Marzocchi Fork Maintenance De-Mystefied?

Discussion in 'Trials' started by motobene, Oct 22, 2014.

  1. motobene

    motobene Motoing for 49 years Supporter

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    Interesting the added wear from being... not sure what (puzzling).

    BTW in this design they are meant to be able to pass through. First time that happened to me I was like, WT...

    The modern bushings are steel with copper flash and Teflon-like stuff. Very durable. They aren't meant to run tight on the stanchions and there is some clearance for a little felt play.

    In the very old days it was chrome plated steel on steel or cast aluminum and quite prone to wear. "They don't make them like they are used to" and thank goodness!
    #61
  2. DerViking

    DerViking Shred

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    Thanks all. Finally had time to reassemble. The Hell Team guide to bleeding worked really well, and made the most sense to me, and I was able to get it all bled and reassembled fairly easily. Clamping the various parts in a vice is critical. The only really tricky part turned out to be removing the circlip in the bottom of the cartridge without losing it. I shoved the bottom piece up as far as I could against the spring, then held it with a dental pick through one of the large holes. Getting the middle piston back in was also fairly challenging. The o ring really wants to get caught on the lip. The oil gyser when it finally goes is pretty hilarious. Wear glasses.

    I used 7w bel ray fork oil at Motobene's 6" down. I think the spec is 5w, but I weigh 210lb dressed or thereabouts, and have always had my adjuster bottomed out, maybe now I'll have a little adjustment. Rebound is still plenty quick.

    One note, my rebound adjustment was stuck following assembly, seemingly under compression greater than normal. It would seem that dialing them all the way down for assembly is the right call.

    Edit. It's worth mentioning that it took about 750 ml of oil to do both legs.
    #62
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  3. Buschog

    Buschog Long timer

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    Resurrecting an old thread. Had to replace the seal in the rebound (right) fork on my 2015 txt 280 pro.

    I have the job done,and back on the bike. I went for 2 quick rides in the street. The first to realign the front end. The second, to romp on the suspension. I did probably a dozen BIG wheelies with a big preload and hard unload to lift the front sky high with "force". Then slamming it back to the ground.

    No clunking or untoward sounds were heard. So, my hopefully, stupid question is this. If I foobarred the job, would i hear something straight away, or does it come on in time?
    #63
  4. jeffs2200

    jeffs2200 Adventurer

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    You should know pretty quickly, it really is not as hard of a job as people,ale it out to be. Look up the document from Hell Team. Very good step by step instructions.
    #64
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  5. motobene

    motobene Motoing for 49 years Supporter

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    Jeffs2200 is right. If you aired up a cartridge you'll be topping out first thing.

    So glad I have Tech forks now :-). Easier, but given the disincentive of doing more disassembly just to refresh oil on a fairly new bike, I did the oil change around the cartridge method on the Tech as well. Worked great!
    #65
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  6. Buschog

    Buschog Long timer

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    I asked because, even though the seal was only bad for 2 relatively short rides, maybe 5 hours total, there seemed to be very little oil in the leg.

    I filled the lower to the very top, and stroked the cartridge slowly (while tapping it with a soft faced hammer), watching massive air bubbles perk out. Dumped that oil out, refilled and repeated. I knew/know I was taking a chance on have to do a full tear down and bleed, but it felt like the right thing to do.

    After I replaced the seal. I left the spring out, with the upper collapsed down all the way, and i was amazed at how much the oil had risen in the upper (from the space taken up by the upper). It was maybe 2 inches from the top. I set the oil level to 160mm, per spec.

    In retrospect, I don't think the oil was low to begin with.
    #66
  7. motobene

    motobene Motoing for 49 years Supporter

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    Glad it worked out! You did some smart things to get some air out.

    The stiffening by the secondary, trapped, air spring is more substantial than is often assumed. Personally seeing the oil rise up fast and high helps make sense of the importance of oil level.
    #67
  8. Takataka

    Takataka Been here awhile

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    I've just replaced the oil in my 05 Pro forks using the rinse and repeat method.

    Rebound damping is working and adjusting nicely however the compression damping seems to do nothing.
    Forks blow through the full stroke pretty easily ( I can just about do it from bouncing the front wheel and I'm only 65kg) even with the adjuster right down.
    I think the compression damping had been minimal before the service as well.

    Should there be more and should it be more responsive to adjustment?

    Any common faults causing this?
    #68
  9. motobene

    motobene Motoing for 49 years Supporter

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    The 2005 forks are open cartridge, so no crazy bleed routine. Compression damping is on the left side.

    If your C adjuster at full + isn't slowing down the forks much, check that your cap is more threaded onto the cartridge rod. If it's back way up on the rod threads the adjustment is useless and you'll always be at minimum resistance.
    #69
  10. Takataka

    Takataka Been here awhile

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    Ok thanks will have a look and see what I can find
    #70
  11. Takataka

    Takataka Been here awhile

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    Ok I went back in and I think you were correct. I threaded the cap all the way on but then had to back it off a couple of threads so that the top cap would tighten down against it.
    I then loosely assembled without the spring and compressed the fork rapidly by hand to test the action.
    It's now responding to adjustment.

    The compression damping really only seems to come in near the bottom of the stroke to control bottoming but that's possibly the way it's designed. Anyway it's the result I was wanting as I was experiencing a few hard bottom outs during my ride yesterday.
    #71
  12. Wingboy

    Wingboy Been here awhile

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    Another thread revival.Pulled the forks off my 2011 Ossa this morning.When you have too many bikes,things get neglected sometimes.It will be interesting what kind of primordial goo comes out of these.They don't leak and seem to function fine albeit there isn't much adjustment available.They are in the laundry tub inside where it is warm.It's -20c out there! I'll post more pics later. P3080029.JPG
    #72
  13. Wingboy

    Wingboy Been here awhile

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    Wasn't as bad as i thought it would be.The first owner (year and a half) must have changed it at some point.But it was really stinky! Compression side done.i think i'll just flush n fill as the op did on the rebound side.I used 50/50 5wt/10wt Silkolene.It was in the cupboard. P3080030.JPG P3080031.JPG
    #73
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  14. Wingboy

    Wingboy Been here awhile

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    Better things to do than finish this. P3080032.JPG
    #74
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  15. D2W

    D2W Been here awhile

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    Another good possible-find in the cupboard is AFT; I believe it's about 7W5. I've used it with success in my forks.

    Slightly off topic: I saw a great parody t-shirt of Simon and Garfunkel by Guinness: "Hello darkness my old friend. I've come to drink with you again." :drink
    #75
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  16. tomatoe333

    tomatoe333 Long timer

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    For a minute I thought there was a fork tube in your beer glass...
    #76
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  17. motobene

    motobene Motoing for 49 years Supporter

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    Yup, the newer Zoke closed cartridge on the Ossa. All the newer forks are so well made they tend to trash the oil very slowly. That could have been the original oil.
    #77
  18. Wingboy

    Wingboy Been here awhile

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    Some of the oil from the rebound side.Flushed it 3 times and got a little bit more dirt out.Quality seals is the key i think.Very stinky again tho. P3130044.JPG
    #78
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  19. Wingboy

    Wingboy Been here awhile

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    A word to the wise.Watch your thumb when taking the cap off or putting it on. P3130046.JPG
    #79
  20. motobene

    motobene Motoing for 49 years Supporter

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    That's a job for super glue with baking soda sprinkled on!
    #80
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