I just have a cheap plastic bicycle mirror on my xb9 and it works perfectly fine. It was just supposed to be temporary since I had it sitting around, but it works so well I've just left it. I can't see the listing while I'm at work, but there's a ton on ebay that go for $18 shipped for the pair, so I'll probably just grab a pair of those someday. No real vibration problems or anything on mine so I can see at any rpm.