Replacement Flywheel Assemblys / '99-'17 Twin Cams

S&S Replacement Flywheel Assemblies are three piece Twin Cam flywheels with a larger 1.671" crankpin, built to drop into stock crankcases with no modification.

The flywheel assembly is the part of a Twin Cam that everything else depends on, and the stock crankpin is where high output motors tend to find their limit. S&S went to a 1.671" crankpin and a three piece design, which is the fix for a bottom end being asked to handle more than the factory planned for. Nothing about fitting one requires machining.

Why Riders Replace a Twin Cam Flywheel

A larger crankpin spreads load over more area, which is what keeps the assembly together under sustained high output and what makes the motor feel smoother at the same time. The three piece construction allows service in a way a pressed assembly does not. These are engineered to fit directly into stock crankcases with absolutely no modification, and they work with the Timken bearing conversion, sold separately, for builds where bearing capacity is also a concern. Made in the USA.

Flywheel Assembly Specifications

• S&S three piece flywheel design
• Larger 1.671" crankpin
• Fits stock crankcases with no modification required
• Compatible with Timken bearing conversion, sold separately
• Stroke options: 4" for 88", 95" and 100"; 4 3/8" for 96", 103", 106" big bore, 110" and 117"; 4 3/8" for 96", 103" and 110" CVO; 4 5/8" for 124"; plus S&S V-Series
• Made in the USA

Selecting the Right Flywheel Assembly

This product spans 19 variants across stroke and engine application, and several options turn on details like whether your motor has a sprocket shaft bearing race, and whether it is an A or B style Twin Cam. ⚠️ VERIFY your engine year, style and current stroke before ordering, and confirm which piston set the assembly needs to work with.