I had to mount the rotors concave in (backwards) on my zx-9 forks due to the width of the mean streak front wheel. To make that work, I used longer bolts with machined washers on the calipers to line them up. I have never really liked this setup, and although I can't point to any problems, it just seems like there's a better answer. Well yesterday I had to go to motorcycle safety standdown training, and I was talking to a friend of mine who has an 05 Busa. It has 320mm rotors, but they are flat. This would get rid of my washers or the need for a spacer, and probably give more rigidity to the caliper mounting too. They look like they are the same bolt circle and center hole diameter as our kawi rotors, but i can't find any data. Could someone point me in the right direction?