On my XR650 I've got some crappy Chinese knockoffs. As soon as I hit big bumps or the highway and bump up to 75 they fold in, or the mirror twists, or something. Basically, they suck. When you tighten them down the crappy ball mount bends, and it gets worse.
Anybody have something to recommend? The stockers are long gone thanks to the first own who ran it on a farm- with no mirrors.