Confidence-inspiring momentum over obstacles, no gear rattle; Heat-treated forging for strength and toughness, induction-hardened ring gears for maximum life; One piece construction allows less opportunity for failure and provides uniform efficient heat transfer from the clutch disc. No more warped inserts or loose ring gears; Recommended for street and off-road use; Forged, CNC machined and dynamically computer balanced for smoothness and reliability. 601060 is a Pro-Mass flywheel, developed with more inertia for improved climbing and pulling cabilities. Mass distribution techniques give in an optimized inertia increase with a minimized weight penalty. ACT flywheels are serviceable and can be resurfaced with no need to purchase additional parts.