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  1. #1
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    Push Industries High Volume (HV) Air Piston Kit

    Sending my Fox F100 RL in for service. I've had it Pushed before, but see there is a HV air piston kit upgrade.
    Does anybody have any experience with this?
    I'm trying to decide if I need it. I weight 200 pounds, ride XC trails with a Trek Top Fuel and don't race as much as I used to. My fork is in great shape.

  2. #2
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    If you are not aggresive enough to use all the travel of your fork, then it's a good thing. Done that myself to my 36 Float RC2 because at the pressure I like to run my fork at, I could not use all the travel even when my compression adjuster was fully open. I removed about 10mm of the piston rod (HV conversion). Now my fork is using almost all the travel even if low speed compression is 4-5 clicks from fully closed.

    Great thing is that this conversion can be undone by adding oil to air spring chamber.

  3. #3
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    I sort of get the goal of the HV air piston kit is to increase the air volume and get a more linear spring rate, which gives good suspension to small bumps and big hits.
    I also see the the 2013 Fox fork line is criticized for having suspension that has spring rates that are too linear, and the fork loses some of its plushness. The fix is to add fork oil to decrease the air volume.
    Seems to be the view looks better from the other side of the fence scenario.
    I don't even know if I'm using all of my travel. My fork feels alright and I run my PSI around 75-90 psi to get the 25% sag.
    I've tried reading some threads on linear spring rate and the conversation got to complex, hinging on physics and chemistry. There is nothing wrong with my fork, nor am I dissatisfied with it. I just want to know if I'm missing out on an upgrade.

  4. #4
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    If theres nothing wrong with the fork and you like the way your fork works, then I see no reason for change.

  5. #5
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    The HV air modification is generally for light riders who can not get full travel. Heavier rider dont normally have the same issues and if they do the mod, tend to have a loss of midstroke support. I would say you are better off without it, but a quick call or email to PUSH will give you a definite answer.

  6. #6
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    I think the same way. It's only the fork is a 2008 and I thought maybe the HV air piston kit was an upgrade on old technology. A lot can change in six years.

  7. #7
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    the kit is not a new air spring, its nothing more then cutting the compression rod to make the air volume larger. Its a modification to the existing spring system.

  8. #8
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    Push says it depends. I would gain small bump sensitivity, a more linear feel (????), and it wouldn't ramp up as aggressively, or early.

  9. #9
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    I had it done by Push a few years back on my 2008 36 RC2.
    The damper tune likely is the bigger change in the performance, it is far better than stock.
    It will get full travel on a hit that makes my hands hurt, but on up to about a 4' drop, there is still about half an inch of travel left. Before the HV mod, I had more than an inch of travel that was never used. So just a little gain there.
    No wallow in technical sections, or brake dive. No mid stroke issues. Possibly a mix of the tune, and the HV mod.

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