Originally Posted by dad2bike
I spent last night comparing the fork inners between my 2003 525EXC & my 690R. I'm so very happy with the plushness of my 525 forks.
1st thing I find out, the cartridge is smaller on the 690. Whoops. I guess this will not be a direct copy of the shim stacks.
It took me up until late last night to figure out how the 2 different diameter stacks compared. Got It!
I found I can closely match my 525 shim stack functions with all the existing shims in the 690.
Other items to be figured out. My 525 uses .48 springs. The 690 .52 stock. I will give my old set 0f .48 from my 950 a run for a bit.
Next difference is the oil level. Hmmm, the 690 had 115mm, the 525 is 140mm. Any thoughts on a good starting point? I was thinking of starting at 120mm.
The research I have done so far and the very limited information available leads me to believe that the 690 stock springs are too soft for me (240 lb advanced rider) and the at the very least the forks are over damped for fast compression. So...from what I understand of suspensions: If the spring is too soft and the damping is too high, then the forks will feel harsh. If you go UP with spring rates, increase float slightly, soften high speed compression and progressively reduce bottoming resistance reduce the harshness at the limits of travel. I have been tending to start with 110mm air gap and add oil to get the best bottoming resistance, with the intention to work up to the best air gap to help reduce the progressive spring rate at max compression travel. I can state with a great level of assurance... my point of view on this is purely my opinion and is only based from learning and applying to my bikes. This tool has been a invaluable tool: http://www.shimrestackor.com/
Does anyone out there have a inventory of the shims in the different years of the forks and shocks that they would be willing to share?
EDIT: Oh, and as a side note, I have to say that the Factory rally bike that I rode (thanks Steve) before I got my 690 was one of the things that led me to really really want one of these bikes. The factory race suspension is SO AMAZING on fast stutter bumps. The faster the bike is ridden, the better it gets and it REALLY likes it when you are on the power through all types of corners, just CLAMPS the bike to the earth. freaking amazing. HOWEVER... the "public" version of the 690 suspension is very much NOT what the rally bike is.... the next HOWEVER is I hope that I can manage to get the WP suspenders close to the factory stuff...