It is a little disconcerting when the saw binds up, better be holding on tight. Regarding machine shops, the problem is most machine shops cannot do it with the tires on. You will never get a better balanced tire then one mounted and balanced at the factory as they match balance them, mine have very little weight at all on them. It does not hack up the wheel if you are careful, the wheel is not even clear coated in the center where you are cutting. When this set wears out, I will buy another set of wheels and tires complete, there is a Hummer dealer near by that sells them for $400 a set.