Spring reccomendation

[MonsterHPD]

Agreed, except the preload required to maintain correct sag on a softer spring, and the force to initiate movement might very well exceed the force to get the stiffer spring moving at the preload required to maintain sag. Once moving the rate is the rate.

My old DU-440 seems to damp fine with a stiffer spring Nick.

Well,
may be a case of bad thinking on my part, but anyway: since the suspension is not topped out, the bike will sit on the force provided by total spring compression ((pre-load + sag) x spring rate). Everything else beeing the same, I'd assume that a given amount of sag will be the result of a given spring force, regardless of spring rate nd amount of pre-load, as long as the sum is the same.

But in the end, testing and personal taste decides the issue.

In a force-vs. spring compression diagram, the springs will be represented by straight lines of different inclination; I'd assume that the lines will cross at the point of same sag, of course provided the same sag has been set?

If the suspension was topped out, like I think it is on small-displacement road racing bikes, the situation is different.

EDIT:
As is usually the case in mechanical matters, nothing is black or white.
Returning the spring diagram, with 2 different springs set to the same sag, the softer spring will have the flatter, less inclined line. This means, that at spring compression numbers less that that corresponding to the set sag, the softer spring with more pre-load will actually be stiffer.

I'm not sure how that will feel; one might think that wheel travel less that the static sag will not matter much, but maybe it does ...?   

[Howie]

The shock is from ECS, in stock, I fell to temptation.  Steve will give me any spring I want, same price.  As far as valving goes, yeah I agree with the stacks, but it will stay stock 'till the first service.  I'll go either with the 95 or 100 and leave it up to Steve.

Thanks all!

[ducpainter]

<snip>
EDIT:
As is usually the case in mechanical matters, nothing is black or white.
Returning the spring diagram, with 2 different springs set to the same sag, the softer spring will have the flatter, less inclined line. This means, that at spring compression numbers less that that corresponding to the set sag, the softer spring with more pre-load will actually be stiffer.

I'm not sure how that will feel; one might think that wheel travel less that the static sag will not matter much, but maybe it does ...?   

It feels...

stiffer.

Actually to my ass it feels harsher.

The shock is from ECS, in stock, I fell to temptation.  Steve will give me any spring I want, same price.  As far as valving goes, yeah I agree with the stacks, but it will stay stock 'till the first service.  I'll go either with the 95 or 100 and leave it up to Steve.

Thanks all!

He'll treat you right. He's a good guy.

[Howie]

Going with the 95.  By the way, Nate is correct and it might show up on the NH washboard roads.  The theory ain't that hard.  Application is with my limited riding skills.  Both Steve and Eric say 95 for me.  Can't go wrong.

Again, thank you all.

[MonsterHPD]

It feels...

stiffer.

Actually to my ass it feels harsher.

I figured this issue deserved a little bit of analysis, and as always there's more than immediately meets the eye....

Using fork springs as an example, I checked for 8.5N/mm and 10 N/mm. Assuming 0 preload for the 10N-spring, and 20 mm for the 8.5N-spring, the 10N-spring will actually be softer all the way to approx. 110 mm travel.   

I've not checked where this might lead transferred to the rear, with all the very progressive linkage and all, but sag numbers will give an indication: If the empty sag is small, and the loaded sag is high, the spring is too soft.

The rest is down to personal taste ....     

[ducpainter]

I figured this issue deserved a little bit of analysis, and as always there's more than immediately meets the eye....

Using fork springs as an example, I checked for 8.5N/mm and 10 N/mm. Assuming 0 preload for the 10N-spring, and 20 mm for the 8.5N-spring, the 10N-spring will actually be softer all the way to approx. 110 mm travel.   

I've not checked where this might lead transferred to the rear, with all the very progressive linkage and all, but sag numbers will give an indication: If the empty sag is small, and the loaded sag is high, the spring is too soft.

The rest is down to personal taste ....     

My take on the subject...

it's voodoo.

I can say that a soft rear spring preloaded to give a 'somewhat near' sag number will feel much harsher/stiffer than a heavier spring with very little preload. If that fits into the equation then fine. If not, it still doesn't change the 'feel'.

[koko64]

I've played with fork oil and springs, but anything more than that, I give to the suspension guy. There's too much to learn as it is.