Scatman;
I drilled and tapped mine and set it in with Red (high strength) Loctite, plus put a thinned hex nut under that to be sure since the metal of the cover was pretty grainy and brittle, as if investment cast. I used that for about three seasons with my Garmin 2730 mounted on the long Ram arm and that unit is way heavier than the Zumo 550 I use now. No problems at all with the Zumo. I did have some trouble with the 2730 causing the arm to self lower as I rode over bumps or RR crossings and solved that by making a rubber wedge to set between the bottom of the arm and the top of the reservoir cover. With either the Zumo or the 2730 the screen was "right there" in plain view, but not obstructing my driving vision or view of any gague or switch. You can buy a reservoir cover with the Ram ball already set in it, I think Cycle Gadgets may be one source; maybe Hal has one or contact Jon.
prs
I drilled and tapped mine and set it in with Red (high strength) Loctite, plus put a thinned hex nut under that to be sure since the metal of the cover was pretty grainy and brittle, as if investment cast. I used that for about three seasons with my Garmin 2730 mounted on the long Ram arm and that unit is way heavier than the Zumo 550 I use now. No problems at all with the Zumo. I did have some trouble with the 2730 causing the arm to self lower as I rode over bumps or RR crossings and solved that by making a rubber wedge to set between the bottom of the arm and the top of the reservoir cover. With either the Zumo or the 2730 the screen was "right there" in plain view, but not obstructing my driving vision or view of any gague or switch. You can buy a reservoir cover with the Ram ball already set in it, I think Cycle Gadgets may be one source; maybe Hal has one or contact Jon.
prs