I found that it narrow end - where the zip tie was screwed into the housing - was a weak point, and would break off over a short period of time. So I discarded that original arrangement.
Instead I have a strong zip tie looped through the hollow pivot of the mirror mount, zipped to itself on the outside.
Another strong Zip tie loop threaded behind one of the three mounting posts for the indicator light. You have to slacken the screw to thread it behind the post. Again, zipped loosely to form a loop.
The original releasable Zip tie is used to link those two lops to prevent the mirror housing hitting the ground..
Someone once pointed out that this method introduced three potential points of failure, rather than just one. But it has never failed on me. The original method - the zip tie cracked every time near the screw on the mirror housing. (Four mirrors, two bikes. The first few times, I cut off the cracked end and drilled a new hole. to effect a repair, but it soon cracked again. The problem is that the load is at right angles to the screw head, and I have a standard Uk garage - wide enough to fit a car, but barely wide enough to open the door to get out. So the car has never been in the garage. But squeezing past the motorbike often results in the mirror housing being knocked off. It gets a lot of testing!
