ConradM

I'm pasting this from the zx6r boards so some of it might be bike specific. Oh and as far as I know this works on most bikes except for late model CBR's.

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This is old news to track riders which I'm not yet, but I just found out about this easy little mod the other day. Basically you shim your rear shock to add rear ride height which in turn adds rake and trail. More rake and trail = faster steering.

This is similar to raising your fork tubes but with this method you don't lose any ride height. You could also do both which I plan to experiment with.

This is the factory shim on a 2004 636. I've read that the shim on the zx6rr is twice as big which confirms the validity of this mod.



You have to remove the shock clevis to add the shims and in my case the easiest way to do it was to un bolt the top and bottom of the shock so I could move it out of the way.

Easiest way to get to the top nut us from under the gas tank -



Loosen the top nuts and clevis nuts while the bike is up on the rear stand, then you have to support the frame before you can let the wheel down. I used some ratchet extensions in the swingarm pivot -



Also a good idea to block the front brake before doing that -



Here's the clevis separated from the shock. I just brought this with me to lowes to find some washers.



These did the trick -



I'm starting with 3 washers. If you're like me you're running a 70 tire instead of the factory 65 so really this is just bringing the rake and trail back within factory specs.



I got it all back together today and went for a ride up to my local mountain. Initial impressions are -

The steering is faster, marginally, I wouldn't call it twitchy at all. The 2 biggest improvements I noticed were mid corner stability and less understeer.

The bike is much more planted leaned over and when I would drive out of corners before, the front would want to push so I had to add bar pressure. Now I can drive out and the bike just keeps on it's line.

So that for those that like to tinker, this is a super easy mod that will bring results. Now as soon as I find a way to support the front of my bike I'm going to try raising the fork tubes a bit for even more rake and trail.

RedStar

Not sure this works on all bikes. I know we do it on our 03/06 636 for stoppies.

ConradM

As far as I understand the only oddballs are the RR's.

thedeatons

This works on all bikes with a clevis style shock. Old shoolers with eyelets top and bottom need to be modified in other ways, like using different length dog bones to alter rear ride height, etc...

James

scharf2u

fork tubes are easy. Just do one at a time the tight one will support the bike while you raise/lower the other then repeat.

thedeatons

I use a machinist ruler for fork tubes... Using the 32nd or 64th scale. I measure from the top triple clamp to the seem between the fork tube and fork cap.

Always roll the front wheel after tightening everything to make sure there is no binding...

James