Mirrors - what am I not grokking

Hi all -- I have factory mirrors on my 2014 GRiSO, and one of arms folded in during a ride. Upon returning home, I figured it would be a simple tightening of the top nut (guessing one of them is a compression nut), but it wouldn't budge at all. The other mirror is pretty much the same, where putting a pair of 19mm wrenches on both nuts results in nothing loosening.

Is there something super easy I'm missing here? I'm hesitant to put a lot of force into it because I'd rather avoid needing to buy parts if I break something...

left hand thread

That would do it...

Don’t think it’s a LHT.

The way the mirrors are secured is that the stem pokes into a split olive in the lower part of the mount. The top part is tapered to squeeze the leaves of the olive together as it is tightened down so they grasp the stem to prevent it moving. At least that is the theory…..!

The thing is mirror assemblies are cheaply made and manufactured so the olive may be slightly undersized or the taper on the crushing nut interior slightly too large so there is not enough thread available to close the olive tight enough on the stem to to hold it tight enough to overcome wind pressure or whatever. Also if they get knocked a few times the stems may wear, or the olive, and over time they will get looser and looser.

The solution is actually very simple. Undo the locking nut and remove the mirror stem. Remove the locking nut completely exposing the olive. Now get a small piece of shim stock, or just use an off-cut of an old feeler gauge, it only needs to be a thou or two thick, and wrap it around the bottom of the stem of the mirror after threading the locking nut onto the stem and pushing it up out of the way.

Now slide the mirror stem, wrapped in the shimstock, into the olive and drop the locking nut down to the olive and tighten it. The extra diameter of the stem added by the shimstock means that the olive will grasp and lock the stem before the locknut runs out of thread or the olive runs out of *Crush*.

Adjust to suit and ride off into the distance!

After experiencing the same issue, too many times, I bought a pair of lovely bar end mirrors. Spendy, and worth every penny.

It seemed every time I had a mirror problem, I was far from home and only had one wrench large enough to adjust them. No more.....

My issue is I hate bar end mirrors with a burning passion hotter than a thousand suns!