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Discussion Starter · #1 ·
I ordered a seal kit from enduroforkseals.com for my Z1 RC2/ETA (the orange anniversary edition). I used a combination of several tutorials found on this site combined with Marzocchi's vague-ass-manuals to figure out how to tear into the fork.

So the teardown and assembly was pretty straight forward, the only thing I did was use FOX 7wt fork oil instead of Marzocchi 7.5 like it calls for. I was told at the LBS that not all fork oils follow a "standard weight" and I'd be just fine with FOX 7wt because it "runs a little heavy".

So here's my problem; today for the first ride on the newly sealed fork I bottom out on a drop that I've taken numerous times before. It sounded like a harsh "CLUNK" so I added a little more air then hiked up and did it again, ..."CLUNK" again, so I added even more air and turned the compression damping up a couple clicks. Finally no clunk but the fork is stiffer than it's ever been before and the rest of the ride totally sucked because it felt like a different fork.

I followed the Marz oil volume chart which, for my shock, says 135ml in the RT and 165ml in the LT.
What did I do wrong? Should I add more oil, and how much?
 

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If your fork bottoms out so easily then you'll probably put very little oil, but that sounds strange because Marzocchi's site oil levels are usually quite high. Make sure you put at least the recommended amount of oil that the chart recommends. (Maybe 140/170 if you're heavy).

The oil is a little heavier than the Mz original, so the oil weight is not the problem.

Are you sure you reasambled all properly??


By the way, when testing the oil setup try to avoid big jumps, because that CLUNK! is the stanchions hitting the inside of the lowers, and believe me, that's not good for your Z1 :D
 

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I can guarantee it's "slightly" low on oil.

I have no idea what the volume requirements are, as I've never really used them. I purge the carts and then add some more. The reason for purging first is obvious, then adding more serves the function of replacing "lost" oil that climbs for lubrication and replaces residual air bubbles in the carts and around the bushings.

Bottoming the fork hard is a sign of low oil if your sag is correct. If not, then set your sag up and see if it still bottoms. Additionally, my usual symptom of too low oil is after about 3-4 rides, I get harsh topout, for the reasons I named above. At the top of the cart, the piston passes through an air pocket and WHAM! slams to full extension and wreaks havoc on the lower arms.

PS- Check out my DIY writeup. I used a Z1 Light, but the Z1 Annivesary is 99% the same. The compression adjuster and bolt is slightly different (on closer inspection) on the 07, and there is no TAS cart, but it's 99% the same, as it pertains to the servicing.
 

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Discussion Starter · #4 ·
Jerk_Chicken said:
I can guarantee it's "slightly" low on oil.

I have no idea what the volume requirements are, as I've never really used them. I purge the carts and then add some more. The reason for purging first is obvious, then adding more serves the function of replacing "lost" oil that climbs for lubrication and replaces residual air bubbles in the carts and around the bushings.

Bottoming the fork hard is a sign of low oil if your sag is correct. If not, then set your sag up and see if it still bottoms. Additionally, my usual symptom of too low oil is after about 3-4 rides, I get harsh topout, for the reasons I named above. At the top of the cart, the piston passes through an air pocket and WHAM! slams to full extension and wreaks havoc on the lower arms.

PS- Check out my DIY writeup. I used a Z1 Light, but the Z1 Annivesary is 99% the same. The compression adjuster and bolt is slightly different (on closer inspection) on the 07, and there is no TAS cart, but it's 99% the same, as it pertains to the servicing.
Your write up is what I used as a step-by-step reference for the servicing (had my laptop out in the garage w/ me). I wouldn't have done it without that article since it's the most comprehensive one I've found; thanks for that!

As far as sag goes, I set it up exactly how it was before I took it apart. Again, the only way to eliminate bottoming was to "over" pressure the preload which created such a stiff fork that it was nearly unridable.

So let me get this straight as I think my re-assembly procedure might've been wrong. Should I have cycled the carts in the open bath of oil to assure they're filled? I was sure to cycle the old oil OUT of the carts. Is it possible that by just dropping them in and adding oil I've trapped air inside? My thinking was that the air would purge after the first few compression strokes.
You mentioned that you've never used oil "volume" as a measurement. What is your method? I've read on another thread that it's always better to measure oil "level"; but what is the level?
 

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Your assumption is quite likely. Your results may vary, but without cycling the carts, I was never able to get all the oil into the carts, sometimes noted by an improperly functioning ETA.

My method of adding the right amount of oil is to purge the carts, as mentioned, then add some more, usually about 10cc's. My method is trial and error, and then you can also get the idea of progressivity by adding more or less oil from there. As you reduce that air volume on both sides, you make the fork's spring curve deviate more from linear to more progressive. It's a superb feature, that while it requires trial and error, is bulletproof and does the job.
 

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Discussion Starter · #6 ·
Jerk_Chicken said:
Your assumption is quite likely. Your results may vary, but without cycling the carts, I was never able to get all the oil into the carts, sometimes noted by an improperly functioning ETA..
Amazing because I did notice something odd about the ETA the minute I hopped on it (may or maynot be related). When turning the knob to enable ETA it no longer "hard stops" at 1/4 turn. In other words, it will keep turning if I let it. The only thing stopping the knob is the little thumb tab contacting the crown. It still locks out but the adjuster is different; no bother since I never lock it out anyway, but still not right.

Jerk_Chicken said:
My method of adding the right amount of oil is to purge the carts, as mentioned, then add some more, usually about 10cc's. My method is trial and error, and then you can also get the idea of progressivity by adding more or less oil from there. As you reduce that air volume on both sides, you make the fork's spring curve deviate more from linear to more progressive. It's a superb feature, that while it requires trial and error, is bulletproof and does the job.
That makes sense and also explains the very linear feel I thought I was "imagining" :thumbsup:
Ahhh, this is all starting to come together for me, Thanks for your help so far!
 

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FlippinSweet said:
Amazing because I did notice something odd about the ETA the minute I hopped on it (may or maynot be related). When turning the knob to enable ETA it no longer "hard stops" at 1/4 turn. In other words, it will keep turning if I let it. The only thing stopping the knob is the little thumb tab contacting the crown. It still locks out but the adjuster is different; no bother since I never lock it out anyway, but still not right.

That makes sense and also explains the very linear feel I thought I was "imagining" :thumbsup:
Ahhh, this is all starting to come together for me, Thanks for your help so far!
You need to open the eta side, compress the fork a bit, then rotate it back. You'll see what I mean when you open it. The cart can be rotated to be in a select position. I think Zoke would deliver it so the tab was facing back and then locked towards 9 o clock. I start mine around 9, the rotate to 12.
 

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FWIW, I think the levels in millimeters from the top is supposed to be around 60 with the spring out and everything compressed.

As mentioned above you've got to make sure the carts are fully primed before you check that number. I usually cycle the fork and the rods for a while to get them full. To prime the ETA cart you've got to turn it on part way so you can feel some resistance when pulling up on the rod.
 

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.Danno. said:
FWIW, I think the levels in millimeters from the top is supposed to be around 60 with the spring out and everything compressed.

As mentioned above you've got to make sure the carts are fully primed before you check that number. I usually cycle the fork and the rods for a while to get them full. To prime the ETA cart you've got to turn it on part way so you can feel some resistance when pulling up on the rod.
Uh huh huh...you said "pulling on the rod"...huhuhuhuh
 

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Discussion Starter · #10 ·
.Danno. said:
FWIW, I think the levels in millimeters from the top is supposed to be around 60 with the spring out and everything compressed.
Two questions:
1)The oil volume chart gives two seperate volumes; 135ml/165ml RT/LT, I assume the 135ml volume is less to allow for oil displacement as you insert the spring, but with the spring out how do you measure 60mm on both sides? The 135ml side will a much lower level than the 160ml side wont it?

2) With everything compressed you mean top caps unscrewed and stancheons bottomed all the way down into the lowers or do I want to allow a "gap" like 1" or so? The reason I ask is because as I was adding the 160ml of oil to the one side it barely took it all. It filled all the way up to the threads on the top cap. In fact I even had to extend the stancheons a little to fit it all in there. So it was waaaay less than 60ml from the top.
 

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FlippinSweet said:
Two questions:
1)The oil volume chart gives two seperate volumes; 135ml/165ml RT/LT, I assume the 135ml volume is less to allow for oil displacement as you insert the spring, but with the spring out how do you measure 60mm on both sides? The 135ml side will a much lower level than the 160ml side wont it?

2) With everything compressed you mean top caps unscrewed and stancheons bottomed all the way down into the lowers or do I want to allow a "gap" like 1" or so? The reason I ask is because as I was adding the 160ml of oil to the one side it barely took it all. It filled all the way up to the threads on the top cap. In fact I even had to extend the stancheons a little to fit it all in there. So it was waaaay less than 60ml from the top.
Those are the number Marz gives. The trick is to have almost no air volume left when the fork is fully compressed. If the fork is completely topped out with oil when it's fully compressed it 'hydro locks" which feels like a bottom out, but not at full travel.

Since the spring takes up some volume the level on that side should probably be a little further down, but Marz has always given me the same level both sides whether it's a single or dual spring fork.

No gap when you make the measurement, fully compress the lowers. Make sure everything is primed though.

I sometimes check the sides individually to see how progressive each is and whether they have enough oil to prevent bottom out. To do that you put just one side at a time back together and see how hard it is to compress. Obviously the spring side will feel different, but I can tell a lot from the test.
 

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Discussion Starter · #13 · (Edited)
.Danno. said:
Those are the number Marz gives. The trick is to have almost no air volume left when the fork is fully compressed. If the fork is completely topped out with oil when it's fully compressed it 'hydro locks" which feels like a bottom out, but not at full travel.

Since the spring takes up some volume the level on that side should probably be a little further down, but Marz has always given me the same level both sides whether it's a single or dual spring fork.

No gap when you make the measurement, fully compress the lowers. Make sure everything is primed though.

I sometimes check the sides individually to see how progressive each is and whether they have enough oil to prevent bottom out. To do that you put just one side at a time back together and see how hard it is to compress. Obviously the spring side will feel different, but I can tell a lot from the test.
Okay, I fully understand where you're coming from but I'm really hung up on this oil "volume" crap that Marz recommends. Only for the simple fact that the volume that they recommend just does NOT add up! :madman:
They state: 135 / 165 (RL / LL respectively, 140 / 170 if you're over 176lbs). But with the fork fully compressed and both carts primed (yes I primed them very thoroughly this time) I can barely fit 165ml in the Left leg. It fills to the bottom of the threads of the top caps and I've still got 10 more cc's to go- and I haven't installed the spring yet.



The RL, with 135ml is right at 60mm from the top of the crown so based on your recommendation earlier I believe that side is correct. It's almost like there's a typo in the oil volume chart.

It's late so I'll pick this up again tomorrow after I get off work.

Thanks for everyone's help so far.
I've been photographing and documenting everything I've done so far. Hopefully I'll be able to put it all together and write up a few tips for the next n00b that decides to rebuild his/her fork.
 

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Danno,

One thing about checking the oil height and setting it is that it might not work for a lighter rider because that type of height can make it too progressive...and a small amount of oil can make a big difference at that limit. For a first time tuner, I would use your numbers as baseline (and I will as well for my next teardown of my gf's fork) and see where to go from there. She's especially difficult being 120 pounds, and in fact, I posted some time ago asking about a lighter spring. I think blackagness chimed in about going full air, something I'm a bit weary of, but it's yet another tuning option for these forks to pull the spring out completely and go full air.

Going back to the oil, my priority is getting the oil first at a height somewhere above where the oiling holes are for the carts, then to cycle them. As you suck oil up into them, the level in the bath drops. You never want that level to drop below the holes, perhaps including on an angle, otherwise you'll be sucking air, so it's good to have an idea of how far the holes are up in the leg. The main thing is you'll feel the air when you're at the top of travel.
 

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Jerk_Chicken said:
Danno,

One thing about checking the oil height and setting it is that it might not work for a lighter rider because that type of height can make it too progressive...and a small amount of oil can make a big difference at that limit. For a first time tuner, I would use your numbers as baseline (and I will as well for my next teardown of my gf's fork) and see where to go from there. She's especially difficult being 120 pounds, and in fact, I posted some time ago asking about a lighter spring. I think blackagness chimed in about going full air, something I'm a bit weary of, but it's yet another tuning option for these forks to pull the spring out completely and go full air.

Going back to the oil, my priority is getting the oil first at a height somewhere above where the oiling holes are for the carts, then to cycle them. As you suck oil up into them, the level in the bath drops. You never want that level to drop below the holes, perhaps including on an angle, otherwise you'll be sucking air, so it's good to have an idea of how far the holes are up in the leg. The main thing is you'll feel the air when you're at the top of travel.
I've always like level instead of volume because I can get it dialed right every change. I purposely run my forks with a little more than recommended levels for more progression. I know the exact point where they'll hydro lock and usually keep the level just low enough so that doesn't happen. If it does lock I know it because I blow oil past the seals. If you want it more linear run it 10mm lower.

BTW, I find it really, really, really, really, really hard to get the carts to complete empty. In one of those Marz tech threads Tom Rogers admitted the same and said those volumes on the Marz site are really more for production fills when the fork is dry. If those volumes are right for production odds are you'll overfill it when doing a change because the carts will still have oil in them.
 

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.Danno. said:
I've always like level instead of volume because I can get it dialed right every change.
Now if we can get a good chart by fill depth for all the forks, we'd be set. If a rider posted their depth difference by weight, it would even give a good starting point. I.E. set girlfriend's fork at -3mm below the chart setting. She weighs 120lbs...
 

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Discussion Starter · #17 ·
Jerk_Chicken said:
One thing about checking the oil height and setting it is that it might not work for a lighter rider because that type of height can make it too progressive...and a small amount of oil can make a big difference at that limit. For a first time tuner, I would use your numbers as baseline (and I will as well for my next teardown of my gf's fork) and see where to go from there.
FWIW I'm around 180 w/ gear. My ride style is light to med freeride. I like my fork with a tiny bit more than recommend sag yet remain very progressive especially for the occasional drop.

At this point, I'll be happy if I can just eliminate the harsh bottomout so if I use the -60mm as a base line you're saying it "might" make it too progressive?
In my mind too progressive = no harsh bottomout, no harsh bottomout = at least a rideable fork!

.Danno. said:
I've always like level instead of volume because I can get it dialed right every change. I purposely run my forks with a little more than recommended levels for more progression. I know the exact point where they'll hydro lock and usually keep the level just low enough so that doesn't happen. If it does lock I know it because I blow oil past the seals. If you want it more linear run it 10mm lower.
Okay, so if nothing else but on faith alone I think I'll toss the "volume" measurements out the window.

Danno, since you seem pretty confident with the -60mm method please tell me if I'm going about this right.
Since the RL is right at -60mm (fully compressed, carts primed) I'll leave that alone.
The LL, since the oil level is near the top of the threads (as in the image above), I'll remove some. With the spring out, fork compressed and carts primed, I'll draw oil out till i'm at the -60mm mark, install the spring and call it good.

Between your method and J/C's theory that those levels may make it too progressive I should be at a good starting point. I'll pedal my bike up the hill and hike that drop a couple times.

Question: If I bottom out which leg should I add more oil to? and how much? like 5cc's at a time?
 

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I don't want to override Danno on this. Since these forks require experience just in simple tuning, I would go with his method, then determine if you need to remove a few cc's of oil and from which or both sides. The trial and error at one point really makes the fork easier to tune later.

As far as emptying carts, of course you can't empty them fully and clean the interior, but you can certainly purge as much oil out as you can *. When I got my fork, the oil was awful, despite having been recently supposedly serviced. It was just wrong oil, wrong wrenching, etc. The fork and both carts independent of the fork were all sticky. This necessitated a purging and flushing. I used some cheap ATF in a container to create a bath and I just pumped the rods. You'll see sludge and metallic particles come out. No worries, just keep going. If you're really finicky, you can make a second purge in clean fluid. If you're regularly changing the oil once to twice a year, I see no need to go more than just purging out the cart and repriming it.

* the oil supply holes can squirt oil many feet, so be careful.
 

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Discussion Starter · #19 ·
So as per .Danno.'s technique I removed oil till I had -60mm level. Took it out today of the same drop that I've always taken. Fork still hard bottoms (*clank!*) but not quite as bad as when I first added oil.

So my question now is, do I add more oil at this point? And how much at a time, 10cc's? Which leg, or both?
 

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FlippinSweet said:
So as per .Danno.'s technique I removed oil till I had -60mm level. Took it out today of the same drop that I've always taken. Fork still hard bottoms (*clank!*) but not quite as bad as when I first added oil.

So my question now is, do I add more oil at this point? And how much at a time, 10cc's? Which leg, or both?
I'd try setting the levels at 50mm for both legs and try that. If the levels get high enough you'll hydro lock before you get full travel when you bottom out. Once you figure out the level that's right for you you'll be able to get it right every time you change the oil.

If you want to get the levels exactly right on each side you've got to check whether you can bottom out each side individually. I think I mentioned that in an earlier post. It's more work though.
 
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