Well there are alot of cylinder_walker Deeres, NH TR's and I'm sure just about every other brand out there with bent rub bars in their concaves from rocks, branches, or whatever. This doesn't stop them from running. Do the same to an STS and nearly all of the cast separator tines are gone off the rotor as well as a good likelyhood of many of the cast_forged finger sections in the separator grate being damaged.