Minoura Handlebar Mounted Smart Phone Holder (22.2, 25.4 & 28.6mm)

I purchased the STD size, to fit a 1" (25.4 mm) diameter handle bar. The kit has many parts to enable it to fit a variety of sizes, and it's a bit confusing to sort out which pieces go with which size. I used the "thin spacer" as directed, and assembled it. In the last step, in which the screw is tightened to bring the grip bars around the spacer, I tightened to a good tension, but the mount still moved around the handle bars with a press on the phone screen. I tightened further, testing whether it would not slip, to the point where I could not tighten more. Phone still slipping away when I pushed on the screen. I finally scrounged a small rubber section from a tube, inserted this between the spacer and the mount housing, and tightened the screw again. This time the screw did not tighten in all the way to the stop against the aluminum bracket, and the mount was tight on the handle bar. I understand the design that the company was using, but they didn't get the dimensions of the holder and the spacer done properly.

Update - Two weeks later, the mount suddenly started to roll around the handle bar (in the middle of a ride). I had to move it back to viewing position with my hand when I needed to see my next turn. Close inspection at home revealed that one grip bar was no longer on the "roll nut." After unmounting the mount, inspection of the grip bar motions revealed that there was too much splay range of the grip bars, and that one bar could pop off the roll nut.

Yet another example of the poor execution of the design by Minoura.
Do not waste your money on this mount.