BBR Tuning 2-Stroke Motorized Bicycle Billet Springer Chain Tensioner &ndash; Gas Bike Case Mounted Chain Idler Pulley Upgrade Consistent Chain Tension: The BBR Tuning 2-Stroke Motorized Bicycle Billet Springer Chain Tensioner is designed to keep your chain taunt with zero adjustment. This tensioner features a heavy duty spring and 10 tooth sprocket that supports the chain, keeping your chain adjusted and prevents it from coming out of alignment. Extends Chain Lifespan: Instead of using a roller, the 10 tooth drive sprocket on this tensioner guides the chain rather than rolling against the chain and causing wear from friction. This drastically increases the life of your chain and is less strain on your engine. Easy Installation: Installation is a breeze, just remove your stock drive sprocket case cover. Remove your bucking bar and insert the supplied clutch actuator bearing and reinstall your bucking bar. Next bolt on your new BBR Tuning Spring Chain Tensioner with your stock case cover and your good to go! Universal Fit: Designed to work with most standard 2 stroke 48cc, 60cc, 66cc and 80cc bicycle engines. Package Includes: 1x BBR Tuning Springer Chain Tensioner, 1x Clutch Actuator Bearing