I have Doubletake RAM mount mirrors on my 500EXC. When off-roading on rough terrain, they tend to fall down a lot. I tightened them with Vice Grips to the point where the balls are all distorted, and now they almost stay put. They might be fine for on-road use. However, if they must be loose enough for frequent manual adjustment, they would probably get pushed around by wind at 65MPH.