A lot of guys want to use the wider wheels from the Crotch Rockets or... Sport Bikes. One problem with doing that is that the the fully assembled wheel is too wide at the hub. Without the cush drive (final driven flange), it would work just fine. However, without it, you have no sprocket mount.

The way I solve this problem is to eliminate that cush drive and the rubber dampers on the inside of the hub. Most Jap manufactured bikes use these to help absorb the shock of the shifting and downshifting on the drive line. They also help to absorb any vibration that occurs. I don't think they are all that necessary. Many brands are manufactured successfully without them..

First of all, I cut a plate the size of the opening out of 1" aluminum stock. I usually use 1" to make sure there's enough material to adjust it in or out as needed to line the sprocket up with the front one. However, I'd recommend you make a trial fit of the wheel with out the cus drive  to see how you have to offset the sprocket... Just to be safe. Then I have the plate machined to fit a 750 rear sprocket to it as well as the bearings in the hub. Next, remove the left bearing from the hub.. then machine and fit the plate to exactly where it suits your needs the best, and the sprockets line up. Now weld the plate in precisely the spot you need it to be. Make a spacer to separate the two hub bearings and insert the bearing in your plate and then the sprocket. You should be ready to go..