Seal Savers / Stiction / Shim stacks / Bladders

Questions and comments about converting to beefier forks..
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Post by KDXGarage »

OK, I didn't see the edited part. Thanks for the re-post to make me get an e-mail notification.

I have already exceeded my alloted amount of time to spend on being concerned with said person and site for today, so PM me tomorrow. :grin:

I sure as hell hope you get an axle and spacers soon. I thought "I" was a worry wart! :grin: You need to bolt them on, go for one of your normal 75 mile rides, then go from there.

As far as Forslyk, that guy said one shop had one bottle to do 16 bikes. That means it can surely do 10 bikes. Someone needs to buy a $50 bottle, do their bike, sell it some other member for $45, then they do their bike, sell it for $40, etc.

I thought I sent you some bladder pictures. Did I not??

KYB service manual? I wish! I guess fork manufacturers leave it up to the manufacturer to provide the documentation. The most current fork service information in a manual that I have is 1990 KX125 and KX250. Those are a great many years from 1999, I am afeared.
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Post by Indawoods »

re:Bladders

Not in my fork... are proly in yours. The bladder does not look like you'd think it does... it basically covers the whole bottom cartridge... like YES a forskin! :lol:
Weird looking setup and if I had em on mine... they'd be gone due to all the bad press. Have you pulled your cartridge out CC?
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Post by Indawoods »

A must read on bladder design CC:

http://www.mx-tech.com/articleread.asp?ArticleID=15

Here's a partial pic...
Image
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Post by KDXGarage »

Is that the bladder out of your forks?
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Post by Indawoods »

And finally... how to disable and fix the bladder forks:

First take the forks apart. Once the spring and cartridge is out take and carefully pull the dust wiper out. Now take and slowly pull the fork apart untill it stops. Don't slam or hammer them. Once the fork is pulled all the way apart you will notice that the chrome stops and there is almost a slight edge and then discoloration. Take some good seal grease (I use Torco) and smear on the fork tube right where the chrome ends. Then take and spin the fork tube and work a small amount a grease into the seal (while its still installed) and also on the dust wiper. Don't gob it in but just enough to lube the seal. Now put the wiper back in and wipe off the excess.

These forks don't have the washer sitting on top of the cartridge like the previous years. That piece (CV valve) the spring sits on top of the cartridge will tap off of the cartridge. Inside it is a cpl special washers and a spring. You can just simply take these pieces out, tap the spring holder back onto cartridge and thats it. You can leave the bladder in and just set your oil level like you would for a normal KYB without bladders. Instantly good working KYB's.

If your still confusED... read this since that's where I got the info! :lol:
http://www.thumpertalk.com/forum/archiv ... 86268.html
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Post by skipro3 »

I'm not sure mid-valve (bladder)harshness has anything to do with stiction caused by the fork seals working along the inner tube. The forslyk stuff is being compared to titainium nitrate coating, performance wise. It's a friction reducer.

As far as I can tell, my forks, 1996 KX125's do not have mid-valves or bladders (one and the same, right?). Is that correct or am I lost again?

Chris, the guy at Forslyk I have been e-mailing, and I have been comparing notes on shim stack real world performance. It is his opinion that the 2 stage stack causes harshness right at the mid stroke and that for a truely plush feeling fork action, a single stage stack is better. (If anyone wants a quick lesson of what a multi stage stack is, check the suspensionnetwork website and click on the shim program link in the menu on the left. There's TONS of info there.)
Anyway, my harshness is felt from race sag height on smooth fireroads over rocks and small ruts. This is the area for sticktion to be at it's worst; right when the fork seals start to slide on the tube. With these small, fast hits under these riding conditions, the forks feel like they are not bounding up and down at all. And that is where Chris says his product will help.

If I repeat myself, (I know I am) it is to make sure I have explained my situation clearly. I sometimes cut important corners when typing.

With ALL that said, I LOVE my forks. If they never improved performance, they would still be WORLDS better than the stock KDX forks.

****EDIT****

One more thing: I was in communication with Chris and Forslyk long before the DRN thread. Just to clairify. I first saw Forslyk on ebay, contacted the seller and Chris has taken lots of time to reply to my queries and has directed me to other sites where it is being discussed and evaluated.
Last edited by skipro3 on 09:17 pm Mar 30 2005, edited 1 time in total.
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Post by Indawoods »

midvalves=bladders? No...not at all. A midvalve is hardware, and a bladder is rubberware! :shock:

That's interesting that (Chris) would say that a single stage setup is more plush.... every shop says different. The dual stage stack is supposed to be better for woods riding due to it's sensitivity to small bumps.

BTW... I love suspensionnetwork... something that has been needed for a long time... just wish it was totally free... like my site. :wink:
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Post by skipro3 »

Here's why he says the single stage stack is better for woods and why the 2 stage stack was even established: (Paraphrased from several e-mails)

First, 2 stage stacks are designed to have a soft action on small hits and a firm action when you hit something big. (Like the face of a triple jump, OW!)
Since, as woods riders, we probably will never recreate the situation of such large hits as this, the stiffer second stage is being felt as a mid stroke, harsh hit.

When the first, lighter stage of the stack finally contacts the first washer (spring) of the second stack, a distinct, harsh action is felt.
By designing a single stage stack that has all the plushness of the first stage of a 2 stage stack, and then stiffening up the action with prgressively robust springs (washers), You, as a woods rider, will be able to realize the full fork travel of your KX forks.

The ride on the KX forks with this type of single stage stack should ride a bit lower once under way. Sag should not be affected though. If your bike starts to sag too much, that's lost fork travel. Why give that up? Keep that clear; soft dampening is not soft spring action. Don't get those confused.

****EDIT****
I almost forgot; Chris's assesment of the single stage shim stack being plusher than a 2 stage stack is based on using Gold Valves and running 7wt oil, as well as using Race Tech's on-line chart for calculating your individual shim stack. (But you can't blame Race Tech for suggesting a 2 stage shim stack. Afterall, they are moto-x forks and they aren't anticipating that they are being used on a trail bike in the woods where the average speed is around 15 or 20 mph. Sorry I left that out. (I warned you eariler that I tend to leave important details out.)
Last edited by skipro3 on 09:56 pm Mar 30 2005, edited 1 time in total.
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Post by skipro3 »

Indawoods wrote:BTW... I love suspensionnetwork... something that has been needed for a long time... just wish it was totally free... like my site. :wink:
Inda, folks who find your site helpful should not take advantage of your hard work and recognize it has value by touching the little white and blue box at the bottom of this page. Of course some folks will exibit borish behavior and ignore the opportunity. It's how we can easily spot the better person.
Last edited by skipro3 on 09:53 pm Mar 30 2005, edited 2 times in total.
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Post by Indawoods »

Ah... Gold Valves... I still want some!
Makes sense Ski and something to keep in mind. 2 stage stacks start to get confusing anyway from a tuning aspect. I guarantee I can make a plush single stage stack! May bottom like a sack of rocks... but plush on the way down! :lol:

Check these out guys...
http://www.cyclewerksracing.com/ultra.html
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Post by KDXGarage »

Just to second it, bladders are not the same as midvalves. Midvalves are a spring and washer type of arrangment. They are on the damper rod of a cartridge fork. From the factory, 1996 KX forks had midvalves, but no bladders.

From most of my reading, a single stage stack is SX, with two stage being normal. Three stage stacks are also sometimes used. You can make how many ever stages you want, but at some point, it starts to behave like a single tapered stack.

"First, 2 stage stacks are designed to have a soft action on small hits and a firm action when you hit something big. (Like the face of a triple jump, OW!)
Since, as woods riders, we probably will never recreate the situation of such large hits as this, the stiffer second stage is being felt as a mid stroke, harsh hit."

Try to think of the speed that the fork or shock compresses or rebounds insiead of small hit / big hit. When hitting the face of a jump, the speed of the compression is low, thus it is called "low speed compresion or LSC". Rocks, roots, etc. cause HSC. When oil is forced through the valve it pushes the LSC stack away from the face of the piston. If it is pushed hard enough (on a HSC hit), it will come into contact with the second stage stack (HSC compression stack).

skipro3, have you considered trying to modify your HSC stack (assuming you have a two stage stack)? Removing shim(s) or using thinner shims may help you, and would cost mostly time and effort.

Again, try not to worry about speed of the motorcycle. Think speed of the suspension component's movement.

Just for example, since I know you have a street bike, when you are zipping down a road and see a red light and you hit the front brakes, the front end probably dives like an Olympian. This is LSC. Hit a pot hole at the same speed, HSC. There are some tutorials on the Race Tech site that give some good advice, too. I love reading about all this stuff, so I am always trying to find new stuff to read.
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Post by Indawoods »

skipro3 wrote:Inda, folks who find your site helpful should not take advantage of your hard work and recognize it has value by touching the little white and blue box at the bottom of this page. Of course some folks will exibit borish behavior and ignore the opportunity. It's how we can easily spot the better person.
Ski.. This is where character shows it's face. My boss and I have this discussion weekly about character and integrity. When you start getting older you realize what your really made of, what you stand for and what is really important to you. When you do the right things and are consistent and reliable.... you have integrity and you character starts to show though.
It's funny because this all goes back to the "Golden Rule" we were taught in school but didn't think too much about.
You know me... I try not to toot the donate horn too much because I want people to have fun first and foremost and I decided when I started this that it was going to be a complete 180 from DRN and I think I have accomplished that. Showing my character now... :lol:
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Post by IdahoCharley »

I've messed with the shim stacks on the two KTMs (WP 50s and WP 43s) I've owned and have learned a lot. Still have lots more to learn.

I've tried single stage and double stage and even played with a triple stage stack. The single stage stack once your close is easiest to fine tune. The double stage is at least 4 times more difficult to get dialed. Start playing with mid-valves/check plates and different gaps, different shim stacks, throw in some stiffer or less stiff springs; change oil viscosity; air space changes and you'll understand why professionals charge what they do to dial your suspension. My suggestion to everyone playing the shim stack game and playing with oil viscosities and oil heights is to keep good notes. You will start to confuse yourself after about the tenth change. Suspension stuff is fun to play with but very hard to get your head around.

Now they have a bladder to figure into the thought process!! :roll: I going to have a beer!!
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Post by KDXGarage »

Thanks for sharing the info, IC! Fortunately, KDX forks aren't super complicated, and I am going to play with those. The simpler, the better, well sorta. :grin:

I think I will go have one, too. Good idea!
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Post by Indawoods »

Buy a case and I'll join ya! :partyman:
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Post by skipro3 »

Jason: Thanks for the clairifications and tips. I've got more to study before I start messing with MY forks just yet.
Inda: "Golden Rule" That reminds me of a book called "Everything you need to know, you learn in kindergarten. Either folks are forgetting basic, good behavior, or they were never taught them to begin with.
IdahoCharley: You sandbagger!!! Sounds like you have more hands-on experiance with this kind of thing than the rest of us combined! How all the things you mentioned inter-realate makes me confused before I even get started, let alone on the 10th round of tweaking.
There's barely enough time for riding. When would I have time to teardown my forks over and over again, keep notes, and understand what I am doing and which direction I'm going in?
Man, I thought jetting a carb was tough. In retrospect, that's a piece-o-cake compared to tuning up a set of forks.
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Post by KDXGarage »

skipro3, how long has it been since you had the seals and / or bushings changed?

Typically, a Race Tech fork Gold Valve kit only comes with .1 mm and .15mm shims, so having only two different thickness shims may cut down on some of the confusion.
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Post by skipro3 »

Well, Jason, I had RT install the gold valves about a year ago, maybe less. At that time, they put new seals in and new springs as well. The old seals weren't leaking, but the tech recommended that, at $25, now would be a good time since there would not be additional labor charges. The old springs were too soft, being KX125 springs and my overloaded trunk. :oops:
I asked the tech to install new bushings but he told me the origonal ones were perfect and left them alone.

I probably have 8 or 9 hundred miles on them since then.
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Post by KDXGarage »

OK, cool. I have read that older bushings and / or seals can cause drag.
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Post by Indawoods »

Rebuild this next winter is going to be all new "Super Slick" components, Gold Valves and a shim stack designed by me... Yes.. I said me! :lol:

But I imagine I will play with the stacks throughout the riding season. I wish I had a big bag of shims to play with. There should be a place that sells them that way for us playaz...
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