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  1. #1
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    Mach 5.7 Rear shock

    Hey guys, I have a new 5.7 that i am having a few setup questions with. Its a large size with a hv rp23 and i weigh 220. It seems that with proper sag @30% I am using all of the travel on the regular on trails that don't warrant it. This is also my first dw link bike. Is this something others are dealing with too? I wonder if the high volume rp23 should have been the standard can rp23? I would like to get your guys take.

  2. #2
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    We originally used the smaller can RP23 on the Mach 5 but the ride was a bit more firm than desired which is why the HV can is used now (on Mach 5 and 5.7). You can run slightly less than 30% if you feel the need for a stiffer ride, just set the sag so the O-ring is on the inside of the red line on your sag indicator. If you ride the shock with ProPedal ON in Position #1 it'll feel like the Mach 5 which is also a bit firmer. Getting full travel is OK as long as you aren't bottoming hard.
    Desert Sunset Calls/Upward, Pain, Perseverance/Welcome Solitude

  3. #3
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    Shim it!

    Read through this thread. DGC's a clever guy.

    The shim helps control the bottom-out while keeping that plusher feel. At 220 lbs, you may be a prime candidate for the normal air sleeve though. I'd try the shim first, it's way cheaper than a new sleeve.

  4. #4
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    Thanks guys, that pretty well answers my question. I def don't want to lose the small bump compliance and its not bottoming harshly if at all. Its traveling far enough for push the o-ring off the shaft though.

    on a side note, i just noticed that the shock is cavitating a bit already. The first 1/8th to 1/4 inch of stroke is dead. Only 20 miles on it. It starts at a 1/4 inch and soon the gap increases. This is the 2nd out of 3 rp23s to do this on three completely different bikes. I'm quickly losing my faith in fox, it seems since they were sold, their products have taken a dive in quality. I will warranty it but i'm probably just going to order the monarch rt-am from push and be done with it.

    thanks again guys for the input, it was helpful.

  5. #5
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    Quote Originally Posted by coolhandluchs
    Read through this thread. DGC's a clever guy.

    The shim helps control the bottom-out while keeping that plusher feel. At 220 lbs, you may be a prime candidate for the normal air sleeve though. I'd try the shim first, it's way cheaper than a new sleeve.

    I wanted to follow up because I think it will be of use to some other machine 5.7 riders. I took your advice and checked out DCG's mod a gave it a whirl. I have a good test ride on it that put the bike through its paces and it is fantastic. Putting the shim in the shock did not take away the supleness of the suspension at all that I can tell. Its still very active. I weigh 225 with my gear and am running the rp23 at 195 psi which puts the sag o-ring spot on with the sag guide supplied with the shock. It ramps up slightly as it goes through the full travel stroke. It was just enough to prevent bottom out but allow full travel. The seal would push the o-ring right to then end of the shock shaft but not off it like before.

    In short, it worked stupendously for me.

  6. #6
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    [QUOTE=the cracker]
    on a side note, i just noticed that the shock is cavitating a bit already. The first 1/8th to 1/4 inch of stroke is dead. Only 20 miles on it. It starts at a 1/4 inch and soon the gap increases. This is the 2nd out of 3 rp23s to do this on three completely different bikes. I'm quickly losing my faith in fox, it seems since they were sold, their products have taken a dive in quality. I will warranty it but i'm probably just going to order the monarch rt-am from push and be done with it.
    QUOTE]

    @The Cracker,

    I don't know exactly what "caviating" is, but on my brand new 5.7 I have some issue with my RP23 as well.

    After just 3 rides it started to make lots of noise (like air mixed into oil somewhere) and looks also like dead for the first 5mm of travel.
    Overall it remains quite fonctional but the noise is really loud and weird (slurp...). I does not disappear with max rebound, so it is not the usual oil sound we know when on very slow rebound.

    Anyway I have already agree to return the shock and FOX will take it under warranty. So I am not to concerned now.

    More curious on how your managed your "cavitation" issue : have you found an explanation / solution by yourself or finally warranty it ?

  7. #7
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    We the people ...

    @The Cracker,

    I don't know exactly what "caviating" is, but on my brand new 5.7 I have some issue with my RP23 as well.

    After just 3 rides it started to make lots of noise (like air mixed into oil somewhere) and looks also like dead for the first 5mm of travel.
    Overall it remains quite fonctional but the noise is really loud and weird (slurp...). I does not disappear with max rebound, so it is not the usual oil sound we know when on very slow rebound.

    Anyway I have already agree to return the shock and FOX will take it under warranty. So I am not to concerned now.

    More curious on how your managed your "cavitation" issue : have you found an explanation / solution by yourself or finally warranty it ?[/QUOTE]

    Perhaps i am misusing the word. By cavitating, i am referring to the shock basically having zero resistance in the first part of the stroke. which feels to me like a the dampening oil being contaminated with air bubbles which doesnt allow the compression shims to work properly. I am not saying that is what is happening but thats what it reminds me of.
    I looked it up, just to make sure i wasnt too far off base, always learnig.
    cav·i·ta·tion   
    [kav-i-tey-shuhn] Show IPA
    –noun
    1.
    the rapid formation and collapse of vapor pockets in a flowing liquid in regions of very low pressure, a frequent cause of structural damage to propellers, pumps, etc.
    2.
    such a pocket formed in a flowing liquid.


    So the day my shock was really annoying me it was 20 degrees out and was new. Since it has warmed up and if its still doing it, i can not detect it. So im going to let it ride for now. Like you mentioned, it worked well other then that and now its working better. Im not sure if i will send it in for warranty or not. The one i had in the past started with a barely noticeable dead spot and within a month it grew to over 3/8ths of an inch before resistance could be felt. That one i sent to push for a full rebuild and it worked like a champ. I will post if the rp23 becomes an issue. BTW every time i get done riding, i cant help but looking forward to the next one, this bike is so great. Im impressed with it.

  8. #8
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    Good to hear that it improved with time for you

    +1 : I love this bike, it is by far the most capable all-mountain I ever rode, and so much fun you can't resist to jump on it even when it's -5°C on a sunday morning like here nowadays

  9. #9
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    Quote Originally Posted by kenbentit View Post
    We originally used the smaller can RP23 on the Mach 5 but the ride was a bit more firm than desired which is why the HV can is used now (on Mach 5 and 5.7). You can run slightly less than 30% if you feel the need for a stiffer ride, just set the sag so the O-ring is on the inside of the red line on your sag indicator. If you ride the shock with ProPedal ON in Position #1 it'll feel like the Mach 5 which is also a bit firmer. Getting full travel is OK as long as you aren't bottoming hard.
    I weigh 210.. the problem I had with the earlier RP23 the ride was too soft. It would wallow through the climbs. Propedals settings did not make any difference on the bike handling.
    is it different now?

  10. #10
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    Quote Originally Posted by mgfjd12 View Post
    I weigh 210.. the problem I had with the earlier RP23 the ride was too soft. It would wallow through the climbs. Propedals settings did not make any difference on the bike handling.
    is it different now?
    Was this on a Pivot bike? The wallowing could easily be a function of rear suspension rates not being matched to the shock/spring tune correctly or vice versa.
    The same shock will ride very differently on different frames even if they have the same total travel.

    Sent from my Nexus S using Tapatalk

  11. #11
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    The newer RP23's have the boost valve technology which helps control bottom out.
    Desert Sunset Calls/Upward, Pain, Perseverance/Welcome Solitude

  12. #12
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    My rp23 boost valve is getting worse after six months ride, maybe send it to tftuned. But can they change way the shock work? I just want sag to 20% but as comfortable ride that when sag is 30% . Even possible..

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