Seriously - although I haven't done it myself I have been told the wheels of the R1100S bolt straight on. I am sure I will be corrected very quickly if this is wrong but we shall see....
actually the R1150 RS use the same set up,they will bolt right on,front and rear,Use the 5" rear.... NoT the 5'5"(to wide)
if you want to go the R11S way, you need to use your GPS for spedo ,or use a pushbike speedo like I do,or spend many hours machining the hub to fit the speedo drive....no fun
Simplest/best way to go: front: 17" rim from RT. Back: rim from 1150RS. Watch for correct speedodrive. I believe the one installed is from the RT. More accurate, too.
Dave U.