The almost unlimited growth of rear tire width has driven the Custom Bike Builders to the outer limits of offsetting primary drives in existing frames. Our 55mm primary offset kit is really the limit of what is possible, extending the main shaft further will put too much torsion stress on the shaft, the 330 tire really needs a different approach. We strongly feel that instead of offsetting the primary to the extreme, it is better to leave the primary in the original position and move the final drive over to the right side. Zodiac developed a swing arm and transmission conversion kit that allows the use of a 300 or 330 wide rear tire in a stock Evolution or Twin Cam Softail frame. We offer two very cost-effective solutions, one with a RSD conversion kit, that re-uses as many stock parts as possible, and one with a RSD builder's kit. The RSD transmission conversion kit only includes the parts that are needed to convert your stock transmission into a RSD transmission. It includes parts such as: main shaft, counter shaft, shift drum, shift forks, etc. It also includes a new Billet trap door that gives room for the main drive gear. To avoid any "not wanted" load on the cast transmission housing, we have designed the trapdoor in such a way it is not only supported by the lower frame tube but also by de swing arm pivot. To make the internals of transmission stronger, the fifth gear countershaft has become an integrated part of the countershaft. We have completed the kit with the required hardware, new seals and gaskets. Some builders may not want to use their old transmission gears, for those we have a complete builders kit available. Builder's kits have the gears and shafts installed on the trap door, and include all internal parts of the transmission. You can use these in your own or new transmission housing. All RSD conversion and builders kits use a special RSD clutch actuator/pulley cover, which is separately available. Clutch actuators are available in hydraulic or cable operated. The cable operated clutch actuator works with stock Big Twin clutch cable, the hydraulic operated clutch actuator requires an 11/16" bore master cylinder. We have OEM style and Custom Style clutch master cylinders available, check out our Handlebar Controls section. Kits for up to 300 series rear tire include RSD transmission conversion or builders kit, TIG welded swing arm, stainless steel swing arm splashguard, and rear wheel axle. Kits for up to 330 series rear tire also include an offset final drive front pulley, extended clutch pushrod and a spacer ring for the clutch actuator/pulley cover. For those that prefer to use a wide wheel with 1" bearing we have bearing sleeves ZPN735416 and ZPN735417 available. A raw steel RSD belt guard is available separately.
Note: Installation in Softail "Deuce" models requires some modification of the frame and swing arm.