hey guys i was just out mocking mine up and well first things first its almost a direct swap allballs racing makes a bearing swap for this but there are a few other issuse to be sorted. you can use all of the 650 wheel but you will have to have a ne axle made. this is the route im going i dont have measurements yet. it looks like under the lower bearing you will need a spacer to shorten the stem a little bit, and you will have to shave the upper tripple clamp some for the top nut to seat properly. im going to use the 650 rotor and make a new press in sleave that will accept a 17mm axle and use spacers to fit the gsxr nissin caliper. the forks i have the axle threads in to the left leg in going to hone the threads out and use a spcaer to but up against the speedo drive and the fork leg and have the axle nutted on the out side of the fork leg........but this being said the suzuki katana,the bandit and the 80s gsxr forkss are all the same as the 92 gsxr forks i have but with a 17mm axle so this swap should be simple with a bearing swap and some wheel and caliper spacers but to use the 650 rotor you will need a new sleave made i should have pics to come soon ordering the bearings tomorrow and waiting for a reply to see if they make a 20mm wheel bearing so maybe i wont have to make a new axle!
