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Old 12-17-2010, 08:16 AM   #1
The Griz OP
North Forest Rider
 
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Joined: Nov 2008
Location: Minnesota
Oddometer: 3,785
F800GS Fork Clack Noise/Feel Demistified

I have recently seen a lot of random mentions within other threads regarding the fork clacking noise/feel on the front end of the F800GS. Most of the mentions unfortunately have shown misinformation on the subject and/or shown someone altering components on their bike that have nothing to do with the actual instigator.

The fork clack noise/feel is absolutely without a shadow of a doubt not from the plastic x shaped spring guides that ride on the damping rods inside the forks! Those black plastic x shaped spring guides do not move on the damping rod, and do not make contact with anything other than the inside of the springs. I've been inside my forks 4 times. The black plastic x shaped spring guides "snap" into position on the damping rods as to not move. They don't move therefore do not hit the fork tube cap therefore do not make a clacking noise. I've marked up a parts schematic to point out the facts:





#3 is what certain people claim is the clack-making culprit. It is the back plastic x shaped spring guide. It has a small steel ring that sits inside it in a groove (#4). #3 with #4 inside it slides onto the damping rod. The damping rod, as you can see, has a groove where the spring guide "clicks" or "snaps" into position, FIRMLY. I suspect that there MIGHT be some forks that are coming from Marzocchi without one or both of the spring guides snapped into place. If you open up your forks and the back x shaped plastic spring guides move up and down on the damping rod, this means simply that they are not snapped into place on the groove on the damping rod. Snap them into place and you're done (it requires some elbow grease to snap them into place, but this is a good thing and how it was designed. Once they're snapped into place you will not ever have to remove them again. They should have been snapped into place at the factory). No little rubber pieces or other voodoo needed.

All of that said and demistified, I'd like to point out that I have gone for rides with both of the black plastic x shaped spring guides both unsnapped and loose on the damping rod and snapped into position. No difference. No change. Sounds and feels the same either way.

Why?

This is because the clack sound and feel does not originate from these spring guides! Or anything inside the forks for that matter!

It originates from the Brembo floating front brake rotors. Nothing else. The rotors float a bit more than others designs. So when you go over bumps you hear and feel "clack clack".

This is absolutely fact here folks. I've been experimenting with it for two years. I've opened up and altered fork components many times, tightened steering head bearings many times, etc, etc... The only thing that has ever cured it is removing or hindering the "float" in the stock Brembo front brake rotors. If you don't believe me, test for yourself. CAREFULLY go for a slow ride away from traffic with both of the front brake rotors removed.

Or, as a safer option, use some zip-ties to inhibit the excessive floating motion within the rotors:





What's that? Silence? Exactly.

If you want to permanently fix it, buy and install some aftermarket rotors of a different design (non-floating), or with less "float". Two companies I have found that make them: Braking and Lucas.

http://www.wunderlichamerica.com/mot...S/8130021.html

http://f800depot.com/twalcom-wave-front-disc-p-467.html

This is not "The Griz's theory" on the subject, or my "opinion". What I've stated above are the facts. Heed them and welcome to a clack-free world. Cheers.
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The Griz screwed with this post 12-17-2010 at 08:58 AM
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