indianakid
Active member
The cause of fairing mirrors to be flopping is the threads stripping out of the mirror stem causing loss of spring preload. To correct the problem I oversized the threads to 10-32 and up graded the fastener to NAS1802-3-16. This about doubled the thread engagement / strength and allows proper preload to be applied to the spring. I also roughed up the mating surfaces to increase the coefficient of friction. The mirror is now back to blue print and stays put even at speeds in excess of LA freeway speeds.
How to………..
Drill out the 5mm thread stepping out in small increments to a #21 drill. The mirror stem is made of soft pot metal so when drilling out the thread, holding the mirror in one hand and the drill motor in the other things can go wrong. By taking small steps it reduces the probability of going off center or having the drill catch and go through. The existing hole in the mirror was about .6 deep. Tap 10-32 starting with a taper tap followed by a bottoming tap. Roughing up the outer surfaces with 60 grit paper aids in holding the mirror in position. Assemble the mirror with the screw and washer adjusting the compression of the spring as required so the mirror will be tight but not so tight as it cant be adjusted.
How to………..
Drill out the 5mm thread stepping out in small increments to a #21 drill. The mirror stem is made of soft pot metal so when drilling out the thread, holding the mirror in one hand and the drill motor in the other things can go wrong. By taking small steps it reduces the probability of going off center or having the drill catch and go through. The existing hole in the mirror was about .6 deep. Tap 10-32 starting with a taper tap followed by a bottoming tap. Roughing up the outer surfaces with 60 grit paper aids in holding the mirror in position. Assemble the mirror with the screw and washer adjusting the compression of the spring as required so the mirror will be tight but not so tight as it cant be adjusted.