Mirror Adjustment Question

[LongRanger_imp]

Yep, I stand corrected. Interesting that you mentioned Yamaha. The last time I struggled with mirrors was with my ‘73 RD350. They were indeed threaded differently.

[GoldOxide_imp]

Yep, I stand corrected. Interesting that you mentioned Yamaha. The last time I struggled with mirrors was with my ‘73 RD350. They were indeed threaded differently.

I vaguely recall fussing with the mirror on the '76 RD400. In addition, the bike did not come with a right side mirror - but the law at the time said a left mirror was mandatory.

[pekingduck]

I’m pretty sure the R mirror has the reversed threads. If you’re sitting on the bike, you can push the R mirror away from you and the stem will tighten. Pull it towards you and it will loosen.

If you push the L mirror away from you, it too will tighten, because its threads are normal, not reversed. Pull it towards you and it will loosen.

No, not correcting you - you are right, in that because each mirror assembly has a left and a right thread. They should move in either direction, depending how it was tightened at the adapter or lock nut. Pull it towards you, and one thread wants to tighten, the other wants to loosen. Pull it and the opposite happens.

[j3gq_imp]

My two bits to this story: while we always assume right (hand/side) or left (hand/side) is clear enough and universal - It is not. In order to define right or left one always needs to add an axis and a direction (meaning a vector). The standard convention on screws could make you believe ... "hey, a right hand screw, ... right ? IMHO two out of ten readers will be confused with this solution too.

About delta's OP, forget about spanners and how to save the nuts shown in the picture - that is too late.
If you can't replace the mirror (the best idea), if you have to fix the one you have, do this:
- hold the "upper or top-left nut" tightly with a solid vice (hopefully attached to a solid work bench),
- take heavy pliers, tighten with both hands and turn left (and applying what I said above), turn left here means : when you look down the mirror arm from the nut's end you turn against the sense of the hands of your watch (hopefully not an Apple watch).

[Charlie Bravo_imp]

Left hand threaded fasteners have a notch cut in each corner of the hex shape so you can tell if the thread is "backward". Some industrial equipment has "backward" threads that are marked as such. If you want to save that fastener, dose it with WD and let it sit overnight, then tap it lightly to set up a vibration to get the fluid to seep into the threads.