I'm running 27x12-12 Bear claws on 12x7.5 wheels on all four corners of my Rancher. My '10 Rzr S rims are 8" wide on the rear with 12" bighorns on them. Fronts are 6" with 9" bighorns, from the factory. You shouldn't have any problems with your rims. If you're still apprehensive, call a tire shop that deals with ATV tires. They'll be able to give you the pros and cons.