I got the bike mount for my Etrex Vista. That was the worst thing I could do. The vibrations would shut off the unit quite frequently. I would be riding and look down and it was off, missing all the track data. Also now the unit has problems from time to time. I would try and find a different method of mounting. Now I clip it to my back pack. That doesn't allow me to view it while I am riding but at least it stays on.
Brad