I was thinking of getting an 18 incher on the back. What effect will it have on the overall gearing? Anyone know? Will it be the same as fitting the taller 5 gear?
I have seen Moorespeed offer an 18 incher. I should e mail him. I suppose I would have to either rig another speedo or recalibrate. Probably not worth the hassle.
"If you want to run an 18-inch rear wheel (which will cosmetically match the front if you have upgraded the suspension) then the solution is to use the hub from a BMW R80G/S or ST, which uses a conventional rim."
The other option:-
Fit the r100r front rim. This is a 2.50 x 18 MTH 2 instead of the 2.50 X 17 MTH 2 of the GS