Re: Mirror Wars

[dan & ann curcio <curcio@xxxxxxxxxx>]

Paul,

I thought about this as as well.  It appears that the mirror and fairing vibrations are due to a combination of road vibration, air turbulence and the length of the mirror stems.  After the ride today it became apparent to me that the faster the bike is ridden the more the top of the
fairing is pushed down and the frequency of it springing back increases.  Once some engine vibration and road irregularities are thrown in the whole thing starts to dance quite well.  I have found the side to side shaking not to cause as much problem as the downward compression of the
windscreen area. I wouldn't have a clue as where to even start looking at the aerodynamics involved.  I was thinking of trying some trim tabs on the fairing extensions and windshield.  All I know is that the taller windscreen worsens the problem.  Anyone have a wind tunnel I could
borrow?   The brace I made was actually a very light weight aluminum angle extrusion.  It may have added an ounce at most to the weight of the fairing.  I have come to the conclusion that the bracing for the fairing is susceptible to harmonic or sympathetic vibrations so my goal is to
change the frequency of the mirror bracing to try to solve the problem.  I haven't had a chance to pull everything off to get at the mirror supports so I don't yet know if changing the bracing is possible.  Before I disassemble everything I am going to try riding the bike with no
windscreen to see what happens.  The sad thing is that Dave's idea of putting a couple of large rubber bands over the fairing extensions would probably work quite well.  As for the aesthetics, at least it would be a good conversation starter.

Thanks for the input,
Dan

Danilowicz, Paul S. wrote:

> Here's something to think about....
>
> I've seen many times that people jump to the conclusion that the solution is to make something stronger, stiffer, or bigger to fix problems.   If this problem is an aerodynamically induced oscillation and not road vibes,  then fairing stiffeners may not be the way to solve the problem.
>
> Perhaps, a small trim tab, spoiler, or some other aerodynamic stabilizer is the key.
> > Paul
>


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