05-06 Marzocci valve specs
 

I happen to have two sets of forks appart today. An 05 DE200 and a 06 DE300. I found the Base valving is quite differant between the two years. The valves themselves are differant also as the 05 uses a 1mm bleed hole in the side of the port and the 06 uses a 2mm hole. Other notable differances is the 06 uses a bleed shim on the face with a 22mm shim that covers the ports. The 05 does not use a bleed shim but uses a smaller 21mm shim that does not cover the ports completely allowing some bleed. The cartridge, damper rod, bottoming cone and rebound valving is the same on both years. Only the base valves differ. Here are some pictures showing the differant shim stacks and differant size bleed hole in the base valves. Anyone have any imput on why the changes? Dave

I heard about them using the bleed shim. If you thought it was soft I guess you know why now. I assume that bleed hole in the base valve is the path for the comp adjuster?

I wonder if the Husky Zokes use the same base valve? I know they don't use a bleed shim. Even the heavier TE450 stays up in the travel nice without being harsh in the rocks.

What does the rebound/midvalve (checkplate?) look like?

The bleed hole is in the port that the oil flows through the shims. It appears to be a by pass for one port. The mid valve is a check plate . Dave

Wonder why the obsession with so much bleed?:confused:

Do you like the fork better than a WP, especially on the sharp edge (HSD) stuff?

Have any of you guys revalved your own 05 or 06 forks? What shims stacks did you use. There doesn't seem to be a lot of info on these forks anywhere so we might as well start a thread here. The first thing I am going to try is removing the 11 bleed shim on the face of the valve to see if this helps get rid of the mushy lack of feel these forks have. I don't know if this will make much differance with that big 2mm hole in the 06 port. Has anyone tried plugging the hole? Thanks, Dave

Pull the bleed shim and first crossover.

I am sooo happy to see KTMLew in this forum! Welcome! Thanks to this guy I have a great Ohlins fork... (and it wasn't at all great before...)

Putting a radius on the tubes to allow the upper bushing to float to prevent binding and prevent wearing the hard coating off the inside of the tubes was suggested by Terry Hay. Here is a picture of the tubes after I ground them. Not as pretty as turning them in a lathe but still gets the job done. Dave

It's amzing they STILL haven't fixed the bushing land?

valve specs
 

This is what l used on my 05 forks. 4 22x12, 14x10, 20x10, 18x10, 16x10, 14x10, 12x10 and 25x11

Is this bushing land issue unique to GasGas Zokes, or Huskys also? I ask because the Huskys I've ridden with LTR valving exibited NO bad habits. If anything, the overall bushing/tube fit seemed more relaxed, giving the fork very little stiction. I've had Husky Zokes apart but not that bushing, and didn't notice the fit.

I mentioned this to Les @ LTR - he revalves several sets of zokes a week, both husky and gasgas...

• He said he has never seen a clearance issue with this bushing; As a sidenote - He has seen wear associated with overtorqueing the triple clamp bolts, etc. (like any fork).
• He has seen four different compression pistons used over the last couple of years with varying amounts of bleed.
• What appears to look like a checkplate and spring can actually act as a mid-valve - depends on the tension of the spring.

jeff

Today I measured the thickness of the shims between the 05 and 06 and found they are differant also.

06 stk 05 stack
11x20
22x10 21x10 the 21mm face shim does not completely cover the ports on the 05 so there is some bleed.
11x20 11x10
19x10 19x10
17x10 17x10
11x10 11x10
16x10 16x15
16x10
15x15 15x15
14x15 14x20
14x15
13x20 13x20
12x20



Notice the 1st cross over is a thicker 11x20 in the 06 stack and the doubling up of the thinner 16x10 and 14x10 with the smaller 12x20 pivot. Keep in mind the 06 valve uses a 2mm bleed in one of the ports compared to a 1mm bleed in the 05. Anyone care to comment on what GasGas was thinking with the new specs? Dave

Pobit,
I think you should remove all shims in the 250 fork & replace them with
SAE 1/16" thick washers. It would give the other AA riders in District 23 a chance this summer. :D Paul sure is fast!
Bob

Dave, Terry also recommended it to mine marzocchies '99, as per the kayaba example. I never saw a kayaba inside, so i never really understood what Terry meant, but now seeing yr pictures i get it. You leave the middle part intact, and only bevel the sides to give room for the bushing to flex a little.

You felt it was worth the effort?

The only set of these i've had apart were the Cannondale version, so somewhere around a 2001/2003 model? The upper bushing was jammed into place when installed on the tube. On every other fork i've ever seen you can turn the bushing on the tube with very little effort. On these it was stuck solid. The bushing and land were basically the same exact width. No clearance for the bushing to move.

Just measured a 89 RM 46mm fork tube as it was handy.

Bushing width measures 19.79mm--Bushing land 20.09 = clearance of .30mm or .012" this allows the bushing to float some and not get bound up.

Land dia at center 44.90. Center area is 16.59mm wide--At edges dia is 44.69= .31mm/.012" of clearance for the bushing to rock on the tube. Reduced dia area is about 1.50mm wide per side.

I can take pictures if it will help anyone.

I already had the forks apart to replace the seals so it wasn't much effort to grind the tubes with a Dremel. I did two sets of forks, both with 1 year of riding time and the coating on the upper tubes looked like new on both forks. I have noticed the forks bind under a load and hopefully this will solve some of that. Dave

:) Very nice elaborations on this subject, Lew. Now i finally see what Terry meant with the upper bushing problem.
Although i can see the picture now ;) I surely like to see some pictures. I feel that more people wld appreciate that.

Dave, when do you plan on yr test ride? Hopefully soon?!
Ohh, and how did you find out about the bind up. Riding with a ty-strap around the fork and hitting that brick several times?

Dave, again... how wld i investigate binding with my marzocchies? Is it something you learn by experience or is there a trick that can address binding?
I am very light on mine compressions valving, midvalve aswell bottomvalve, but still i feel some spike on 2" roots.
Is this reshaping of the land of the bushes helping me in this situation?

I once ridden this showa Honda fork... i never felt any spike.....
This is what i like to accomplish with mine marzochies;)

Ok, here a report about the marzocchies 45mm.
First i disassembled the forks completely and went step by step to measure and look at the various parts.
One upper bushing was very thight on its land. The other was so so.
With the outer legs in the triple clamps i cld feel some binding at the last part of travel. This is the upper clamp area.
Both legs have a freebleed hole in the legs at 17cm of the upper bushing. So i felt no need for extra holes at 20cm.
I started working.
I did the bushing land as per Pobit pictures. Now both bushing have some room to flex and turn on the land.
With everything assembled this gave some free play(more than was before offcourse). I checked binding by putting the outer legs in the triple clamps, torqued the bolts to specs and when shoving the inner legs tru felt no binding at all at the triple clamp area. What i did notice was quite some drag/binding caused by the seals. I sure feel that slippery oil will benefit some forks with thight seals.
Today i went for a little ride, and first thing i noticed was that with slap down landing of the front forks(you get these with ending a wheely) there is a softer cushion. I address this to the more free play of the bushings. Correct me if i am wrong in my thinking.
I surely felt the whole travel was more compliant, but i did not do a real high speed spike test. I also felt that the rebound was better?! The fork was less dribbling over smaller impacts, at speed. And i had even less rebound than before.
I did nothing to my valving, so the only thing i did was the bushing land.
What i did do was running less oil volume than ever before. Terry Hay gave me his advice to run oil height of 130mm, where i normally use around 90mm. I use ATF II type, which shld read 7,5 sae of forkoil.
Well, so far my experience with the year 99 marzochies and i feel that everyone can benefit as they are not changed for over 8 years now. Maybe the valves are a little different but all dimensions are still the same.
I have a very light midvalve, with around 1.0mm of lift, and a very light basevalve. Rebound is rather heavy simmed since it is such a small cartridge.
Because of the small cartridge the basevalve sees rather much oil.
Maybe my midvalve is too light but i rather have no spike with an occasionally bottom out than otherwise.
When i did some more riding i will report back.

I'm assuming everyone knows the numbers in my other post won't match the Zoch's? They are just for reference. An X wide bushing on a Jap bike tube has Y clearance.

:)

Ktmlew, Pobit, and Terry Hay, your guys experience really opened my eyes regarding the need of clearence at these bushings.
It is funny though, that a fork can be too rigid. :)

I need to defer all credit to Terry Hay. He pointed it out and I just looked at the Cannodale forks to see if the problem still existed. Yep!:rolleyes:

I don't want to get into a battle - but based on what I understand there is nothing wrong with this fork that needs to be "fixed".

What matters is the clearance between the bushing and the fork upper - and on some forks it does make sense to relieve the "land" in order to increase this clearance (race-tech does this on certain showa forks). The marzocchi fork has more than sufficient clearance in this area and no modification is necessary to "fix it".

jeff

p.s. The only reason I am saying something here is that I don't feel that there is anything wrong with this fork in this area - when properly valved the fork is very, very supple - even with very little break in time on them.

IMO these have EXACTLY the same problem as the old Showas.

The Marzocchi Shiver fork I had apart had ZERO clearance for the bushing to move ON the tube. Seems to me that would create a "scraper" type situation? Could be why they tend to foul the oil quickly? Whether you "fix" the bushing land or hone the upper tube, you are re-engineering a poor design. I wouldn't want to take the chance of cutting thru any hard-coated anodizing in the upper tube though.

If these don't suffer from binding why do they have to be valved so soft?

Not trying to argue just have an entirely different opinion of what I've seen.

Well, if it is an issue its certainly not consistant and/or widespread. The Huskys I've ridden were exceptional in their lack of stiction, and the local KTM/GG/Husky dealer has been very happy with the forks, eaisly prefering them to the WPs.

The forks I looked at were 2002/2003? models and I think they made some serious attempts to correct some problems with the 04 models. So this may well NOT be a concern for the later models forks!!! :cool:

I corrected my previous post as I meant to say "binding" when I posted stiction. Two different things...

I'm really curious to see the later model fork apart to see if they "fixed" the bushing land.

These forks do not have the same problem as the showas - the showas didn't have enough clearance between the bushing and the upper fork leg. You are stating that having the bushing fit tight on the lower leg is an issue - given the choice of having it fit snug and having it "float" - I would prefer to have it fit snug; Having it fit snug doesn't turn it into a "scraper" as you suggest.

The other comments you make about the fork are not consistent with what I know about this fork; I confirmed this with a suspension tuner who has done over a hundred sets of these forks...

1. This fork does not have to be "valved so soft" to compensate for "binding". They are valved like any other "good working" fork.

2. These forks do not "foul the oil" quickly when installed properly. There will be dirty oil if the triple clamp pinch bolts are improperly torqued to a high value; The causes the upper fork tube to collapse and the fork to bind, and wear, when the slider passes this area.

Both a friend (the suspension tuner friend of mine) and I have cannondale marzocchi forks mounted on a different bike - valved for my weight and terrain and they are "pure magic". My friend has had both sets apart and there is absolutely nothing wrong with them.

Again, I don't want to battle. And the only reason I am saying anything is that the fork is being unfairly characterized. And both the fork and the bike are being improperly demeaned as a result.

jeff

Again, we will have to disagree. :cool:

Well, at least we can agree on that! ;)

Frankly, I don't understand the logic that you are applying. And, given that there is nothing wrong with the fork, "fixing something that ain't broke" will do more harm than good.

jeff

My take on this:

I understand the logic, just not sure it exists. I beleive that KTMLew's reasoning is that the fork outer tube will always be slightly compresed, regardless of T clamp torque, and there must be some bushing play to account for it. Well, theoretically this could be done in two ways: static clearance, with the bushing fixed to the inner tube, or dynamic clearance between the bushing ID and land OD, where the bushing is allowed to compress slightly, like a piston ring. Valid point, but whos to say the static clearance is inadequate? Any data? Bore mic the fork outer along its length and lets see the effect of T clamp bolt torque. It would be interesting.

Also, I think most people overtorque their T clamps, and some listed specs are too high. I clean the fork tubes and clamp bores and go no more than 15 -16 Nm.

When I had the Husky Zokes apart, The first thing I noticed is how "loose" they felt compared to my sticky WPs. Not in a bad way, but a good stiction free way. This, and excellent performance, would seem to point to adequate clearance. You would think if this was a widespread problem, all the big tuners here would be on the bandwagon machining fork tubes for additional $$, especially now, since Husky sales have exploded.

Besides some anticipated valving changes(like I always need for rocks) I'm looking forward to riding the '07 Zoke fork.

GMP

Not to beat a dead horse but...I have only had the 02-03 fork apart and inspected the bushings fit on the tube. The bushing snap fits and you can NOT turn it on the tube. Zero end-clearance. Only forks I've ever seen with this build. Fixed position = binding when the upper tube flexes. Don't see any reason you couldn't just narrow the bushing slightly to allow it to float some but that still doesn't address the bushings need to be able to "rock" slightly when needed. It's not something you can feel when cycling the forks without a sufficient load to flex the outer tube.

I look at things strictly from an engineering viewpoint. Couldn't care less who built the product. Didn't come here to bash, just trying to relay the info I have SEEN with my own eyes not what someone else told me. NOT opinion, facts. Bushing fits too tight on tube...

As I said before, it's my understanding they tried to address some issues around 04 but I don't know if this is one of them?

Hi Lew,
As a sidenote, GMP and I are both very well qualified engineers as well...

You have stated as fact that the bushing being tight on the land will cause binding in this fork. This is not fact; It is your opinion and is not supported by reported experiences with this fork. (e.g. it is very plush when revalved and not spikey in any way, shape or form).

By the way, I spoke to Les at LTR and he said nearly all the marzocchi forks he sees have this bushing fitting tight, but that's it not an issue on this fork due to this fork having more than sufficient overlap. (He services and revalves 5-10 sets of marzocchis every week and has been doing so for the last several years...)

I have personal experience with 5 sets of the marzocchi shiver fork - three of them are cannondale surplus stock. The ones on my XR have tight fitting bushings and I am amazed at how good they are, even with very little break in time on them. I am an A rider with 35 years of riding experience and I ride very aggressively through roots, rocks and whoops; I can confidently say that if they had any issue - I would feel it...

This is kind of like a guy going into a doctor's office for their annual checkup and having the physician tell him that his knee has an issue that is causing severe pain; Performing a knee-ectomy will resolve the issue. Given that we are all human - some folks would immediately feel this pain and request to have their knee hacked off. Hopefully, a large percentage would say "my knee doesn't hurt" and spend the rest of their day looking for a new doctor... :)


jeff

I disagree. Period. It's NOT "my opinion" if Les also says the bushing is "fixed" that would make it a fact, right?

We will just have to disagree on this one! ;)

Nice try...

Wrong. You have stated that it is a fact that having low clearance on this bushing causes the fork to bind. This is not "fact"; This is your opinion. The marzocchi shiver fork's excellent behavior in the field would not lead a reasonable person to believe that this opinion is valid.

I do agree with this statement.

jeff

Why are the bushing lands of other forks made with more freeplay? Maybe there is a need for it?

Hi pobit, thanks for this very interesting post and pictures.

I did post your pictures at a forum at thumpertalk.com, hope you don’t mind? A guy claims the suspension of his ’07 Husky WR250 is very different from his ’04 WR250, so maybe the ’07 husky has this new valving. I did mention where I got the pictures from of course.

I have a question. Am I pointing at the “mid-valve” in the picture?

http://gulli.internet.is/ymislegt/quiz_midvalve.GIF

#36 is the rebound/mid-valve piston. The upper side is the "mid-valve" but in this picture it would just be a check-plate set-up. #33 is the check-spring and #34 is the check-plate. If it had mutiple shims of different dia's it would then be consdiered a mid-valve. #37 is the rebound stack.