Originally Posted by
ak08820
The arm was meant for a handlebar mounted mirror. For that the arm is a 6mm rod. I created confusion by mixing 2 designs in my response.
I understood that the 9-12" was for the bike. When you are testing the arm: I found when I designed my eyeglass-mount mirror, the thicker I made the wire arm, the heavier it was so the more it vibrated. So your 6mm diameter may change per testing. Follow my signature if you want to see my design further.