Forks harsh

[turbomart]

I recently aquired a 01 650 & noticed that the suspension , particularly the front was very harsh.Did some research here & it appears a common problem.I decided to pull my forks apart & see what could be done .What I found was someone had already been in there & fitted new longer spacers (I think).Spacers are 120mm long steel tube.Trouble is to ensure spacers push on spring they fitted washers above & below spacer which did not positively locate & moved to one side causing spring to be bent & also jamming on the plastic spring guide in the centre when trying to compress more than about 1/3 to 1/2 of travel.
The other thing was the oil looked a lot thicker than the 5w that Id bought , in fact it looked thicker than the 15w that I used in my other bike (95 yamaha YZF600R).
So as a temp fix I fitted larger washers that cant slide to one side as they only just fit & put it back together with 5w oil to stock specs otherwise, ie air gap & preload thread screwed into cap.

This resulted in a huge improvement to the ride, but I believe going to an even lighter oil will improve things still further.Im going to try 2.5w and see how that goes.I read up on shocks & it seems oil viscosity tends to affect low speed damping more & it seems to me that its the high speed damping thats still to harsh in compression but I reckon being a little t soft at low speeds is probably not a issue.
Btw rebound dampening is still more than adequate & I cant see it being a problem with the thinner oil either.
Also to note, it appears from my research that oil viscosity varies enormously from brand to brand regardless of what weight is printed on the bottle, ie some 5w oils can be as thick or sometimes thicker than 10w.

[weirdo]

http://www.raptorchapter.org.uk/viewtop ... =16&t=2436

There y'go mate, the info in this thread might help get you where you want to be