Yamaha Models of Motorcycle & Scooter Sprockets. Our Yamaha drive sprockets offer optimum quality in terms of design, materials and machining. Made to OEM specifications these front and rear sprockets are made from high grade case hardened steel and exceed the OEM quality standards set out by the major manufacturers. Always purchase a high quality case hardened, steel front counter shaft sprocket or drive sprocket for your motorbike as these are high wear items. If you require non-standard sprockets, extra or fewer teeth than standard, please use the contact page and request the number of teeth required if not listed here but be sure to include you bike manufacturer, model and year.