I want to get carbon rims for my wife’s fat bike Farley 9.6. The wheels on there now are 27.5 x 80 mm If I buy 27.5 x 68 mm rims can I put 4.5 inch tires on those? Ideally I would like to just pull the tires off the steel rooms, and go tubeless. Peter Xu has those rims. The rear derailleur is SRAM GX. Does anyone see any problem with switching to these ?