Pds Spring Rates?

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#1
I have a 99 250 EXC that I ride tight woods with. My weight less gear is 195. I've tried to set the sag on my bike and it seems to need a lighter spring.It has a PDS 2 on it now which everyone tells me that for my weight that is the right spring.My question is there anyone out there thats using a PDS1 or some other spring rate that works for a guy my size. My goal is to have the race sag at 100mm and the static around 35mm. My shock has been professionally rebuilt/revalved and all the bushings are in good shape so I don't think anything is a problem there.:confused:
 

Strick

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#2
I think you are heading in the wrong direction. You should need a PDS-3. What settings have been able to achieve with the 2. What I mean is how close (far) away from 35/100 are you?
 
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#3
Strick thanks for the reply. As I understand it race sag is more important, so when I set 100mm race sag I have to back the collar all the way out and the static comes in around 75mm. If I do the static at 35mm then the race is 108 and if I preload the spring more the it only seems to effect the static numbers. As I'm describing this I think I'm beginning to see your point that I may need a heavier spring. I was afraid to go to a heavier spring because I was looking for a more plush ride.I'm sure if I can achieve the 35/100 ratio that the ride will be fine, I'm just having trouble figuring out which way to go on the spring.
 
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#4
Originally posted by ROADRACER
Strick thanks for the reply. As I understand it race sag is more important, so when I set 100mm race sag I have to back the collar all the way out and the static comes in around 75mm. If I do the static at 35mm then the race is 108 and if I preload the spring more the it only seems to effect the static numbers.
There's no way to put this nicely, but you are doing the measurement wrong if you get those numbers.

Recap:
A) Put bike on stand, rear wheel completely off the ground. Measure distance from axle to a fixed point in the fender (result: A).
B) Take bike off stand, push suspension down, let come up but not bounce. Take the same measure(result: B).
C) Stand on pegs while holding yourself up with hand to a wall or fence(hands off the bars, all weight on pegs), have buddy take the same measure (you can have your buddy take also A&B so they will be consistent).

Static sag: A-B
Race sag: A-C (You might be using B-C right now, or just mistyped the numbers above?)

Increasing preload should DEFINITELY decrease race sag as well as static.

PS. I only say to take race sag while standing on the pegs so you get consistent results. That way you have your weight always in the same place. Moving only a little on the saddle can change the race sag numbers by several centimeters.
 
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#5
Originally posted by ROADRACER
I was afraid to go to a heavier spring because I was looking for a more plush ride.
Oh yeah, using a spring that is too soft will cause the ride to be less plush, since the suspension will be too far into the stroke (where the progressiveness will cause it to be harsher).
 
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#6
Anssi I appreciate the lesson on how to set the sag and that is exactly how I've done it on many bikes over the last 15 years. This bike has been problematic and those are the numbers that I've come up with.Thats why I posted the question.:confused:
 
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#7
Sorry to start educating people that are already in the know. Anyways, something is fishy about the numbers you posted, since there should be no way that the race sag increase while static decreases. That is why I suspected your methods.

Have you tried really putting on that preload even to the point of almost nonexistant static sag to see how race sag is then affected? At 35/108mm I think you still have some room to add preload in terms of decreasing static sag.