers the RPM speed to provide a safer operating range with less heat. This is also referred to as the 8% upgear kit. This kit is for models that use the Cosa styled of clutches or for bikes that are being rebuilt and are having Cosa clutches installed. it is highly recommended, when installing the kit, is to install a short fourth as well.
