Garmin edge 800 (and similar) how to stop it coming loose from mount

Nearly lost my garmin edge 800 the other week when it slipped out the mount after an off into the heather. It’s not the first time it’s come loose and seems I am not the only one. Reading the threads it seems no mount is capable of holding the device securely so I am thinking of making a 3D printed hook and gluing it to the device with 2 part epoxy and then bungee cord or similar to the bar as a secondary measure…like this idea from the office
I’m prepared to put up with the glued part sticking out my silicon case so long as I don’t lose the item. Any one have ideas for the cord makeup? I’m thinking 3mm max. diameter should suffice.
of course if someone has managed in another way feel free to advise.

get a better mount. sram out front mount and tate barfly and neither have shown any sign of loosing grip

Doesn’t the 800 come with a tether like the 1000?

I thought they came with tethers too?

Like this…here

It would take a hell of a whack to move it out of a barfly. Much sturdier than the little garmin mount.

seems ironic that the 800 doesn’t have the tether, although I don’t have mine to hand to check..just this photo
if it is does then that gets rid of the hook bit…but a better cord would still suffice.
Tethering seems to be the way to go, a new mount is not secure enough from what I’ve read and someway in the group having similar problems even with a k mount

How about this

http://i40.tinypic.com/fnv0xi.jpg

not a bad attempt at tethering the device but wouldn’t trust the rubber to hold out for long.