Do i need to revalve/shim?

Post by **Indawoods** » 05:02 pm Jul 19 2005

er.... that's not quite right either!

What I meant to say is this:

It moves the stack away from the valve or moves it closer depending on how you adjust it. This in turn adjusts you stack... er kinda. I know how it works but kinda hard to put into words.... proly why they didn't!

canyncarvr · Post by **canyncarvr** » 05:31 pm Jul 19 2005

Re: LSC and HSC.

My point was differentiation between clickers and shims. I understand there are H/LSC shim stack configurations..and yes, even MIDDLE-speed stacks.

Eric Gorr wrote: All Japanese dirt bikes have suspension adjusting screws that affect the low-speed circuits only.

And...

Eric Gorr wrote:
The external adjusters, low speed compression and rebound....

...both from his 'Video Suspension Tuning' write-up.

Why worry about it? For the sake of clarity. If someone says to soften the LSC on your forks...you would do well to ask if they are talking about reconfiguring a shim-stack on a dual stage base valve...or making a screw adjustment.

Post by **KDXGarage** » 05:50 pm Jul 19 2005

Sorry about that. We are sometimes know-it-all's, but not tell-it-all's.

Is there a part that needs further explaining?

Help me, help you.

Post by **Indawoods** » 08:27 pm Jul 19 2005

-LSC= low velocity (slow speeds - small bumps - shorter shaft travel)

-MSC= mid velocity (medium speed - medium bumps - medium shaft travel)

-HSC= high velocity (high speeds - large bumps - longer shaft travel)

And your right CC...
this is LSC for the compression clickers. But more of an overall adjustment or initial adjustment compared to changing the LSC shims would be. Heck... even changing the LSC stack changes the MSC.

It all affects one another to get very technichal about it.

This is the fun part... understanding it all. I think I understand it all but can I put it into practice with any effect is the question.

I think the best thing to do it...

1. Setup your bike to spec, ride it. Make note where it needs improvement.

2. Make an fairly extreme adjustment so you know your going in the right direction.

3. Correct adjustment depending on the results of step 2.

4. Fine tune from there. (oil level, Rebound and compression settings)

5. If you can't get there from here... time for a stack change.

I think you will come up with a suitable setup doing these steps if your springs are in the ballpark. Remember a woods rider needs slightly lighter springs than what is recommended for the track. If it lists .44's for the track, go with .42's and maybe even .40's.
And generally the LSC has more of an affect on MSC harshness than the HSC and can usually be tuned out with LSC tuning.

That's my take and I'm sticking to it!

Post by **KDXGarage** » 08:44 pm Jul 19 2005

-LSC= low velocity (slow speeds - small bumps - shorter shaft travel)

-MSC= mid velocity (medium speed - medium bumps - medium shaft travel)

-HSC= high velocity (high speeds - large bumps - longer shaft travel)

Low, mid or high is not determined by how far the fork tube or shock shaft travels. Those terms only relate to tube/shaft speed.

Examples of high speed compression would be hitting a log, big rock or rut.

Examples of low speed compression would be getting on the front brake to slow down for a turn or landing a jump.

For those who have ridden on the street, it is the difference in cruising up to a stop sign vs. hitting a pot hole.

It is more related to how long it takes the fork tube / shock shaft to travel the distance than how far the distance is. HSC = running over a 4x4 piece of lumber. LSC = riding up the face of a 4" high jump that is 10 feet long.

I hope this helps.

Post by **Indawoods** » 08:51 pm Jul 19 2005

Those were taken from suspensionnetwork.com

Post by **KDXGarage** » 09:42 pm Jul 19 2005

I believe my explanantion to be correct.

Damping is speed sensitive. To me, it seems the LSC, MSC, HSC comment section you posted could lead one believe it is partly due to the speed of the vehicle, which is not the case.

Isn't this stuff confusing, but fun?

Post by **Indawoods** » 09:49 pm Jul 19 2005

I love it Jason!
I love to be confused.... I'm an IT guy and I get my kicks solving crap!

Post by **KDXGarage** » 10:42 pm Jul 19 2005

Tom and I will help you out. He has helped me.

skipro3 · Post by **skipro3** » 11:44 pm Jul 19 2005

Inda:
Your step 4: Add oil viscosity to that oil level for some fine tuning. I've heard of guys working out their own by blending different oils to get to what they want. I lighter oil really does make the forks much plusher than a heavier oil.

Keep in mind with spring rates: a lighter weight spring can be harsher that a heavy weight spring. Sounds backwards, right? Well, here's why: A light weight spring will either ride lower on the fork travel (more sag) resulting in a shock with less total travel for your use. You are now already in the mid point of the fork travel so the remaining point is either going to be stiff based on the stack you use, or will bottom easily. Both of those things are harsh. Second, by adjusting the sag to compensate for a light weight spring, you force the shock to be very insensitive to the high speed-small hits that a gravel road or such will present. It is my opinion, that you should err on the side of a slightly stiffer spring than a softer rated one for these reasons. A fork spring rate should be considered based on the rider weight and the bike's mass. For the guys using a KX125 fork set-up, the KDX is much heavier and so is the rider. (Sorry guys, it's true; we are FAT!!! Well, compared to the 145 to 155 lb. kid who the KX 125 is stock sprung for)

So; what I am saying is: if you are experiancing harshness in the fork's action, go to a stiffer spring rate and use ALL the 12+ inches of travel to get that plush ride. Work on oil level, oil viscosity, stack configuration (a dual stage for plush and bottoming resistance), sag and clicker adjustments to get the stiffer springs to mind their manners.

O.K. I'm sure there will be rebuttal. So educate me!!!

Post by **KDXGarage** » 12:21 am Jul 20 2005

This idea does not account for setting the proper spring sag. If a too light spring is used, yes, it will sag (settle) more under the weight of the rider and bike. A certain stiffness is required to maintain height. For example, if you used a super long ball point pen spring, they would bottom out as soon as you got it off the work stand. If a "just right" stiffness spring is used, it will settle X amount. A "too soft" spring will allow it to settle greater than X amount. A too stiff spring will allow it to settle less than X amount.

On a too soft spring, it is OK for most hits. Again, this doesn't take into account proper weight balance of bike, etc. If you take a really big hit, it will bottom out sooner than the "just right" stiffer spring, which will bottom out before the "too stiff" spring, which will bottom out before the "way too stiff" spring, etc.

On the opposite side of things, the "way too stiff" spring will really beat you to death on little bumps worse than the "too stiff" spring which will only beat you to death some, which is worse than the "just right" spring which will be acceptable, and then there's the "too soft" spring which is better than "just right" on little hits.

You don't want tot jump a Cadilac and you don't want to take a super sports car on a cross country cruise.

ski, if someone has "too soft" springs, then they are surely already using all the travel. No need to reload with a stiffer spring and go for it again.

I guess springs are like Goldilocks and the Three Bears - too soft, too hard, just right.

They ought to sell springs in a three pack and let you return two of them.

canyncarvr · Post by **canyncarvr** » 11:42 am Jul 20 2005

Another example of 'words mean things'.

Yup.

As long as your talking about suspension it should be fairly safe to say,'slow, medium, high' speeds, because 'everyone' knows that the subject is suspension and 'speed' means suspension speed..having nothing to do with bike speed.

But,

Jason wrote: '..the LSC, MSC, HSC comment section you posted could lead one believe it is partly due to the speed of the vehicle...

.. is certainly true. Depends on the level of discussion you're having...or the level of the people you're discussing something with. The new reader would read the above quote reference and certainly think bike speed had something to do with it.

It don't.

..neither does amount of travel.

The issue is how much fluid is moved in how much time. How far the tube moves matters a whole lot less than the acceleration of the tube (thus volume of fluid past whatever restricters within a given time).

Kind'a like the difference between amps and volts!

Three pack? As in...mono-forks?

re: ' if you are experiancing harshness in the fork's action,'

Push the bleeder buttons!

Post by **fuzzy** » 12:12 pm Jul 20 2005

Isn't that the same thing as a RT delta valve? Regardless, there is lots of cool stuff on that page...

KDXRIDER.NET

KDXRIDER.NET

Do i need to revalve/shim?