American Prime Manufacturing Inc. Transmission Mainshaft Bearing Support Forget the over-engineered junk real riders know that nothing beats the raw look of a classic open belt drive. This high-strength 356 T6 aluminum support replaces that bulky inner primary, giving your transmission the bulletproof reinforcement it needs to handle the heavy-duty spinning weight of your clutch basket. Stop worrying about your mainshaft and start riding like you mean it. Features: Cast from 356 t6 high strength aluminum Automotive style sealed ball bearing Must use stock mainshaft nut