Heavy Hitter 520 Primary Drive Conversion OEM/EBMX Ultra Motors

This kit was designed for riders who want to maximize their bike’s performance. As seen on EBMX FIM E-Xplorer race team bikes ridden by Jack Field & Jess Gardiner. This is the lightest kit on the market, which means less rotational mass, and resistance.

This kit consists of a hybrid sprocket setup, with the rear sprocket being a 7075 T6 Billet with anodized hard coating, and the front sprocket being a machined steel sprocket, heat treated, and counter cut for weight reduction. The chain provided is a Fire Power 520 non-o-ring chain made in Japan for the least amount of rotational resistance.

This primary drive is not a stealth riding kit. This kit is loud but no louder than your typical primary kit. If you’re looking for something functional that has been heavily tested this is your kit!

We do not vulcanize rubber onto our kits because of two simple reasons, Efficiency loss, additional heat & wear. Adding rubber rings on a sprocket will result in a small degree of elasticity which means a loss of power transfer, also reducing the directness of power transfer. The rubber sprocket rings will accelerate chain wear due to additional friction to chain links, and to also include you now have a shelf for debris to sit on for the chain to roll over to pack into the links since there is no place for debris to evacuate to.

Note: Installation and detailed setup infoHERE

Features

• Exclusive dished sprocket design for proper clearance
• 520 non-sealed Japanese Chain included for long-term reliability and reduced rotating mass
• 7075 aluminum design rear sprocket for reduced rotating mass
• Lightweight Counter Cut Steel heat-treated front sprocket for added life and wear properties
• Master link chain for easy chain swaps when it is time for maintenance

Fitment

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

Important Notice:For EBMX & OEM Motor ONLY! Some Aftermarket Motors may have an offset difference, check your chain alignment before riding, most aftermarket motors include shims for proper installation.

This is the known and tested compatibility for this product. Factory variations, dealer options, and aftermarket modifications could affect compatibility in specific cases. Please verify compatibility to the best of your ability before purchasing.