Yep Jon they are 108mm spacing which is why the 100mm spaced Brembo Radials being sold by Cissbury aren't going to fit.
I am told GSXR and R1 ones will fit but I may have to get out and measure some up. I'll probably pop up to see Dallas tomorrow to check out the spacing on his ZX10R Calipers.
May also have to pop into the odd bike shop with my verniers to check out some others
on this web site they list the 100mm caliper for use on Ducati and Aprilia only
http://www.hardracing.com/Brembo/BremboMC.htm Lots of 108mm calipers around so maybe this is what the jap bikes use and according to this web site they do indeed
http://www.carpimoto.it/product/Lang.../Prod_8876.htm http://www.motorcycle-parts-and-acce... ction=&page=1 http://www.spiralspinner.com/English...n/Caliper.html