V4 Warning! Monkey Boy Alert...

Is that not common, to use a left hand thread

 

I think most bikes with screw in type mirrors are L/H and R/H threaded.

 

I've never had one that's not L/H on the right and R/H on the left.
Prevents the bolts from tightening and stripping the threads when the mirror gets knocked.

 

And the wind loosening it ...

 

as said, std practice but irritating, comes under safety regs and not sure how many on a worldwide scale but:
"object must have compliance wherever possible* when struck from the front of the vehicle" ..or similar..

*i.e. - in this case, "undo" thread

 

I guess yours is going to get a right hand helicoil? Stick it to the man and his regulations..

 

agree - i even swapped left for right on one bike as no amount of Loctite* seemed to prevent one mirror arm being "blown" undone.

 

In bevel Ducatis, the nut holding the bevel gear onto the camshaft is left hand threaded. Not unknown for the hamfisted to ruin a camshaft ...

 

Don't left handed nuts have notches cut into them to help identify the thread direction?

 

Opposing threads for handlebar mirrors is the norm on many bikes, for the reasons already mentioned.