The fitting provided with a bar end mirror is not substantial enough to withstand vibration and wind pressure leverage. The best way to overcome this problem is to go to your local builder’s merchant or do-it-yourself store and buy what is called a “loose bolt Rawlplug”. These expand just like the bar end fitting but are cast metal and not a bit of bent tin! They come in various sizes and so you can fit them to a 7/8″ or 1″ bar.
The only mod you need to make to the mirror arm, is to open up the hole to take the metric bolt provided with the Rawlplug. These really grip within the handle-bar.
Dave
