S&S Cycle Camshafts — 1999-2006 Harley-Davidson Dyna Easy

S&S Cycle Big Twin Dyna Easy Start 640GE camshaft for 1999-2006 Harley-Davidson Dyna models, engineered to deliver improved low-end torque and throttle response while maintaining reliable cold-start performance. Gear drive compatible design for direct installation.

Features

• Big Twin Dyna Easy Start 640GE profile
• Gear drive compatible
• Improved low-end torque delivery
• Enhanced throttle response
• Reliable cold-start performance

Specifications

• Brand: S&S Cycle
• Manufacturer Part #: 106-4839
• Weight: 1 lb
• Category: Engine Components / Camshafts

Fitment

Fits 1999-2006 Harley-Davidson Dyna models with stock gear drive cam systems.

Frequently Asked Questions

Will this fit my 2007+ Dyna?

No — this camshaft is designed for 1999-2006 Dyna models. 2007 and newer require different cam profiles.

Is this compatible with gear drive cam systems?

Yes. This 640GE profile is engineered specifically for gear drive compatibility.

Does this improve performance over stock?

Yes — the 640GE profile delivers improved low-end torque and throttle response compared to stock Dyna cams.

Will I need to tune my bike after installation?

A fuel tune may optimize performance gains. Consult with your tuner or S&S Cycle for specific recommendations based on your setup.

Is cold starting affected?

No — the Easy Start profile maintains reliable cold-start performance despite the torque improvements.