S&S 4" Stroke Flywheel For Harley Twin Cam

• Vast improvement over stock flywheels which shift out of true under heavy load
• Heat-treated 4140 material is 114% stronger than stock, eliminates thrust washer
• Larger 1.671" crankpin, increased cross-sectional area for increased crank-pin clamping force
• Harder material, no thrust washers required, where stock flywheels have thrust washers
• S&S flywheels have steel gripping the crankpin
• No welding required
• Integral mainshafts,consistent balance and precision machining, truer flywheels and less vibration, and eliminates two potential points of weakness
• Reduced mainshaft deflection at high rpm, less vibration, reduced piston and rod side thrusting, prevents oil pump damage, fully compatible with gear drive cams
• Capable of higher rpm which allows more available power
• Includes sprocket bearing race