Just fitted some CBR 600 F3 wheels to my 1998 XR 600 R. I've kept the cush drive by making an aluminium ring to fit a 47mm X 17mm X 14mm bearing, I forgot the bearing number but it's the same size that is used for the brake disc side and front wheel. The original bearing is 56x17x19 and has a spacer built into it. I removed the studs from the cush drive and made some bolts. The thread is 12mm by 1,25 pitch. The standard M12 bolts have a 1.75 pitch. I faced of the head of the bolts so that it doesn't touch the lip that is on the inside of the swingarm. I also ground the lip down to give a bit more clearance. I had the brake disc side of the rear wheel machined 8mm and the cush drive side 30mm in the milling machine at work. I put a 1 1/2mm spacer on the rear brake disc side and made a 6mm spacer out of stainless steel on my lathe for the other side. That's the rear done Bike as I bought it: With the new wheels on it: I then added the shorter supermoto front mudguard: The rear tyre is a michelin pilot power 150/60/17 that is fitted to the F3 5" rear wheel and doesn't touch the chain. The front tyre is the original michelin macadam that came with the wheel and both discs. I'm going to get a pilot power for the front but just want to get it going now!! I have shortened the chain by a couple of links but have yet to make a support for the front brake caliper. I'm still deciding what to do for the front. I have a Talon brake caliper bracket for a 320mm disc but the discs of the CBR are 296mm. I can make a bracket at work or I can drill and tap an 8mm hole in the talon bracket that will move the caliper in. I'm looking forward to getting it done and take some photo's of it outside. Got a few more things to add, waiting for my CR forks, got a 200w stator and I'm going to get new side panels and cr rear fender and LED tail light. I'll write more details when I have the time and I have some more photos of the cush drive on my other PC.