S&S 4-3/8" Stroke Flywheel+ Rods+ Balancer Gear HD M8 Models
The flywheels are the heart of any performance engine and S&S Cycle has been perfecting the art for over six decades. Stronger, more durable, and trued to a spec others can only dream of, the new cranks for the Milwaukee-Eight® platform are the best of the best to build your high performance engine around.
FEATURES & BENEFITS
- 4-3/8" Stroke (107 or 124ci)
- Balance Gear installed
- Heat Treated 4140 Material is harder & more than twice as strong as stock
- Stronger assembly eliminates need to weld crankpin
- Capable of higher RPM - More available power!
- S&S High Strength Connecting Rods are designed with Finite Element Analysis to eliminate weak spots and handle more power!
- Full width wristpin connecting rods (requires S&S Performance Pistons)
- Balanced for S&S Performance piston weight (1213g)
- Perfect for Gear Drive Cams
- Consistent balance & precision machining
- Capable of higher RPM – More available power!
Fitment
Softail Breakout FXBR 2018, 2019
Softail Deluxe FLDE 2018, 2019, 2020
Softail Fat Bob FXFB 2018, 2019
Softail Fat Boy FLFB 2018, 2019
Softail Heritage Classic FLHC 2018, 2019, 2020, 2021
Softail Low Rider FXLR 2018, 2019, 2020
Softail Slim FLSL 2018, 2019, 2020, 2021
Softail Sport Glide FLSB 2018, 2019, 2020, 2021
Softail Standard FXST 2020, 2021, 2022, 2023
Softail Street Bob FXBB 2018, 2019, 2020
















