S&S Cycle 640GE Easy Start Camshafts - Harley Twin Cam Dyna
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.
The S&S Cycle Big Twin Dyna Easy Start 640GE camshaft is engineered for 1999-2006 Harley-Davidson Dyna models, delivering improved low-end torque and throttle response. This gear drive compatible design ensures a direct installation for riders seeking a noticeable performance boost. It also maintains reliable cold-start performance, a crucial benefit for daily riders.
Why riders pick this
- 640GE Easy Start cam profile
- Gear drive compatible design
- Improved low-end torque delivery
- Enhanced throttle response
- Reliable cold-start performance
- Designed for 1999-2006 Harley Twin Cam Dyna
Unlock the true potential of your 1999-2006 Harley-Davidson Dyna with the S&S Cycle 640GE Easy Start camshaft. This performance cam is specifically designed to enhance the riding experience by providing a significant increase in low-end torque and a sharper throttle response. Whether you're navigating city streets or hitting the open road, you'll feel the difference in how your Twin Cam engine pulls from a stop and through the gears. Plus, the Easy Start feature means reliable ignition every time.
Optimized Performance for Your Twin Cam Dyna
- Features the Big Twin Dyna Easy Start 640GE cam profile
- Engineered for direct gear drive compatibility
- Delivers improved low-end torque for quicker acceleration
- Enhances throttle response for a more engaging ride
- Maintains reliable cold-start performance, a key rider benefit
Installation and Tuning Considerations
The S&S Cycle 640GE camshaft is designed for a direct fit into 1999-2006 Harley-Davidson Dyna models equipped with stock gear drive cam systems. This makes installation straightforward for experienced mechanics or DIY enthusiasts. As with any performance camshaft upgrade, a proper dyno tune is highly recommended to optimize fuel mapping and ignition timing, ensuring your engine runs efficiently and safely while maximizing the gains from the 640GE profile.
Specifications
- Brand: S&S Cycle
- Manufacturer Part #: 106-4839
- Weight: 1 lb
- Category: Engine Components / Camshafts
Common questions
Will this S&S Cycle 640GE camshaft fit my 2007 or newer Dyna model?
No, this 640GE camshaft is specifically designed for 1999-2006 Harley-Davidson Dyna models. 2007 and newer Dyna models require different cam profiles due to changes in engine design.
Is this camshaft compatible with gear drive cam systems?
Yes, the S&S Cycle 640GE profile is engineered specifically for gear drive compatibility, allowing for direct installation in appropriate Twin Cam Dyna models.
Will I need to get my motorcycle tuned after installing this camshaft?
Yes, installing a performance camshaft like the 640GE will change your engine's operating characteristics. A professional dyno tune is strongly recommended to optimize fuel delivery and timing for the best performance and engine longevity.
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 | Camshafts |
| SKU | T14-663421 |
| WEIGHT | 1.0 lb |