Viewing 29 posts - 1 through 29 (of 29 total)
  • Suspension forks only giving 100mm travel instead of 120mm
  • grannyjone
    Free Member

    I have a Specialized Camber Evo 2015 with Rockshox Reba RL 120mm forks. In not a lot of time the forks lost a lot of travel and were about 100mm instead of 120mm. It does seem that they gain a bit of travel if you put more air into them, but this would be above the recommended pressure, making the ride hard and rough.

    I rode the bike to the nearest mechanic who did a full service including seal changes (they were probably on around 2000 miles by this point) got the bike back and the travel had returned to full 120mm.

    However gradually after riding it over the next few months it started getting lower again, noticed at first when I lost around 5mm then not long later I had lost 20mm with the forks now only 100mm again. Under-performing as much as they did pre service.

    The bike mechanic doesn’t know whats wrong, but I think he said that he thinks it could be a faulty valve between the two air chambers? Does anyone know what is wrong ?

    Hope the fork doesn’t need replacing as these are around £400 apparently!

    martinhutch
    Full Member

    Unscrew the foot nut on the air side, stick a rag around a small-ended hex key and stick it through the hole to release the negative side schrader valve which is tucked up in there. You should get a tiny hiss and a bit of oil spraying out, so take the front wheel off first. Take all the air out of the positive side, do it all up and repressurise as normal.

    This, in theory should return your travel temporarily. If it disappears again (I suspect it will), then he’s probably right – the equalisation valve is faulty.

    You can carry on doing that fix every few rides (only takes a few minutes), or replace the air unit.

    plumslikerocks
    Free Member

    Some Rockshox (don’t know if reba’s included) can leak oil from the damping chamber into the lowers, causing the dirk to hydro lock midway through the travel. Cured by changing the seal on the rebound piston. You can buy kits on eBay for just this purpose.

    teethgrinder
    Full Member

    If they are sitting low in the travel at rest, then yes.

    If it’s not getting all travel on compression, the o-ring at the bottom of the damper-side stanchion is worn allowing damper oil to seep into the lowers during compression. This builds up and reduces travel – hydrolock.

    mboy
    Free Member

    Quickly losing count of how many Rockshox forks I’ve had to pull apart and service because this has happened. Sometimes a service fixes it, other times it comes back fairly quickly I’m sad to say.

    qwerty
    Free Member

    Blocked dimple, scratched air shaft, too much factory grease may cause this. Warranty or try a lower leg service.

    grannyjone
    Free Member

    Blocked dimple, scratched air shaft, too much factory grease may cause this. Warranty or try a lower leg service.

    It’s already had a full service but this only solved the problem temporarily

    If they are sitting low in the travel at rest, then yes.

    If it’s not getting all travel on compression, the o-ring at the bottom of the damper-side stanchion is worn allowing damper oil to seep into the lowers during compression. This builds up and reduces travel – hydrolock.

    They are sitting low on rest. When the bike is standing, without my weight (or any other weight on it), the forks are only 100mm.

    I can still use the full travel and bottom out though.

    Unscrew the foot nut on the air side, stick a rag around a small-ended hex key and stick it through the hole to release the negative side schrader valve which is tucked up in there. You should get a tiny hiss and a bit of oil spraying out, so take the front wheel off first. Take all the air out of the positive side, do it all up and repressurise as normal.

    This, in theory should return your travel temporarily. If it disappears again (I suspect it will), then he’s probably right – the equalisation valve is faulty.

    You can carry on doing that fix every few rides (only takes a few minutes), or replace the air unit.

    Thanks, I’ll have to give this a try – or if I can’t get anywhere with it – ask the local mechanic to give this a go

    jonnyrockymountain
    Full Member

    Got some mint condition (only a few rides old) marzocchi LCR 320 forks for sale, that are better and more reliable than your Reba’s, if you fancy a change wanting £195 posted, have a look in my profile

    grannyjone
    Free Member

    Got some mint condition (only a few rides old) marzocchi LCR 320 forks for sale, that are better and more reliable than your Reba’s, if you fancy a change wanting £195 posted, have a look in my profile

    Might consider it if I can’t fix my problems with the Reba’s any time soon

    davros
    Full Member

    Same thing has happened on my 6 months old 2016 reba although mine are under warranty still so I’ll get merlin to take them back.

    grannyjone
    Free Member

    Mine still have a few days left on the warranty but I can’t afford to send them back and miss several weeks worth of riding at this time of year.
    I could still ride my other bike but its not as good as the Camber even with the faulty forks.

    grannyjone
    Free Member

    Unscrew the foot nut on the air side, stick a rag around a small-ended hex key and stick it through the hole to release the negative side schrader valve which is tucked up in there. You should get a tiny hiss and a bit of oil spraying out, so take the front wheel off first. Take all the air out of the positive side, do it all up and repressurise as normal.

    This, in theory should return your travel temporarily. If it disappears again (I suspect it will), then he’s probably right – the equalisation valve is faulty.

    You can carry on doing that fix every few rides (only takes a few minutes), or replace the air unit.

    I took these instructions to my local mechanic and he said that they only apply to the older Reba forks.

    He said that this wouldn’t work on the Rockshox Reba RL 120mm as they only have one valve (which is at the top of the fork)

    martinhutch
    Full Member

    Hmm. I wonder where that satisfying hiss is coming from on my Reba RL 120s when I do that? Must be a small snake stuck inside. 🙂

    They are the 2013 version – does that count as ‘the old type’?

    grannyjone
    Free Member

    christ why are most bike problems so damn hard to sort out

    martinhutch
    Full Member

    Go on, see if you can find the mystery valve that isn’t there…I’m actually interested to know whether the Solo Air design has completely changed in the last two years.

    teamslug
    Free Member

    Might not be related but I had a problem with some new fox 32’s. The are 120mm but were sat at 105mm. I could pull them up to 120mm but they settled at 105mm. I had tried letting air out and reinflating slowly/quickly etc. I put a thread on here and one of the suggestions was to slide two small cable ties between the stantions and the dust seal.As I did it quite a hiss of air escaped but it didn’t cure the problem so I left the cable ties in place and let the air out, reinflated and pulled up on the crown and after a sucking squelching noise they returned to 120mm and have been fine since.

    davros
    Full Member

    My 2014 reba on my camber evo has the mystery air valve, though strangely it isn’t on the service diagrams on the rockshox website…

    bomberman
    Free Member

    If they were new in 2015 then aren’t they still under warranty? If they are then just get your LBS to send them back to rockshox with a note, they are pretty good and should sort them out or replace them under warranty (if they’re still in warranty).

    dirtydog
    Free Member

    If they were new in 2015 then aren’t they still under warranty?

    This, you know you get two years on Rockshox?

    Did your mechanic fit an air spring service kit, or do a lower leg service and just replace dust/oil seals, service means different things to different people?

    Sounds like a pressure imbalance between positive and negative chambers or a vacuum in the lowers.

    RamseyNeil
    Free Member

    The solo air Rebas do indeed have a valve in the bottom of the leg , doing what martinhutch suggested should cure them , possibly permanently , possibly not , try the air valve remedy then send them back if this doesn’t work would be my advice .

    golo
    Free Member

    Just – well a week ago – noticed this with my 120mm Pikes. Read lots of stuff on here and….

    Pumped them to max pressure … used 150psi.
    Stood with the wheel between my legs.
    Gripped the bottom of the wheel with my feet.
    Arms under the bars and…

    LIIIIIFT

    There was a psfshtfttttt gas moving noise and the suspension got longer.

    Back to 120mm and still there after Heaven of the South.

    Don’t forget to let the air back out!

    tomd
    Free Member

    I had a set of 2014 rebas RLs that did this when only a few months old. Taking all the air out and cycling the fork didn’t help, as above this worked for the older dual air not the newer solo air.

    I sent them back and they were repaired under warranty, some sort of sticking valve inside.

    grannyjone
    Free Member

    Just – well a week ago – noticed this with my 120mm Pikes. Read lots of stuff on here and….

    Pumped them to max pressure … used 150psi.
    Stood with the wheel between my legs.
    Gripped the bottom of the wheel with my feet.
    Arms under the bars and…

    LIIIIIFT

    There was a psfshtfttttt gas moving noise and the suspension got longer.

    Back to 120mm and still there after Heaven of the South.

    Don’t forget to let the air back out!

    Tried this. At full pressure (200 psi on the Reba’s) the forks went up to about 118mm. Tried pulling up to get them up to 120mm and it wouldn’t move. Let the air out to get it back to the correct pressure and my travel just went back down to 100mm, as it was before.

    grannyjone
    Free Member

    The solo air Rebas do indeed have a valve in the bottom of the leg , doing what martinhutch suggested should cure them , possibly permanently , possibly not , try the air valve remedy then send them back if this doesn’t work would be my advice.

    I can’t find this bottom valve. Under the forks all there is is Rebound Adjustment on one fork and the other fork has got nothing under it at all.

    martinhutch
    Full Member

    Did you take the foot nut out on the air side? You then stick a smaller hex key through the foot nut hole. You can’t actually see it on the outside.

    You won’t lose the oil in the lowers just by taking the nut out.

    stevemuzzy
    Free Member

    Everyone has missed the 2000 miles before service part….

    grannyjone
    Free Member

    Did you take the foot nut out on the air side? You then stick a smaller hex key through the foot nut hole. You can’t actually see it on the outside.

    You won’t lose the oil in the lowers just by taking the nut out.

    I finally found the valve, pressed it with a hex key and it emptied all the air and some oil came out.
    Pumped it back up with the shock pump and the full travel came back to 120mm!

    Tried it for a blast on Werneth Low this evening and it was working like new.

    Thanks for all the help, looks like this problem is now solved.

    martinhutch
    Full Member

    😀

    I’m sure your mechanic will be pleased to learn about the extra valve too.

    Not convinced it will solve your problem forever though – it may well be sorting the symptom rather than the cause. But it only takes a few minutes to empty and refill if it re-occurs.

    mark90
    Free Member

    Reading this with interest as I have a set of solo air Reba, which are working fine. Just checked the 100mm air shaft I took out (replaced with a 120mm) and there it is hidden in the bottom of the shaft an air valve. Useful info.

    So if this is a recurring problem is guess the simplest fix is a new air shaft, I’m assuming the sticky equalisation valve must be inside the air shaft?

Viewing 29 posts - 1 through 29 (of 29 total)

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