GSX 750 Mod Shock Adjustments...

[canyonbreeze]

I got a 89-92 GSX 750/1100 Shock off eBay pretty cheaply.  Filled with DOT4 brake fluid and had a shop charge the nitrogen to 150 psi.  Fit in the B400 with no modifications at all.  Attached the remote reservoir up under the seat next to the right grab bar using cable clamps.  All seems well but I don't notice much difference in how it rides from the original shock.  Can someone give some tips on what adjustments to make and how to make them?  Thanks.

[tomacGTi]

Filled with DOT4 brake fluid

If you did this, you might as well throw the shock away. The internal seals are not designed for brake fluid and will swell and fail. You should have used 2.5wt suspension fluid or even lighter in some cases.

Barring that, I know I didn't record my settings when using that shock but I know I did have to use a good deal of preload as well as rebound damping to get the shock to work the way I wanted it.

Google suspension setup and you'll have literally pages of information.

[interfuse]

Here's a page that talks about the various settings of the shock.

http://www.bikepower.net/gs500e-power/modifications/suspension-related/gsxrshock/gsxrpage3.htm

[canyonbreeze]

"...you might as well throw the shock away. "  --  Interesting.  Both the seller of the shock and my local mechanic said to use brake fluid in it, also the shop that did the charge said that was fine.


Seems I got bad advice and will now need to part with more $$$ to get it cleaned out and re-recharged.  Dang.  


Update:  Took it to a suspension shop to open up, flush out, check seals, etc.  If will rebuild ok, great, if not then I'll toss it.

[tomacGTi]

Like I said, I have never heard of using DOT4 for anything but brake fluid or in some cases fluid for a hydraulic clutch designed for it but never for a suspension application.

I may be wrong but keep an eye on the seals and see. If they let go, then there's your answer.

[canyonbreeze]

I think I did my last edit at the same time you posted.

[canyonbreeze]

Turns out the shock has a bad shaft internally anyway and is a throwaway.  Waste of time and money.

[canyonbreeze]

Tried again with a shock from a 2006 GSX-R600.  This one has the fixed reservoir at a right angle to the shock.  The coolant overflow tank needs to be removed to make room for it.  I made a temporary overflow from a vitamin bottle until I come up with something more eloquent.  

To install the shock you need to remove the air box and loosen the battery box then work it down from the top. The bike is sitting an inch or two taller which feels good for me.  The rear suspension feels A LOT better to me.  The front suspension however feels a bit worse.  I assume it is "over-preloaded" now and if anyone has tips on adjusting that pleas chime in.  The center stand is also a little closer to the chain on the edge so I'm going to cut a little of the center stand metal pad off for clearance.

[canyonbreeze]

New coolant overflow made from PVC pipe painted black.  Mounted to frame behind radiator.

[Herr Tod]

I moved the battery back a little bit when I did this mod long ago. Gave just enough room to keep the stock coolant reservoir.





I also had the centerstand on the bike back then, but I removed it because it kept hitting the ground no matter how far I was hanging off the bike. Haven't missed it ever since.