I wouldn't be afraid to use it. I know you aren't going to put it UNDER the frame rail, so I don't see how a rock could ever get to it. If it did, it would likely just dent it. A rock big enough to break or puncture it would probably never get launched by those little front tires, anyway. If this was a jacked up 4-wheel-drive going off-road it may be an issue, but I think it's OK stuff here. Bottom line though, Roger, do what you are comfortable with.