when talking about small or large end, i'm referring to the fork ends that the axel goes through.the small spacer end will be .807'' thick ,the larger end will be .625'' thick. being that the fork tube axel holes are larger than the R1,you will need to increase just the outboard o.d. to 1.500'' for both wheel spacers. this is the portion of the spacer that rest up against the forks (use the stock R1 spacer as a comparison). the R1 axel is a smaller diameter than the busa axel so you will need to shim the R1 axel to fit the busa forks by way of machined (out of aluminum)sleeves.the dims for the sleeves are:large end o.d. of 1.258'' -i.d. of 1.104''-length of 1.595'' .you will have a wall thickness of .077''. small end sleeve o.d. of .981'' i.d. of .868'' wall thickness of .0565'' length of 1.595'' . .002'' will be your axel clearance to sleeve.next is to shortened the R1 axel.machine .170'' off the small end & .075'' off the big end.R1 axel should have a after machined length of 9.470''.axel bolt will need a end washer size i.d 9/16 o.d. 1-9/32'' or1-5/16''.front rotors need to be spaced out .240'' to line up with calipers.order from grainger-part#6te19 alum spacers (10 come in a pack.sized.250''.you can hand sand them down to .240'' or run them as is..010'' off per side is o.k.). graiger part # 6eu30 8mm shouldered bolts,order 2 packs.these are for rotor bolts.