S&S Cycle 84-99 BT 4-5/8in Stroke Flywheel Assembly

If you're building or rebuilding a high-performance S&S 124" V124 engine for your 1984-99 Harley-Davidson big twin, this flywheel assembly is a critical component. It replaces your original flywheels and is designed to handle the demands of a larger displacement engine, providing a solid foundation for serious power.

This assembly features a three-piece design where the pinion and sprocket shafts are forged directly into the flywheels, minimizing potential failure points. The only joint is where the 1.671" diameter connecting rod crankpin is pressed in. The flywheels themselves are CNC machined from heat-treated, closed die steel forgings, making them significantly stronger than stock steel flywheels. They come fully assembled with heavy-duty S&S 7.667" connecting rods, featuring full-width wrist pin ends, and are dynamically balanced. This meticulous balancing and truing to less than .0005" runout on the bearing surfaces means this assembly is ready for higher RPM operation.

This flywheel assembly is a substantial upgrade for performance-minded builders. Please note that this part is not CARB approved and cannot be shipped to California.