Help choosing Fork Springs

[GTRider]

I am want to order fork spring for my 2003 CRF 450. The MX-Tech web site suggested .489 spring, I was wondering how much difference I would feel going from a .47 to a .48/.50. In looking at the fork springs that MX-Tech carries it looks like I need to order either the .48 or the .50 spring. which one to order? is the .48 going to be to soft or the .50 to stiff?

MX-tech recommended fork spring rate is....0.4898kg/mm
MX-Tech fork spring series is....43495xx

Thanks for your time,

GTRider

 

[shockdoc]

What is your weight and use of the bike? Are you also going stiffer on the shock? Makes a difference.


doc

 

[GTRider]

What is your weight and use of the bike? Are you also going stiffer on the shock? Makes a difference.


doc

Weight is about 240 dry and the main use is MX. I usually ride the B-class. The rear feel good, but might change it once I see how much inprovment is in the front. fornt bottems some but the rear I dont feel botteming out.

Thanks,
GTRider

 

[shockdoc]

I just did a customer who is 250lbs. He is not a fast rider and we used 6.0 rear & .50 up frt. A little soft but he likes it.


doc

 

[DEANSFASTWAY]

What shocdoc says sounds about right . I dont ever really end up going over >48 spring in anything uinless its a really heavy bike or rider. alot of fast guys are @200 lbs. Id rather see a bit more preload on a .48 or .50 than going any higher. did you ever check your fork sag with you loading the bike?if you run too much front spring on that 450 without setting the rear it could become a plow in the turns. you might want to try a heavier ICS spring in those forks also . It will have a bit of the effect of running more preload.GT, I would think that youll want to run a bit more on the comp stack so you might think about revalving a bit. Good Luck

 

[GTRider]

What shocdoc says sounds about right . I dont ever really end up going over >48 spring in anything uinless its a really heavy bike or rider. alot of fast guys are @200 lbs. Id rather see a bit more preload on a .48 or .50 than going any higher. did you ever check your fork sag with you loading the bike?if you run too much front spring on that 450 without setting the rear it could become a plow in the turns. you might want to try a heavier ICS spring in those forks also . It will have a bit of the effect of running more preload.GT, I would think that youll want to run a bit more on the comp stack so you might think about revalving a bit. Good Luck

A couple of questions on your post. What are ICS springs? I have never checked the FORK sag just the rear sag, how do I check it and what should it be? How do you set the preload on the springs?

Thanks,