dual air forks

morleyman200
morleyman200 Posts: 513
edited August 2013 in MTB workshop & tech
Hi all

Just came back from a trip to the peaks and decided to service my forks.
I have serviced my forks a few times in the past with no issues.

The forks in question are rockshox revelations dual air.

I took them apart as per and serviced the air spring, as i normally would. I did not touch the damper side.
put it all back together, topped up the lowers with the oil etc.

When pumping the forks back up, I filled the positive air spring up no problems, set it to my sag etc and all is good, i then pump up the negative spring and as it reaches about 15psi, it then pops off the grey dust seal on the air spring side. The pressure in the positive chamber remains and does not leak, however all the negative pressure is released out the dust seal, i've tried to seat the dust seal back in and tried again, still the same happened.

This is the first time i have come across this and i have serviced a few forks in the past.

Tom

Comments

  • warpcow
    warpcow Posts: 1,448
    You didn't replace the bottom plate of the spring assembly properly. Air you put into the spring is escaping into the lowers. New o-ring(s) probably needed. It's the black disc nearest the bottom in this image (the one held into the bottom of the uppers by a large-ish circlip)

    114311450000_1.jpg
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  • morleyman200
    morleyman200 Posts: 513
    i did put that in, thats the part held by the internal snap ring. will check its seated correctly, and will check the seals.

    Can you run a dual air fork as a solo air fork? ie not putting any pressure in the negative.
  • warpcow
    warpcow Posts: 1,448
    That's definitely where it will be coming from, as it's the only way for air to get out of the spring and into the lowers. I suppose it couldn't hurt the fork to be run on only the +ve chamber, but it'll feel like pooh.
    Commie Meta SL
    Evil Sovereign
    Santa Cruz Heckler (gone)
    On One Inbred (gone)
    Ragley Mmmbop (gone)
  • morleyman200
    morleyman200 Posts: 513
    will it not behave as a standard solo air fork? ill have a gander tomorrow, also is there a metal sleeve which slides over the main piston?
  • jimothy78
    jimothy78 Posts: 1,407
    edited August 2013
    morleyman200 wrote:
    Can you run a dual air fork as a solo air fork? ie not putting any pressure in the negative.
    my understanding is that in solo air forks, there's still a negative chamber, it's just that the one valve pressurises both, and hence the pressure in the +ve and -ve is the same.

    Leaving the -ve chamber unpressurised is not going to be the same at all if I'm correct.
  • ste_t
    ste_t Posts: 1,599
    No. Solo air is just equal pressure in the +ve and -ve, using one valve.

    Dual air you do them from separate valves, meaning you don't need to have equal pressure, but needs to be in the same ballpark.

    Edit: What he ^^^^ said

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