As part of my sidecar rebuild project I'm looking at changing from the 19/17 GSA spoked rims to 17/17 cast rims. That would let me put a 130 tire up front which in the world of sidecars is a good thing. On the front a cast R/RT/S rim is a nearly perfect fit. On the rear I'd need to go with a K12/13 rim as it has less offset than the R. The problem is the normal 180 tire would rub a bit unless I either relocate the exhaust 10mm or go with a smaller slip on. Of course my first thought was to swap the 180 for a 170, but in a pdf file that details converting the GSA to a supermoto it says the 170 is too narrow for the 5.5 inch rim and I'd have too much sidewall flex.

Has anyone tried this? How was the fit?

Pete and Glenlivet