This mount is very sturdy/well-built. It works great for a Delorme Earthmate GPS. It comes with u-bolts of two different sizes so you should be able to place it anywhere at all on your handle bars. The u-bolts aren't big enough to place around a stem but that would seem awkward anyway. I was initially waffling between this mount and one of the quick release ones. I wanted quick release but that mount didn't sound as well-built. The GPS holder and arm with tightener and two swiveling balls are essentially quick release. Just loosen it all the way and the whole thing comes off the u-bolt mount (which does stay on the handlebar unless unscrewed with wrench). The good thing is that removing the part that does come off easily gets everything out of your way if you don't want it there for some reason.
While this one is designated as the motorcycle mount, it works fantastic on my mountain bike. And honestly, I was extremely impressed with how securely the cradle holds the GPS. It's absolutely not going anywhere. And the swivel on each end of the arm gives a lot of freedom as to where to have the cradle positioned.