I asked about how to fix wobbly mirrors a while ago, and had a go today. This is what I found/did, and will hopefully be of use to someone else.
This was on my 2003 foxeye, but may apply to other models.
First job was to remove the mirror assembly from the bike. There are 2 10mm nuts that are on the inside of the upper fairing. On the foxeye these are hidden by the infill panel, so you need to remove that too. (2 pozi screws on the upper face, and 1 4mm allen bolt on the outside of the fairing).
With the mirror off, you can wiggle/slide the rubber boot up the stalk, exposing the pivot point. From the factory this is held together by a rivet, which you may be lucky with, and be able to bend it in a bit to increase the tension. In my case I wasn't and it snapped on the first (gentle) application of the hammer. The rivet head fell of and bits pinged out. I think I found all of them.
Anyway, in my case, it looked like the reason for the slop was corrosion (which also explains why the rivet snapped. The inside of the joint as some steel washers (more on these later) which were quite rusty.
I now had a two parts to the mirror, the long stalk with the mirror on it and a short bit with the mounting bolts on. The remains of the rivet were attached to the stalk part, and needed to be knocked/pressed out. A quick check showed this to be 6mm thick, so that was the size bolt I used to rebuild it. I opted for a 6mm screw, to keep the head profile low.
Inside the assembly are 4 cupped steel washsers, that act as springs. I cleaned the rust off of these and applied a thin smear of grease to protect them and re-used them. Not sure how easy it would be to get new ones. They need to be put together in pairs, with the cups facing the opposite way (think of the smash robot heads). These provide the tension to hold the mirror in place, but have spring to allow movement to let you move the mirror.
Here are the parts in the assembly order, specifically - bolt/screw, washer (optional), mirror stalk, mirror mount, 2x pairs of cup washers, washer (to replicate the rivet head), nylock nut.
The picture doesn't show it, but the two halves of the mirror have a matching pattern/notches on them, that help to hold the mirror in position. These need to be mated together properly or it won't work properly.
Here is the assembled piece:
The nut shouldn't be overtightened. It needs to provide enough tension to hold the mirror, but leave some slack in the spring washers to allow you to move the mirror.
In Haynes manual tradition, re-assembly onto the bike is the reverse of the previous steps.
