Rocky, rooty trail settings.

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#1
So what direction should you go to get your forks to work better in rocky, rooty, clapped out trail conditions?

Do you just lighten the hi speed stack?

Would removing the cylinder valve seals help this?

Other than a little "spiking" they work good on less "abused" trails.

They are '99 YZ forks with the mid-valves disabled, cylinder valve seals and RT pistons.
 

MACE

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#2
Jinkies Scoob, I'm chasing the same Grail...

I'd run the lowest tire pressure you think will work in the rocks. Push the envelope a bit when trail riding and figure out how low you can go. This helps on roots - hurts on steering precision and of course increases likelyhood of flats.

If you don't have ProTapers, ovalize the bolt holes in your crossbar so they can flex. I also use ProGrip Dualsport grips which are real cushy.

That Mobil One is really slick stuff. It's for real.

I think the RT CV seals are hurting you for stiction, but it is such a bitch to remove them I'd let them be.

I'm a grease under the wiper believer. Opinions vary on that one. Seems to reduce stiction. I have the original seals in my 98 - no leaks - believe it or not!

I'd try two steps softer on the RT CHx charts.

If your soft springs are too soft and stiff springs too stiff - run one of each. That's what I ended up with when I had GVs.

Have fun and please let us know how it turns out.


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MACE

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#3
Thanks for answering Mace. I had about given up on getting any input.

I run Pro-Tapers, Emig T-clamp with rubber mounted bar clamps and 12psi. in the tires. 12psi. seems to me to be the best all-around setting for my S12's.

I have been both ways on the grease under the dust seals. Right now I'm not running any. Maybe I need to.

Removing the CV seals isn't that big a deal and I think that might help with the "spiking" and "slap downs". I'm also having problems with harshness on "slap downs". In general, my forks seem to be resistant to any sudden changes and I'm thinking that might have something to do with loosing the additional blow-off with the CV seals.

Now, RT recomends going two steps stiffer WITHOUT the seals installed. So removing them is going to effectively do what you suggested to the "CH" stack. But, it will also effect the "CL" the same.

With that in mind, I have tried the M-1 ATF and felt that it did add some addittional damping. So would you suggest just leaving the stacks the same and trying the M-1 ATF or increasing the "CL" also?

I may also give the spring thing a try. The stock spring feels a little soft but, the .44's seem like they add to much.

BTW- if you still have the same seals in you aren't getting the daily recomended allowance of mud riding.
 

MACE

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#4
MTRHEAD, first off, I think you know at least as much about suspension as I do - so take my inputs FWIW...

I'd really like to see you just remove the RT seals and do no other changes so you can isolate the effect of that one change. Changing fluid and base valving is something you can do later without total disassembly. One of my problems with sorting my forks has been my propensity of making numerous changes all at once. This makes it so I never learn what any single change does. I also have a problem of riding in so many different terrains that it's hard to compare week to week (this is a wonderful problem to have don't you think).

As for my magic everyouthful seals. I'm replacing them right now along with new bushings. I expect the new seals will leak like everyone elses do....

I live in Washington State and ride year round. I KNOW mud. My favourite part is when you put your goggles on after a break and all the mud gets swiped off the back of your helmet - AND DOWN YOUR COLLAR... Yeeeee-Haahhh!!!



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MACE

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#5
I understand what you are saying, but I want to get them right fast. There are so many races this time of year I don't have time to test a lot.

Another thing is they work pretty good on a faster, less beat up course.

I could get lucky and have them work perfect after the seal removal. Nah, impossible.
 
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#6
I may be out of my league here but,

The dozen or so tries I have had looking for plushness on rocks and roots without causing a mushy ride have led me to this:

Back up and reduce the high speed stack - pull a few HS shims and add a thin crossover. Keep the low speed stack firm and clickers at a low setting to prevent the mushy or loose feeling ride. Raise the oil level for g-outs and use the softer springs.

Even though I weight 195 in gear, my riding style is smooth and rarely bottom out.

Gives you another perspective,

James Dean
 
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#7
Nah Jimmy, you be right in the mix.

Actually I think you gave a pretty text book approach to problem and other than running a heavier spring I think I'm there.

I weigh the same as you and with the additional hardware and fuel I think the heavier springs work better. With the stock springs the front end seems to settle in pretty deep.
 
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#8
Here is a theory, and thats all it is:

Soft springs shift steering geometry more (steeper) when you move forward on the bike. Since I like tight woods riding, shifting forward gives better turning. Shifting back (within reason) helps extend the front for whoops. Whoops are a small percentage of what I ride. Higher fork oil level stiffens the last 1/3 of the travel which has a similar effect to the stiffer springs. The majority of the time it will be using the less stiff rate.

In the shop the forks feel like firm damping and medium spring rate, but riding feels balanced without sharp hits.

Sometimes I feel reluctant to voice that stiffer springs aren't the answer for every rider. Seems that stiffer springs are the automatic fix for the general population. Just not for me.

James
 
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#9
MTRHEAD & Mace, Others...

Here's my stock '00WR400 fork valving. I was changing the front tire and was inspired by this thread and take a look. First time apart for this bike. What would you think about changing the valving for a softer ride through rocky and rooted sections?

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Starting from compression valve face- (8mm ID on all shims)

(6 shims) - 24 X .1mm (low speed stack)

14 X .1 (cross over)

24 X .1 (start of high speed)
22 X .1
20 X .1
18 X .1
16 X .15
14 X .15
12 X .15
11 X .25

18 X .50 (at base)
----------------------

Was considering taking the 12 X .15 and moving it below the 14 X .1 crossover. Shifting the high speed stack back by .15 and making a smaller crossover diameter should soften accross the range. Too much? Ideas??

I could just send the works to Jeremy and let a Pro do it, but it's sitting out there ready to play.
Hope this isn't breaking etiquette.

BTW whats the torque for the valving stack nut?

James


[This message has been edited by James Dean (edited 11-12-2000).]
 
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#10
Now you are in the same boat as me. What does what for sure and how much?

That is why I use the RT kits. The CHART.
 

MACE

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#11
All I KNOW is that you torque the nut to 48 INCH-lbs. Use some blue loctite too.

The rest of this is probably all wrong and is based on trying to read trends on the Gold Valve charts and a little bit of logic. I'm pretty short on the practical experience part.

I don't think you'll get what you want with a minor change to the HSC stack spring rate and an increased "crossover" distance.

I'd go more radical in the valve spring rate change.

Remove two of the LSC shims.

Leave the LSC clamping shim "crossover" as is.

Remove the 16 x .15 from HSC

Rember that the HSC is affected by LSC. The HSC never deflects until LSC has deflected by the thickness of the clamping shim. Only then does the LSC <oops, edit, that should say HSC> do anything. Remember too that the OD of the clamping shims has a great affect on the stack spring rate. Removing one 16 x .15 will affect the rate a lot more than removing one 14 x .15.

And yes, Jeremy's cheese valves are great. Gold valve documentation is great. I think Jer's valves are fundamentally superior and I'm getting close to being pretty happy with mine.

Now that 1368 needle - I'm not quite sure....

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MACE

"Prime Directive - Serve the public trust, protect the innocent, uphold the law."

[This message has been edited by MACE (edited 11-13-2000).]
 
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#12
That 1368 needle is easy compared to the subtle complexities here.


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Moving that 1 shim has 3 consequences that I can see. It looks like a significant change.

1)Changing the crossover from .1mm to .25mm is the big one. For the shims to open .25mm at the outer edge will only take the 6 LS shims to flex. Keeping the .1mm crossover would have taken both stacks to move past .1mm, LS and HS stacks.

2)The reduction in diameter of the crossover shim to 12mm allows the low speed stack to flex more like a stack of 4 shims. This matches your suggestion, Mace.

3)Pulling the 12 off the HS stack softens this stack slightly. Not nearly as much as a 16 X .15, though like you said. Maybe I will pull the 16 X .15 too.


James Dean

[This message has been edited by James Dean (edited 11-13-2000).]
 

MACE

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#13
My comments on increasing crossovers are based only on what I've observed in the GV charts and reading between the lines on this forum. Logically, you are correct. Be sure to let us know what you end up doing and your results.
 
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#14
I agree with Mr. Dean, the needle is simple.

Figuring out how to make a shim stack harder or softer by moving a stupid washer is much harder.
 
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#15
I'm just going to say the change your proposing will be quite noticeable. Maybe more than you think. Consider that your total crossover gap will be the thickness of both the 12-.15 and the 14-.1 unless you plan to remove the 14.

If what your after is a softer fork your gonna get it! I would like to hear how it works out.