I recently bought some replacement mirrors for the nasty old ones on my '85.
The replacements were pretty and clean.  I tightened the nuts on the springs
to make sure they didn't tip in the wind, but it didn't work -- they still
folded a bit.  I took them apart and first thing I noticed is that the springs in
the new mirrors aren't nearly as beefy as the ones in the old mirrors.  I
swapped them out and now the mirrors are rocks.  I also roughed up the ball and
socket inside with a bit of sandpaper, just to make sure.

I use 4" fish-eye mirrors on each side, and they are the best.  I can see
cars beside me as well as behind me.  Once you've had them awhile, and you get
used to them, they are indispensable.

Terry K had a great idea for his sloppy mirrors.  He pulled the stud out and
tapped the hole for a 1/4" bolt -- you can tighten the daylights out of it.
Nice.

Bill Marshall
85 GL Tiico "Pandora's Box"
Aurora, IL