125-200cc RCI, Smart Performance, or Race Tech

I haven't worked on those particular KYB forks, so someone who has can definitely give more useful advice.

However, some simple things to consider to start:

-Remove some face shims from the BV
-Add a crossover between the face shims and the HSC taper
-Remove a face shim from the mid valve
-Add more mid valve float (via spacing out the piston or removing some of the shims from the front or rear of the stack)
-Remove some of the bleed stack (the 22.12 at the bottom of the BV) so that it opens sooner/easier

I am sure there is a ton of info out there about revalving a YZ for the woods, which would apply equally to your bike. For example: http://www.thumpertalk.com/topic/917535-yz125-2008-woods-fork-revalving/

If you take your fork apart and post the shims that are in there, I can make some halfass unprofessional recommendations, and if you're lucky the smarter guys here will come out of hiding too.

If your stack looks anything like the YZ stack, I'd pull a couple face shims, add a crossover, and take a face shim off the mid. Then ride it and go from there.

You guys are a huge help. I'll post up what I find when I open the cartridge. Gotta make sure I have the right tools... I do have a tusk kyb fork cap tool already.

One comment about SPI that might be unpopular (which is why I would share it here, but never on somewhere like TT):

Dave Johnson of SP is probably a smart guy. However, the way he and others talk about his suspension philosophies seems weird to me. From your thread on TT:

"We don't do normal "re-valves" but take more of an engineering approach to developing the circuits as to get them to do things that they were never originally designed to do."

"He's a legitimate engineer, like yourself, and has applied that training to dirt bike suspension as has no one else I can think of."

KYB and Showa have TEAMS of super smart guys working for them. I have a hard time taking a guy seriously who truly believes that suspension should work totally differently than the way these guys design it to. Unless the guy is like Nikoli Tesla, the odds that a rogue genius is ahead of two factories full of engineers seem small.

Second of all, Dave J is not the only engineer doing suspension. Guys like Jeremy Wilkey (MX-Tech) and Paul Thede are doing it too, for example. Hell, my local suspension tuner (Evan at Solid Performance) is a degreed engineer. I appreciate the more scientific approach to suspension that he is taking, but let's not act like he's a lone genius in a field of shade tree mechanics, it's not fair to the other guys.

So, maybe he has some cool ideas. I like some of his stuff. But comments like those above sort of irk me.

I feel the same way, I like the idea behind what he's saying, but when it comes to installing something on my bike, ehich I will be riding at over 50 mph, an landing from jumps 10 feet in the air, I feel more comfortable using a system that is proven. I ask for more clarification from them in the TT thread, but I honestly don't think its for me.

The Husky and YZ piston care the same KYB part number.

I bought an 08 YZ 125 from a guy who works at Marshall's Racing Suspension in Stillwater OK. This guy set the bike up for harescrambles with roots rocks and tight single track. I've serviced the forks and it appears that they used the stock internals and modified them for the woods.(no gold valves) I can tell you that these forks can be made to work very well, in fact every time I ride the 125 I get pissed at my Husky. If only I could get 250 power in that suspension. My advise is spend the money on the re-valve, pay the professionals to do their thing with your forks. You will likely spend more in time and fork oil than it's worth before you get the results of their experience.

Doug, 2 questions:

-Would you be willing to see what shim stack they put in the YZ? I'd be curious.

-If the YZ makes you hate your WR, why not get the WR set up the way you want it?

By the way, can anyone confirm spring rates in the 2012 CR125? I read it was 0.43 and 5.0. I think I can live with 0.43 in the forks, but 5.0 is light for the shock. I'll need 5.4-5.6, could get a titanium yz spring from a 450f. Race tech part numbers are the same, so it should work on the Sachs shock.

Good questions; if I figured out the shim stack by myself I wouldn't hesitate to share with the world however I don't feel right giving away someone else's hard earned knowledge. At one time I had many build secrets of my own on drag race car transmissions and alchohol fuel injection systems. I made my living off my knowledge so as a professional courtesy I wouldn't want to poach their knowledge. Most places charge about $200 for their knowledge and the rest is parts which I consider fair and money well spent.

As for my Husky I have the shock off of it now and later when the forks need servicing they will be sent off for revalve. The Husky is not horrible it just took riding my 125 to realize what I was missing.

Kyle, I would sell the entire bike or trade it for a trials bike or a 144 Husky.

I'm not an engineer but I knew that the Marzocchi 45s on my CR 125 needed help. In fact they needed to be reengineered and modified to do things that they were not designed to do! These forks had a lot of binding/stiction and not working properly due to some factory defects during assembly at the Marz factory. I'm not saying that Dave is smarter than the other tuners out there but he was willing to take on the challenge of making these forks works as best as they can, given the limits of old technology.

He did more than just a revalve. He kept costs down by modifying the stock piston. He eliminated almost all of the binding and setup the suspension to provide a wider margin of safety for the type of riding I do (vet mx). Not too many suspension tuners in my area (SF Bay Area) were willing to do much with the Marzocchi/Sachs combo on my Husky but Dave was willing to give it a shot and was committed to doing it right. Based on this alone, I will probably have him freshen up the suspension on my other Huskys with this fork/shock combo.

There's actually an equation you can use to roughly estimate the spring rate that you need based on the race sag of the current spring you have. Keep in mind that you need to be in the ball-park before trying to use this. You can't have 88mm race sag with 45mm static sag and try to use this equation. Using this equation, you can have more confidence in the racetech calculator, and you can choose the spring based on the sag you want. This does not work for progressive springs like the KTMs used to use (Husky springs are linear). For instance...

Race Sag is the measurement when you're sitting/standing on the bike - full gear
Static Sag is the measurement under the bike's own weight, without you sitting on it.
Both measurements are with respect to 'fully extended' measurement, when the bike is on the stand.

If:
Ro = Current Race Sag
Rt = Target Race Sag
So = Current Static Sag
St = Target Race Sag
Xo = Current Spring Rate
Xt = Estimated Target Spring Rate

Xt = Xo * (Ro - So) / (Rt - St)

So, for me, this is what the calculation suggests...

Xt = 5.0 kg/mm * (100-25) / (100-32)

Xt = 5.5 kg/mm Racetech suggests 5.5 for me and my style. etc.

This takes out some of the reliance on the racetech spring calculator. Just food for thought. I used it for my YZ last year and it worked out fairly well.

What sag do you get with the 5.4?