Idaho-Thrux
I bought the Napoleon bar end mirrors from NewBonneville. I'd read the threads and knew in advance that some mods were needed.
What I didn't realise was that the bars are solid (showing my age I guess - bars have always been pipe section in my life).
Basically I drilled the existing hole in the end of the bar to 17/64" and then counterbored 1/2" depth of this hole to 13/32" (necessary to allow for the unthreaded part of the bolt). I then tapped the hole using an 8 mm plug tap. I used plenty of cutting oil - the aluminium swarf clogs the tap very quickly.
I then cut off the part of the mirror casting that goes into the bar.
From there it was just a matter of attaching the mirror using the bolt that came with it.
I could have gotten away with a shorter bolt . Having removed the insert friction is the only thing to stop the mirrror spinning on the bar I but I figured the longer the bolt the better. I used locktite on the threads and have now ridden 200 km and the mirrors are still tight. Time will tell.
When fitting the mirror I used the plastic and steel spacers that came with them. These serve to ensure that the mirror stands off the end of the bar a little and minimise any chance of fouling the end of the twist grip. Jamming the throttle open could be an interesting experience!!!!
The end result is I can now see where I've been and any four wheel drive about to tail end me at the traffic lights. Much better than a close up of my forearm. The bike also looks so much different. My wife says it looks lower and more broad shouldered. Couldn't have said it better myself
Anyway good luck with it