Heavy Hitter 520 Primary Drive Conversion OEM/EBMX Ultra Motors

The Heavy Hitter 520 Primary Drive Conversion is the lightest 520 chain drive kit on the market for the Sur Ron Ultra Bee, designed for riders who want maximum performance with minimum rotational mass. As seen on EBMX FIM E-Xplorer race team bikes ridden by Jack Field and Jess Gardiner.

Fitment:

• Sur Ron Ultra Bee OEM Motor
• Sur Ron Ultra Bee EBMX V1 and V2 XUB-80 Motor

Download Tech Sheet (Assembly & Torque Specs)

NOTE: For EBMX and OEM motors. Some aftermarket motors may have an offset difference, check chain alignment before riding. Most aftermarket motors include shims for proper installation. Installation and detailed setup info here. Ensure all hardware is tightened and Loctite is applied.

No rubber dampers means no efficiency loss, no additional heat buildup, and no debris shelf for chain links to pack into. The exclusive dished sprocket design ensures proper clearance, and the master link chain makes swaps and maintenance simple. Maintains OEM gear ratio and motor alignment. This kit is loud compared to a belt no avoiding that but no louder than any other chain kit on the market.