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Fork oil weight for heavy springs?

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My 2003 XR250R was sprung way too soft when I got it, I weight 253lbs (plus gear). So I installed some Eibach .47kg front fork springs and a 12kg rear (I got the heaviest springs available, I think stock was .38kg and 11kg), and now it's almost perfect as far as spring rate for my weight. The problem now is that the front fork only has compression damping adjustment, no rebound. With the heavier springs the front seems to rebound too quick, which makes for scary stuff in certain riding conditions. The stock fork oil is SS7, which I guess is 5 weight? I picked up some Motul 10 weight fork oil, would that increase the rebound damping? Would 10 weight even make a noticeable difference over SS7? I don't want to make a huge change, but I'm not sure how much the oil weight will affect the rebound damping.

BTW, I will be riding primarily in the CA high desert and on trails around Silverwood Lake (mixed terrain)

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there will be a difference to the stock oil. I cannot say if a 10wt is better than a 7.5 or maybe a 15wt is the oil to go for. I would give the 10wt a try...

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the heavier oil will flow slower through the stack and make for a harsher ride. I used 5wt. in mine. .50kg front springs and a 6.0 on the back. and i way 263lbs. put 20cc less oil in the forks. had bottoming problem so i added 10cc more back to each fork and never have had a problem again. Not sure about your settings though. I have 10 clicks on the rebound and 12 on the compression. started on 12/12.. but it was to harsh in big braking bumps. not sure if it helped but that was my experience.

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I think I am going to end up taking my forks to XR's Only tomorrow. They said $160 to revalve them, and about $60 more for new seals and oil. I think that will be a better way to go, because like you mentioned, if I just run thicker oil it will not really do what I want it to do.

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