S&S Cycle Flywheels 4.5-inch Stroke, Stock Piston Weight - Harley-Davidson
About S&S Cycle
S&S Cycle has built American V-twin performance parts in Viola, Wisconsin since 1958 — flywheels, carburetors, cams, cylinder heads and complete crate engines. When a Harley owner talks about a 124, a 128 or a 131 build, they are usually talking about S&S. Few names carry more weight with engine builders in this space.
Lay the groundwork for a robust and powerful Harley-Davidson engine with S&S Cycle Flywheels, engineered for durability and performance. Forged from heat-treated 4140 material, these flywheels are designed to handle sustained high-RPM power. They are precision-trued and balanced to work seamlessly with stock piston weights, making them a prime choice for serious upgrades.
Why riders pick this
- Heat-treated 4140 material, over 2x stronger than stock
- Tapered wristpin compatible with stock pistons
- Balanced for stock 1060g piston weight
- 4.5-inch stroke for 114 or 128ci builds
- Optimized for gear drive cam conversions
These S&S Cycle flywheels are a critical upgrade for riders looking to fortify their Harley-Davidson engine. Built with finite element analysis, weak spots are eliminated, providing more than twice the strength of stock components. The tapered wristpin design ensures compatibility with stock pistons, making this a versatile foundation for performance builds. With a 4.5-inch stroke, these flywheels are suitable for 114 or 128 cubic inch engine projects and are optimized for gear drive cam conversions, offering a significant boost in reliability and power potential.
Strength and Precision for Your V-Twin
- Heat-treated 4140 material for superior strength
- Finite element analysis design for enhanced durability
- Tapered wristpin compatible with stock Harley pistons
- Balanced for stock 1060g piston weight
- 4.5-inch stroke fits 114 or 128 cubic inch engines
- Optimized for gear drive cam conversions
The Core of a Performance Engine
Installing these S&S Cycle flywheels provides a strong, balanced core for your engine, capable of handling higher RPMs and increased power outputs. Their design is particularly beneficial for those planning a gear drive cam conversion, as it supports the demands of such an upgrade without the need for crankpin welding. Always verify your engine's displacement and cam drive type to ensure perfect compatibility with your specific Harley-Davidson model.
Specifications
- Brand: S&S Cycle
- Manufacturer Part #: 320-0598
- Category: Drivetrain / Flywheels
- Weight: 40 lb
Common questions
Will these flywheels work with my stock pistons?
Yes, the tapered wristpin design of these S&S Cycle flywheels is specifically engineered to be compatible with stock Harley-Davidson pistons.
Are these suitable for gear drive cam conversions?
Absolutely. These flywheels are optimized for gear drive cam conversions, providing the strength and stability needed for such an upgrade.
What stroke length do these flywheels have?
These flywheels feature a 4.5-inch stroke, making them suitable for 114 or 128 cubic inch engine builds.
Ordering from Vtwinbikers
- Brand new, sourced through authorized US distribution — never used, never grey-market.
- Not sure it fits? Use Shop by Bike to filter by your year and model, or email us and we will confirm before you order.
- Harley-Davidson and Indian Motorcycle is all we do, so you are talking to people who ride what you ride.
| BRAND | S&S Cycle |
| TYPE | Flywheels |
| SKU | T14-662048 |
| WEIGHT | 40.0 lb |
