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