[cjcrashesalot]

I just got a brand new 06 66sl today, and there is already something wrong.

The negative air chamber leaks air. It empties out from 75psi to 0psi in about 10 seconds.

This is just after inflating all of the chambers to a medium pressure (not coming close to exceeding any of the manufacturers limits), and riding it around the street a bit. I wanted to raise the travel back up, so I let all the air out of the negative chamber. When I went to fill it back up, it wouldn't hold air.

Anyone have/heard of this problem? Any suggestions?

This is really a pain...fortunately I can't really use that bike right now anyways so I'm not missing riding time.

 

[1soulrider]

Hate to have to state the obvious, but....call Marzocchi.

 

[boone]

call zoke and send it back!
Make them fix it, there have been enough problems with the 06
that they should take it back and fix it for you without question.

Boone

 

[allsk8sno]

yeah mine shipped with the main seal blown, oil all over the stanchion....be glad its not close to interbike...took them almost 2 months to get my fork back...and they forgot to put the little bottom out valve cover back on...

 

[kona-ryder]

Send it back to Zocchi. My bro had one sent out with a faulty cartridge, and it did the same thing the yours did. Not sure if its the same problem, but sounds pretty similar.

 

[vitox]

hi there

just wanted to point out some things about the design of that fork that might help you, maybe you dont have the problem you think you have, even,

first of all, the air valve in the RC2 side should be viewed as an air preload only, IE only useful for sag fine tuning AFTER you do the spring rate and rebound/comp adjustments.

secondly, the negative chamber in ATA forks is not accesible from the outside, if you are referring to the bottom chamber, that is the PAR chamber and works as a secondary (although i believe the volume is similar to the main chamber) positive chamber.
these two positive chambers are separated by a floating piston, so with this piston moving and changing the volume of the two chambers, you might encounter situations where the volume increases with the ATA adjustment and pressure might drop somewhat.

 

[boone]

let's make sure we are all talking about the same thing here!
06 66sl right?
If I remember correctly they did not have the ata feature yet.
Set up similar but not exactly the same thing.

.02
Booner

 

[vitox]

oops sorry

i was thinking about the 07 66sl1 ata!

 

[cjcrashesalot]

Thanks for all the help, turns out it was just a sticking valve. I messed around with it a bit, and it seems to be fine now.

Vitox- so the positive air on the rc2 side is only really for preload? Some of the Turner dudes on MTBR say to use it as a normal spring and inflate it to the same pressure as the other side...hmmm.

 

[mtbextremist]

Thanks for all the help, turns out it was just a sticking valve. I messed around with it a bit, and it seems to be fine now.

Vitox- so the positive air on the rc2 side is only really for preload? Some of the Turner dudes on MTBR say to use it as a normal spring and inflate it to the same pressure as the other side...hmmm.

I have had my 06 66sl apart before, and both sides are exactly the same thing "air preload." The Doppio side has more volume then the RC2 because it only uses 55ml of oil vs. the 200ml used in the RC2. All you do when you pump air into either side is add air pressure between the top cap and oil. No difference really... Now if you use twice the air in the Doppio Pos as in the RC2 positive or vice versa, you will achieve a bit different riding characteristics due to the higher pressure and larger volume. That is something you can tinker with yourself and see what you like. Personally, I keep both sides within 5psi of each other or equal. Currently I am running 25psi in the Doppio Pos,22psi in the Rc2 Pos, 100psi negative, 6psi par, 4 clicks of compression, and 3 clicks of rebound. That setup gives me 170mm of travel, and 2inches of sag. I weigh about 175 ibs ready to ride

 

[Kntr]

Air forks scare me.

 

[vitox]

Thanks for all the help, turns out it was just a sticking valve. I messed around with it a bit, and it seems to be fine now.

Vitox- so the positive air on the rc2 side is only really for preload? Some of the Turner dudes on MTBR say to use it as a normal spring and inflate it to the same pressure as the other side...hmmm.

oh hey hadnt seen this
what i posted further up was thinking you had the 07 air 66, yours is different altogether in that regard

on the doppio air you can use the RC2 side valve w/o preloading the fork because you can separately set negative pressure on the doppio air side, and just like the extremist says, you can fiddle a bit with the progression rates because the positive chambers have different volumes.

 

[cjcrashesalot]

Thanks for the info fellas

So then more air in the RC2 side (smaller volume) would make it more progressive, right?

I have ridden the fork only a little bit since I originally posted, so it still isn't broken in yet. But I'm having fun fiddling with it

 

[mtbextremist]

Thanks for the info fellas

So then more air in the RC2 side (smaller volume) would make it more progressive, right?

I have ridden the fork only a little bit since I originally posted, so it still isn't broken in yet. But I'm having fun fiddling with it

Yes that is correct. I havent tinkered with the difference between the chambers much. If you do some searching on MTBR, there is some VERY good information there to help you get it dialed. I believe TNC there said that it will run higher in its stroke and experience less brake dive with a slightly higher RC2 positive. Say 5-10 psi difference...

 

[gemini2k]

Air forks scare me.

i was was sessioning a 35x20 down (not lip to lip, but 20 feet down where i landed) foot road gap all weekend, landed almost into a nose manual on a rock one time, thing worked perfectly, btw, i'm 205 lbs.





But for some reason the ata would wind down about a full turn every run or so (down the whole course, not just the gap)

 

[allsk8sno]

cool on the progressiveness of the 2 main spring chambers, i am such a light wt i need to put 5wt oil in...but i am running compression all the way off, 20psi in each main and 100 or so negative, 15 par i think, i haven't bottomed it but i haven't hit anything over 6ft...i'll have to lower the pressures to get less brake dive, i definately get that pretty bad, feels slightly stictiony too but i guess its just teh extra seals required...and the oil change might help. now if i could just get my DHX 5 tuned right...

 

[JRogers]

cool on the progressiveness of the 2 main spring chambers, i am such a light wt i need to put 5wt oil in...but i am running compression all the way off, 20psi in each main and 100 or so negative, 15 par i think, i haven't bottomed it but i haven't hit anything over 6ft...i'll have to lower the pressures to get less brake dive, i definately get that pretty bad, feels slightly stictiony too but i guess its just teh extra seals required...and the oil change might help. now if i could just get my DHX 5 tuned right...

Brake dive and preload can be handled by the RC2 air chamber, but I think 20psi is way, way high and you will lose a lot of plushness that way. I have a 66sl and have been playing with the settings still, but, if it's like other marz forks, the air preload side should not be given much air. It is not just like another main spring- it functions differently and should be used for fine tuning and preload, not spring rate compensation. That's my feeling, anyway.

Anyone have a good way of stopping the ATA knob from turning while riding? Mine winds down quick. I think there are set screws on the cartridge, but are they a lasting solution.

Oh, and lock-tite the compression knob if you haven't already. Mine fell off in the first ride, as I forgot to do that.

 

[gemini2k]

Anyone have a good way of stopping the ATA knob from turning while riding? Mine winds down quick. I think there are set screws on the cartridge, but are they a lasting solution.

.

wUrd, im gonna try and get a hold of marzocchi tomorrow and find that out for myself, i'll let you know what they say.

 

[vitox]

Anyone have a good way of stopping the ATA knob from turning while riding? Mine winds down quick. I think there are set screws on the cartridge, but are they a lasting solution.

Oh, and lock-tite the compression knob if you haven't already. Mine fell off in the first ride, as I forgot to do that.

the ata travel loss is very easy to solve, just do this:
remove air chamber adjuster (the one you pull to get to the valve)
deflate RC2 side
undo ATA cartridge at the top (cassette lockring tool)
when you are about half done undoing the ata cart, you will see holes on opposing sides, inside that there are 2mm or 2,5mm allen detent screws, these preload the clicker ball for the ATA adjuster, just tighten these a bit, you can tighten them so hard you actually lock the adjuster and it wont move ever (not necessary), so just fiddle with that a little and it wont move anymore.

and as for your suspicion about the RC2 pressure, you are right, IMO preload from that side (talking about 07 forks here) should be kept under 10lbs so to not lose too much initial compliance.

 

[mtbextremist]

That is correct with the 07 models "but not with the 06" because the ATA cartridge will automatically adjust the negative pressure according to the positive. According to Boyles Law, presure is inversely propotional to the volume. So in the 06 model, when the fork is compressed, the volume of the main chambers decrease, and the pressure increases while the negative pressure decreases because its gaining volume. With the 07, as the fork is compressed the negative chamber will pick up some of that extra positive providing for a more linear/coil feel. So, when air is added to the RC2 side, the fork will gain a more progressive feel. It also is my understanding that the BO chamber on the 07 can actually be adjusted in size by the proportion of air in it vs in the negative. This way you can get a more controlled/consistent ramp up through more of the stroke rather than having it ramp up really quick at the end. I believe the 06 BO chamber is set. As said before, the only difference between the doppio and RC2 postive chambers in the 06 is the volume. There is not any equalization of POS and NEG going on.

 

[vitox]

extremist:

here is a diagram i of the ATA cartridge on a 66, i took a picture i found on mtbr and overlayed comments on it, it doesnt have the cartridge body (or air canister) but i drew it in there.
as you can see, the bottom out chamber is fixed due to the rope on the par chamber and the negative chamber is self adjusting to meet the positive pressure

 

[gemini2k]

and as for your suspicion about the RC2 pressure, you are right, IMO preload from that side (talking about 07 forks here) should be kept under 10lbs so to not lose too much initial compliance.

Whats the point of air preload on an air sprung fork. How are u supposed to get a pump in there anyways, unless im missing something, does the rebound adjust knob come off?

 

[vitox]

its the same as on a coil fork, for adjusting sag i suppose.

you flip up a little thingy, then undo the cap, and air it up, when the air cap is undone you can also remove the rebound adjuster, theyre concentric btw.

 

[Yeti]

so...vitox, if i make the par piston anchoring cables longer i m going to make the par chamber volume bigger, right? which is good to avoid so much progressivity.
if so, have you done this, or have you done anything at all to this system?

 

[mtbextremist]

extremist:

here is a diagram i of the ATA cartridge on a 66, i took a picture i found on mtbr and overlayed comments on it, it doesnt have the cartridge body (or air canister) but i drew it in there.
as you can see, the bottom out chamber is fixed due to the rope on the par chamber and the negative chamber is self adjusting to meet the positive pressure

Oh ok thanks Vitox. I always kina wanted to know what the inside of that cartridge looked like. On the older 07 66sl ATA forum "the HUGE one" on mtbr some guys were claiming that they could adjust the size of the par chamber. I suppose it could be possible that the cord that held the par cap in place could have broken? I kina wanna say I heard that was an early problem with the ata cartridge...but i could be wrong.
Im just sitting around waiting for my 06 66sl to get back from Marzocchi. Had them do the Works Package on it, so I am REALLY stoked expecially after riding my pile of $h!t 05 Dropoff Comp for 2 weeks! I HOPE it is gonna get here today. Supposedly they shipped it out last Monday or Tuesday....

 

[mtbextremist]

so...vitox, if i make the par piston anchoring cables longer i m going to make the par chamber volume bigger, right? which is good to avoid so much progressivity.
if so, have you done this, or have you done anything at all to this system?

Eh, I personally wouldnt play with that... You could EASILY get in over your head and screw something up. I would recomend staying out of the ATA Cartridge. Im sure you would need a special tool to crack er open. If you really feel the urge to dig in, I would defantely consult one of the Marzocchi Techs before doing anything in there. Oil change I can understand because it is as simple as unscrewing the top caps, flipping the fork up to drain the oil out, cycling the damping rod, and measuring the correct about oil back in. Modifying the internals could be a very bad call... Plus, the 66 sl ATA is supposed to be more coil like/linear compared to the 06 Model.