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  1. #1
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    Rebuilding A Curnutt Air Shock

    I've never done this before. Wish me luck!
    Attached Thumbnails Attached Thumbnails Rebuilding A Curnutt Air Shock-imageuploadedbytapatalk1310864493.389899.jpg  

    Rebuilding A Curnutt Air Shock-imageuploadedbytapatalk1310864595.540465.jpg  


  2. #2
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    Quote Originally Posted by iheartbicycles View Post
    I've never done this before. Wish me luck!
    So my rebuild yesterday was partially succesful. I used 5 weight oil, but really should have used 2.5 weight. Also, putting the XTD Air back together is more difficult than on the coil version, and I ended up with air in the oil.

    I will rebuild again tomorrow with lighter weight fluid and be more careful on reassembly.

    Overall, I feel rebuilding this shock at home is doable - but does require some special tools and parts.

    I bought a strap wrench from Sears for $14.00 and a pair of L bend needle nose pliers for the job. I actually bought a few more tools than this, but the ones that worked are the ones above

    Here's some pics below. My goal was to lube up all interfaces to attain smoother action and to fine tune the internal floating piston for more precise bottom out.

    The shock did feel immediately smoother after the rebuild.
    Attached Thumbnails Attached Thumbnails Rebuilding A Curnutt Air Shock-strap-wrnch.jpg  

    Rebuilding A Curnutt Air Shock-air-chamber-eposed.jpg  

    Rebuilding A Curnutt Air Shock-partly-disasembld.jpg  

    Rebuilding A Curnutt Air Shock-unscrewing-cap-needle-nose.jpg  


  3. #3
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    Quote Originally Posted by iheartbicycles View Post
    So my rebuild yesterday was partially succesful. I used 5 weight oil, but really should have used 2.5 weight. Also, putting the XTD Air back together is more difficult than on the coil version, and I ended up with air in the oil.

    I will rebuild again tomorrow with lighter weight fluid and be more careful on reassembly.

    Overall, I feel rebuilding this shock at home is doable - but does require some special tools and parts.

    I bought a strap wrench from Sears for $14.00 and a pair of L bend needle nose pliers for the job. I actually bought a few more tools than this, but the ones that worked are the ones above

    Here's some pics below. My goal was to lube up all interfaces to attain smoother action and to fine tune the internal floating piston for more precise bottom out.

    The shock did feel immediately smoother after the rebuild.
    heres more pics of the shock torn apart and being put back together.

    Notice that you have to reassemble the air canister and install on the shock body before adding fluid and installing the damper.

    This is what makes it difficult. The damper shaft is attached to the main air spring seal - so when you push the damper shaft in, you are also installing the air spring seal.

    If you falter on this step (as I did) and have trouble installing the air spring seal, you're likely to lose some oil from the cartridge.

    Live and learn, I guess!
    Attached Thumbnails Attached Thumbnails Rebuilding A Curnutt Air Shock-dissemld-2.jpg  

    Rebuilding A Curnutt Air Shock-partly-disasembld.jpg  

    Rebuilding A Curnutt Air Shock-rebilding-3.jpg  

    Rebuilding A Curnutt Air Shock-rebuilding-2.jpg  

    Rebuilding A Curnutt Air Shock-rebuilding.jpg  


  4. #4
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    Looks tough to get it just right. Maybe Foes has a secret they could share on how to
    fill it easier?
    my B+W landscape photos ....www.f45.com

  5. #5
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    Maybe they use some kind of submerged method?

  6. #6
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    Quote Originally Posted by TNC View Post
    Maybe they use some kind of submerged method?
    That is an idea. If I used a submerge method, the air chamber would fill will fluid - but what is unique about this shock (among other things) is that the air chamber comes apart. I could submerge, fill, tighten the cartridge and then open the other end of the air chamber to allow the xtra fluid to seep out.

    Hmmm...

  7. #7
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    Quote Originally Posted by iheartbicycles View Post
    That is an idea. If I used a submerge method, the air chamber would fill will fluid - but what is unique about this shock (among other things) is that the air chamber comes apart. I could submerge, fill, tighten the cartridge and then open the other end of the air chamber to allow the xtra fluid to seep out.

    Hmmm...
    Update. I was able to get the shock rebuilt with 2.5 weight oil and it is working nicely. Haven't ridden it offroad yet, though.

    A couple things - if anyone attempts to do this themselves. Make sure you use 2.5 weight oil.

    Seating the cartridge seal and air spring seal at the same time can be tricky. Go slowly, threading the cartridge top/air spring seal body into the shock body. While doing this, monitor the air spring seal as it presses into the air spring body. If parts of the seal get hung up, push them in with your fingernail or a small flathead screwdriver.

    During this process, some oil is likely to over flow out of the cartridge and into the air spring body. Be sure to depress the air spring schraeder valve, letting as much oil out as possible. Do this several times. Pump up the shock, depress the valve, and repeat until you get it as empty as possible. if you don't do this, your shock will ramp up prematurely.

    This will hopefully make sense to anyone attempting the rebuild!

  8. #8
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    This is a remarkable DIY or self reliance about a Curnut/Foes shock.
    You are the first one.
    Congrat.
    Thanks for sharing your experiment!

  9. #9
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    Thanks for sharing. Looks difficult though

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