AM-1 Problem and Questions- Mtbr.com
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  1. #1
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    AM-1 Problem and Questions

    My AM-1 has begun clanking again on compression and seems more harsh. As noted by others below, this suggests that air needs to be bled from the TST cartridge. If this is true, this would be the second time this is required of my fork. How does this occur? The fork very suddenly began doing it, as it seemed normal yesterday and began clanking/harshness today on Noble. Can the TST cartridge suddenly take on more air? I was under the impression that this was something set at the factory rather than something that was variable. If anyone can explain, please do. Ownership of this fork has thus far seriously weakened my impression of Marzocchi's reliability, though their customer service has been good.

  2. #2
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    Air can enter through the shaft seal or a leaking bladder. I have one and am waiting for mine to crap out. Its supposed to be air free. When mine goes bad, back to the ssv damper fork I go...

  3. #3

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    I have the same fork and it does the same thing,what kind of crack is that, i want to send mine in after i get my pike.Get it fixed up so it can find a home on the mtbr classifeds.

  4. #4
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    me too! my am1 has the same problem and it's driving me nuts! i hate marzocchi!!

  5. #5
    MK_
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    Sounds like all of you ought to contact Marzocchi and let them replace the damper. They might be kind enough to send one to you and you send yours back to them. This is no reason to hate Marzocchi as the AM1 is one of a handful of very well damped forks. Don't give up on it, and you would be fools to go back to SSV and call it a day.

    _MK

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  6. #6
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    Mine had sucked in air during the first few months for some reason. I don't know why, but I decided to "bleed" the air out, and this involved unscrewing the cartridge and letting the air and some of the oil out, and then it worked much better. There are service instructions for the proper amount of oil in the cartridge, but I don't have any problems with it, and it's been about 8-10 months since I did that, and it's been running fine. I replaced the oil with 5wt about a month ago and I think that helped as well, it did feel pretty crappy when it had all the air in there, even when I let all of the air out, there was air trapped under the bladder and I couldn't get it to work because the bladder was so expanded that it was "pinching" the stanchions at about half compression. So, servicing the cartridge made a huge improvement.

    That said, my Z150 HSCV cartridge with top-cap should be here tomorrow.
    "It's only when you stand over it, you know, when you physically stand over the bike, that then you say 'hey, I don't have much stand over height', you know"-T. Ellsworth

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  7. #7
    Slowest Rider
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    Quote Originally Posted by Jayem
    Mine had sucked in air during the first few months for some reason.... the bladder was so expanded that it was "pinching" the stanchions at about half compression.
    Did this reduce the travel of your fork?

    When I had my AM1 serviced a few months ago, the ETA stopped holding down right. There was a thread with a big discussion about how much oil was needed in the left TAS side to make it work right, with the final answer being around 130-140 ml (in spite of Marz's web site saying 175+). More than that and the fork wouldn't get full travel, and less than that and the ETA wouldn't hold. But even now, I don't seem to get the travel the whole way. With all my big weight jumping very hard on the fork in the DS setting, I can only go down 110 mm out of 140 travel. That's all my tie wrap shows on the trail too. I seem to remember going down most all the way when it was new. The fork doesn't seem to be reacting quite as well either, but I'm not an expert enough to know really.

    I'm now wondering if something happened to the TST cartridge side, which was also serviced at the same time. I do get some sort of subtle rattle or clunking out of the front fork on occasions. Since servicing, I've had to reduce the air pressure in the TST from 55 to 45 psi and it still seems stiff. I need to use the soft DS setting all the time now. But I figured my loosing 40 lbs (from 270 to 230) may also have had something to do with it.

    Do any of these symptoms sound like similar to the TST air trappment you describe?
    It's not slow, it's doing more MTB time.

  8. #8
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    That sounds like it might be a mechanical problem, although I couldn't get my fork to be "plush" with the air-pocket that was trapped beneath the damping cartridge. I could barely get the catridge out without damaging the bladder due to it being "overpressurized". I don't think it was keeping me from getting full travel, it did make the fork more "progressive" though, but the biggest effect was that it made it much harsher. Some travel loss would be expected, but your example sounds pretty extreme.

    I'd be able to tell pretty fast by unscrewing the top cap of your fork and looking at the bladder.
    "It's only when you stand over it, you know, when you physically stand over the bike, that then you say 'hey, I don't have much stand over height', you know"-T. Ellsworth

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  9. #9
    MK_
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    Quote Originally Posted by BigLarry
    Did this reduce the travel of your fork?

    When I had my AM1 serviced a few months ago, the ETA stopped holding down right. There was a thread with a big discussion about how much oil was needed in the left TAS side to make it work right, with the final answer being around 130-140 ml (in spite of Marz's web site saying 175+). More than that and the fork wouldn't get full travel, and less than that and the ETA wouldn't hold. But even now, I don't seem to get the travel the whole way. With all my big weight jumping very hard on the fork in the DS setting, I can only go down 110 mm out of 140 travel. That's all my tie wrap shows on the trail too. I seem to remember going down most all the way when it was new. The fork doesn't seem to be reacting quite as well either, but I'm not an expert enough to know really.

    I'm now wondering if something happened to the TST cartridge side, which was also serviced at the same time. I do get some sort of subtle rattle or clunking out of the front fork on occasions. Since servicing, I've had to reduce the air pressure in the TST from 55 to 45 psi and it still seems stiff. I need to use the soft DS setting all the time now. But I figured my loosing 40 lbs (from 270 to 230) may also have had something to do with it.

    Do any of these symptoms sound like similar to the TST air trappment you describe?
    How much oil do you have on the TST side? Too much oil there limits travel as well.

    _MK

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  10. #10
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    Quote Originally Posted by MK_
    How much oil do you have on the TST side? Too much oil there limits travel as well.

    _MK
    The right amount, I think?

    My LBS did the repair, and they're Marz experts with close ties to the Marz techs. For example, they told me up front about the fork needing 130 cc of oil in the TAS side. But it took me a couple iterations like me having them setting the fork with the 175 cc spec on Marz web site only to find less than half travel, just like they warned.

    However, they weren't familiar with AM1's new TST rework at the time, but one of Marz techs personally trained them at a race booth, as they said that side was a bit tricky.

    Quote Originally Posted by Jayem
    I'd be able to tell pretty fast by unscrewing the top cap of your fork and looking at the bladder.
    How do I check? I heard somewhere I needed a special thin wall nut driver to remove the screw under the cap . Is that right? What do I look for, a bladder pressing against the inner wall? Where did you get the service instructions?
    It's not slow, it's doing more MTB time.

  11. #11
    MK_
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    Quote Originally Posted by BigLarry
    The right amount, I think?

    My LBS did the repair, and they're Marz experts with close ties to the Marz techs. For example, they told me up front about the fork needing 130 cc of oil in the TAS side. But it took me a couple iterations like me having them setting the fork with the 175 cc spec on Marz web site only to find less than half travel, just like they warned.

    However, they weren't familiar with AM1's new TST rework at the time, but one of Marz techs personally trained them at a race booth, as they said that side was a bit tricky.
    TST side requires 40-45cc of oil. The fork comes apart just about as easily as a Z1 with addition of having to remove the two knobs from the bottom. Not sure how to check. Maybe unscrew the ETA side top cap and compress the fork, see if you can get it all the way to the bottom.

    _MK

    "The things you get fired for when you’re young are the same things you get Lifetime Achievements for when you’re old."

  12. #12
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    Quote Originally Posted by BigLarry
    The right amount, I think?

    My LBS did the repair, and they're Marz experts with close ties to the Marz techs. For example, they told me up front about the fork needing 130 cc of oil in the TAS side. But it took me a couple iterations like me having them setting the fork with the 175 cc spec on Marz web site only to find less than half travel, just like they warned.

    However, they weren't familiar with AM1's new TST rework at the time, but one of Marz techs personally trained them at a race booth, as they said that side was a bit tricky.


    How do I check? I heard somewhere I needed a special thin wall nut driver to remove the screw under the cap . Is that right? What do I look for, a bladder pressing against the inner wall? Where did you get the service instructions?
    130mm in the TAS side is a little too low also. I have found that 140ml is optimal. I know you said that the shop folk are "experts" but did they bleed the entire cartridge before adding the fluid back to the TAS side? Too much oil over there will definately limit travel.

    It's an easy fix. Take off the adj knobs (watch out for that spring and detent rod under the TST side)

    Unscrew the damper top caps (I think it is a 21mm) nothing special needed.

    Push the stanchions down and dump out the oil.

    Cycle the TAS cart to get all the oil out of it. May take several times to completely empty it.

    Refill with a good 125/150 fluid (I like the Maxima stuff - cheap too) 140ml TAS / 40ML TST and button it back up.

    Enjoy!

  13. #13
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    Quote Originally Posted by SSINGA
    130mm in the TAS side is a little too low also. I have found that 140ml is optimal. I know you said that the shop folk are "experts" but did they bleed the entire cartridge before adding the fluid back to the TAS side? Too much oil over there will definately limit travel.
    They said they indeed removed all oil and cartridges before bleeding. They also will not "add" say 10 ml to get from 130 to 140. They say the only precise way is to dump it all, with cycling to get every drop out, and insert the exact amount from a calibrated syringe-type pump they showed me. (I'll need to get one of those too.) They said it could be a few ml over 130 cc. They initially told me it was 140, but weeks later admitted they'd actually reduced the last working fill closer to 130 ml that they felt confident was correct, but told me it was 140 ml just to satisfy my demand. The ETA held down so I'm happy just the same. I just want to figure out what happened to the last 25+ mm of bottom travel.

    Thanks for the advice. I'll have to get some fill tubes and oil, funnels, etc. and start playing around. This week may be good with the bad weather.

    Another mystery is why my TST needs such little air pressure compared to Marz's charts, less than 40 ps for my 230 lbs, versus 60+ on Marz's manual. It could be Marzocchi's manuals and charts are screwed up as usual - many others have also noted a much lower TST pressure for their weight. Or it could be this TST has the wrong oil level or trapped air as mentioned. Either way, it means I should "experiment" with the fork and different oil levels.

    I'm also wondering if Marzocchi specifies their higher oil and pressure levels to make a stiff fork to handle the worst case big hits (say 4-5' drops), and many are just making it plusher because the fork works better that way in the XC mode with never a drop over 2 feet that many including me tend to do.
    It's not slow, it's doing more MTB time.

  14. #14

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    big larry

    I'm from San Jose Big Larry,and I have the same fork,did you take it to trail head?

  15. #15
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    Quote Originally Posted by spongstick
    I'm from San Jose Big Larry,and I have the same fork,did you take it to trail head?
    No, I've been using Reed's, the Heckler dealer. Jesse there seems to know Marz forks extremely well. Still, I've been tempted to try Trail Head for a good second opinion, but they've got a 3 to 4 week back log each time I ask.
    It's not slow, it's doing more MTB time.

  16. #16
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    Hi,
    I started a new thread on the AM1 problem I am having but thought it might help to post it here also.

    I have a 05 AM1 that lost all air pressure ( 0 lbs on guage ) during a ride on Saturday. When I got home I put 70 lbs of pressure in it. I let the bike sit overnight and rechecked it in the morning and pressure was 70 lbs exactly. Cool right, well not exactly. 10 minutes into the ride this morning shock was bottomed out again and air pressure at 0.

    Conditions both days was cold at about 25 degrees F. Muddy/wet/icy on Sat and snow on Sunday. Both were slow rides because of the conditions.

    Has anyone else had or know about a common problem with this fork? Already needed to send fork back for warranty issue with loose stanchion bushings ( 4 weeks ) and I don't want to send it back to Marzocchi AGAIN unless I really need to.

    Thanks

    dawgboy

  17. #17
    MK_
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    Quote Originally Posted by dawgboy
    Conditions both days was cold at about 25 degrees F. Muddy/wet/icy on Sat and snow on Sunday. Both were slow rides because of the conditions.
    While I haven't seen any reports of Marzocchi seals not holding air at low temperatures, the issues in not at all uncommon, particularly with Fox rear shocks. The fact that the fork held air at your house, where it is warm, and lost it on trail, where it was cold, points in the direction of the seals shrinking enough at low temps to let air past. I would contact Marzocchi and get them to send you a new set of seals or get a set from Enduro.

    _MK

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  18. #18
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    I ride in conditions like that all the time with no problem, in fact on yesterday's ride it was at or below freezing the entire time where I was riding. I'd say the problem may be "ride" related, as the bike starts moving and the fork starts cycling, something is going wrong. I'd check all the seals, take the top-cap apart, and inspect.

    I'm running an ZAM150 now, that is an AM1 that has been fitted with Z1 lowers, and fitted now with a Z150 damping catridge. It still uses air preload though, but Marzocchi sent me the wrong top-cap for the fork. To fix the problem and make it ridable, I used some extra parts that I had since they sent me the wrong top-cap, and made a "plug" so the air would not escape. Due to the way it all threads together, I'm missing out on about 5-8mm of travel right now, but it's good enough to suffice untill I get the correct top cap.

    After making this thing work though, I have a pretty good idea of how the fork holds air in it. Either the valve core (where you put air into the leg) is malfunctioning, or it's likely one of 3 seals, one on the foot nut (it would be leaking oil if this was compramised), one on the top cap itself (this wouldn't allow air to escape very fast, probably not this one) or the seal that is around the adjuster that pokes through the top cap, and I'd say there's a higher chance that this is the one that is compramised, or the valve core.
    "It's only when you stand over it, you know, when you physically stand over the bike, that then you say 'hey, I don't have much stand over height', you know"-T. Ellsworth

    You're turning black metallic.

  19. #19
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    Upset Back to Marzocchi

    Thanks for your comments but since the fork is still under warranty so it's back to Marzocchi!!! Last time it took 4 weeks, hopefully it will be a little faster this time. I've had the fork 3 months and only ridden it for a total of 3 weeks so I'm pretty bummed. Hope it's fixed this time!

  20. #20
    EDR
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    Too much oil, not enough travel, too little, eta doesn't hold down properly......sounds like a common Zoke issue. I had the same issue with my MX Comp, yeah i know, not the same fork but it had an ETA.

    When I changed out the oil and dust seals myself the fork wouldn't travel more then 3.5 inches (with proper preload). When I took out enough oil to make it fully travel the ETA would not hold down nearly as far as before. I ended up compromising on the oil level to achieve the best of both....

  21. #21

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    i have a am1, I think the fork sucks, I feel sorry for people like me who spent lots of money( hard earned money) on the biggest pile crap for 05, The fork is the worst part that I ever bought for any bike I have ever owend.
    never will I buy a marz again.

    .

  22. #22
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    Quote Originally Posted by MK_
    While I haven't seen any reports of Marzocchi seals not holding air at low temperatures, the issues in not at all uncommon, particularly with Fox rear shocks. The fact that the fork held air at your house, where it is warm, and lost it on trail, where it was cold, points in the direction of the seals shrinking enough at low temps to let air past. I would contact Marzocchi and get them to send you a new set of seals or get a set from Enduro.

    _MK

    Talked to another tech from Marzocchi today, I told him that the shock lost air twice when it was 25 degrees when riding. He said that these forks sometimes loose air in very cold weather and it was not unusual. Told him that it wasn't very cold, it was 25 degrees. CALIFORNIA PEOPLE !! Told him I rode my 04 mx pro in the 0 degree range last year and had no problems so they are going to check the fork out when the get it and hopefully replace the seals under warranty.

    Hopefully this helps

  23. #23
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    Well the fork finally made it to Marzocchi. Tech called me today and said steering tube was damaged and both upper and lower stanchions were bent. Sooooo after some discussion, they warranted uppers, lowers, bushings and seals. I had to pay for the steering tube $50 and
    they are using the existing dampening rods and stuff so it's mostly a new shock. Bonus is that the lowers are being replaced with black ones so I can get rid of that ugly tan color. I'm glad they cover most of the items, says alot for their customer service. I just hope it's FIXED!

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