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Discussion Starter #1
One on the last things to sort on my recently acquired 1000 DS was the horrible mirror shake that occurred from about 2800 RPM to about 3600 RPM. In lower gears the shake was not so much of an issue because the engine is not under much load, but in higher gears, and particularly in 5th and 6th, rolling on from 2900 RPM caused the mirrors to shake in a huge range of movement. The ends of the mirrors would bounce up and down, forward and back by a good 15mm or more.

I had read some things about tightening the mirror but this did nothing and I did not think it would. The issue was clearly that the stalk and mirror housing were simply flexing and experiencing resonance to the RPM of the engine.

I wanted to preserve the mirror mounted signals and I rather like the wide mirror so before moving to an aftermarket solution, but I thought that it might be possible to improve things by changing the resonance of the mirror stalk itself by shortening it. I mean I had nothing to loose because if I could not improve it, I would have to go to an aftermarket solution anyway, so I made the decision to make the change.

I took the mirrors off the bike. It is not necessary to disassemble the mirror housing itself. Just remove the mirror stalk from the handlebars and then drill off the heads of the rivets and push the rivets into the stalk. The mirror housing can now be pulled away from the stalk. It takes a little maneuvering to get the bullet connectors on the end of the signal wires though the hole in the mounting bolt but once done, you can pill the mirror housing away and clear the wires from the stalk tube.

I cut off 35mm from the mirror end of the stalk. At this point it is necessary to put everything back together and put it on the bike. Since the mirrors are lower, it will be necessary to angle them up a bit so set the mirror itself to a mid-range position in the housing and the while sitting on the bike with the stalk at the right angle, twist the housing on the end of the stalk so that it is angled up/down to a position that lets you see level and then mark the stalk. I did this with a power drill and bit using the holes in the mirror where the rivets go on the side facing me.

Now, pull everything back apart because the wires need to be out of the way to drill the new holes. I used a press and drilled the holes then re-assembled, and riveted the housings back on to the stalk, then re-installed everything.

How did it work? Well, all vibration is not removed for sure, but the resonant frequency was lowered down now to have a range of maybe 2700 to 3100 RPM and the amplitude of the vibration is greatly subdued. Getting it lower was important because I like using 6th gear above about 50 MPH and before, it practially had to be in 5th until about 60 MPH or the mirrors were useless, and the shaking was so bad I was afraid that in time the stalk would break.

As to the new position, I can see my bend in my arm when I have the mirrors set for my blind spots (which is mostly what I use rear view mirrors for) and to see behind me, I have to kind of lean a bit to the mirror I want to use, but I still have a very wide and useful field of view when seated straight up.

This was a huge improvement. Now I can roll on in top gear from about 50 MPH and experience minimal vibration and in lower gears it is more of a buzzy vibration than the large amplitude bouncing that I had previous to the mod.

So, practially no cost at all, and total time to do both mirrors was about 90 minutes.

If you have a lot of vibration and it is similar to my own situation, then taking 35mm off of the ends of the stalks might make a considerable improvement. I

Hope someone finds this useful.
 
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