GPS mount resistant to vibration? I like to ride with a bike-specific GPS device mounted on my handlebar or stem, so I can look at it whenever I want. I use Garmin eTrex 30 with a mount like this:

The problem is, the GPS device falls off the mount under strong vibrations, and the mount wears out pretty quickly (a few days of heavy riding), which leads to the device falling off even easier.
Which options do I have? Should I replace my GPS device (I like it very much, so I prefer not to) or is there some more sturdy mount, or maybe one with shock absorption?
I have exactly the same type of mount and the same type of GPS with it, and after a few years of use the contact interface has become worn out, just as you describe.
The problem was exacerbated by the fact that it was both the mount guides and the GPS unit's backplate grooves that got widened, so replacing just the mount part would not be very effective.
What I did was to use molding plastic that hardens over 24 hours. There are brands such as Sugru, Kintsu glue etc. that sell it.
Spread a very tiny amount of the substance along the rails of the mount, as well as inside the grooves of the device's backplate.
When hardened, the resulting silicon creates quite extra friction when sliding the device onto the mount. This makes the rattling go away, and secures the device.
Additionally I put some of the stuff onto the &quot;tooth&quot; that latches into the backplate (left side of your picture) and also the square &quot;hole&quot; in the middle of the mount so that it will take up some slack created by the wearing process.
The restoration has worked for me so far. I do not expect it to last forever however, but the procedure can be repeated later when the surfaces are worn again.
Even before I've encountered the problem with the worn-out mount plate, I've always used a piece of a thin cord to tie the GPS device to the handlebars. When I crash, zip ties that hold the mounting plate can snap if something strikes the handlebars (it did happen several times). The GPS can then fly away into an unknown direction if not for the cord.
The same cord is used to bear the GPS on the neck when I am off the bike (I once lost my GPS in the water when crossing/swimming across a wide smelly ditch in the middle of the night. I won't ever dare to hold a GPS device not secured by a cord).