S&S Cycle 635 H.O. Gear Drive Camshaft Kit for 2006-2016 Harley-Davidson Big Twins

S&S Cycle 635 H.O. Gear Drive Camshaft Kit for 2006-2016 Harley-Davidson Big Twins

The S&S 635 H.O. Gear Drive Camshaft Kit eliminates timing chain variability and delivers high-lift performance specifically engineered for modified Big Twin engines. Riders experience a strong, focused power band through the mid-to-upper RPM range, with the added precision of gear drive cam timing that enthusiast builders demand.

Key Features

• Gear drive design eliminates timing chain lash for accurate valve timing in performance builds
• Reverses rear cam rotation to provide additional lobe clearance for high-lift profiles
• High-lift cam designed for modified engines with 106ci or larger displacement
• Best power from 3000-6000 rpm
• Kit includes camshafts, inner gear, outer gear drives, bearings, gaskets, and instructions
• Made in the USA

Technical Specifications

• Drive Type: Gear
• Engine Displacement: 106ci and larger
• Compression Compatibility: 10.0:1 to 11.0:1
• Power Range: 3000-6000 rpm
• Kit Includes: Camshafts, inner gear, outer gear drives, inner and outer bearings, gaskets, and instructions

Fitment Notes

• Fits 2006 Harley-Davidson Dyna and 2007-2016 Big Twin models
• Not a bolt-in installation – requires adjustable pushrod and cover kit
• Material must be removed from the inner surface of the stock gear cover during installation
• A hydraulic press and professional-level tools are required
• Cam bearings and gaskets must be replaced at installation
• Gear drives may produce additional valve train noise compared to chain drive
• Works with stock unported heads; CNC ported heads are recommended for maximum results
• Review the Fitment tab for complete year and model breakdown