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Te mortuo heres tibi sim?
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Discussion Starter · #1 ·
Thoughts anyone?

My 66 ATA is having a decently loud "click" upon rebound topout. Doesn't matter if it's from a little hit, big hit, me bouncing around on the bike, rebound/compression adjustments played with throughout their ranges.
Quick and dirty impression is nothing is wrong, but thought I'd ask a bit here before tearing into the fork/calling Marzocchi to just ask for either a new fork or refunded money.

No noise when compressing. Fork feels fine, just annoying sounding. Can't help but wonder if something is actually wrong/going to break. I'm leery of riding the damn thing at this point. I've not noticed a change in it's performance since fixing the other problems I was having, it's just making a click noise.

1. QR axle loosening-->fatter o-ring has stopped that. Been beating on it for a bit since then, and no sign of loosening.

2. ATA/PAR chambers leaking/equalizing pressure-->removed the IFP so now the air spring side is just one freaking big air chamber. Added ~20ml oil to the bottom of the air chamber to take up the volume lost from the IFP.

3. Preload side air port leaks. Useless. No biggy since I'm liking the fork now just running 40-45psi in the (now) one main air chamber.

I don't really need or use the ATA feature anyhow, so more and more I'm wishing I'd bought a Totem Solo Air, as I loooooove the Lyric Solo Air on my hardtail. :madman:
 

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Try putting your hand over the ata top cap an feel to see if there is a very slight vertical play on the shaft of the ata and the top cap as you compress and extend the fork , sometimes there is and this is a common source of that noise.
 

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Te mortuo heres tibi sim?
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Discussion Starter · #4 · (Edited)
bear said:
You do know that the valve in the air port is the probable leak cause, that it's a standard schreader valve like used in pretty much every tire valve and non-presta tube on the planet, and pretty dang cheap to get replacements for. :^)
Yeah, I know. Not worried about that just yet, since I'm not using the preload air at this point. I can get it to not leak too, it's just that it's a pain in the ass.

Add it to the list of things I shouldn't have to deal with on a still fairly new-ish fork.

Edit: to add an aside, the ATA and PAR carts are not leaking out to the fork leg, just equalizing pressure/leaking between the two chambers/carts/whatever.
 

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Sounds like we are competing for the most issues...I think its a tie. 1 - stuck down and broken rebound; 2 - leaking seals between chambers; 3 - top out clunk; 4 - new crown and steerer.

(See my issue #3...sounds similar) I had a top out clunk very similar to what you are describing and the fix was to replace the ATA nob with a new one from Marz that has to be slightly lifted to turn. When pushed down the new knob locks in place. Basically, my ATA knob would move about an 1/8 and 1/4 of a turn. Not a enough to adjust the travel, but basically within the range of a single click. This small amount of play caused a top out clunk that a rider next to me could hear and I could feel. The new knob fixed the problem and was sent to me by Marz (this was the one time I did not have to send the fork in).

I also added some oil to the rebound side....low oil can cause a top out clunk also but in hind sight this was not needed for my fork.

I only have two rides on the fork since the new crown, but it has been quite and performed well...imagine that. :rolleyes: (Although both rides have ended short with other mechanical issues...flats; leaking spares; binding chains. :confused: )

(The bike is now on its way to Deer Valley for a week of downhill riding in early July...this will be the real test)
 

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i used to have air bleed between par and sfa of late, but then when three rides after my last oil/seal change the par cable (new one direct from Tom at zoke) disintegrated on one side I just took the piston out.

i'm unsure whether i have a new issue developing with the fork or not, we'll see, as in air leak from SFA to fork leg. I won't be happy if so, because that'll require at least sending in the ATA cart (I'd much prefer just talking zoke into selling me one) or the whole fork (unacceptable).

We shall see, how it goes, been holding nicely this week (three rides so far totalling about 70 miles of trail) but the weekend riding should tell.

I have *really* liked how this fork works (07 66 SL1 ATA) for me on my bike, and with over 3k miles on it since it went on the bike in May/June '07 I can't really complain about it needing reasonable service work.

I just wish I could afford to have a spare around.
 

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Te mortuo heres tibi sim?
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Discussion Starter · #7 ·
Called Marzocchi and:

Tracked it down to: it's the damper side. Click noise only occurs when running any air in the damper side preload system.

It's one of two things:

1. There is a small spring inside the upper part of the damper shaft that can pop one end free a bit and make noise. Tried doing what the tech suggested to re-seat it, with no change.

2. The damper shaft/topcap interface is not as snug as it should be. Says to shim it slightly where the two bits interface. Haven't tried that yet; on tap for later this evening/tomorrow morning.

The fork feels very good running all air pressure on the spring side, and none on the preload side. However, with a couple PSI on the preload side, I can run drastically lower pressure on the spring side. I'd rather do that; figure it's better for long term durabilty. If the two fixes don't work, I either live with the click, or all air on the one side run at higher pressure. Either way, they feel it's not any sort of warrantee issue.

According to the tech, no harm done to the fork without the IFP, or running that side with full air in one massive cartridge, or if the two chambers are used, no harm done if the equalize pressure, or don't have the 30PSI differential that Marzocch suggest - they just say it won't work as well as they'd like.
 
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