• This topic has 23 replies, 12 voices, and was last updated 10 years ago by Euro.
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  • Air shocks and jumping?
  • Euro
    Free Member

    I had a little tumble on a jump on saturday, and like a bad workman, i’m laying the blame on my RP23 air shock 😆

    I felt the rear kick when i left the lip and witnesses saw back end of the bike do the same. Never had a bike do that before (that didn’t have an engine) and i’m a little apprehensive about doing it again. I’m also slowly beginning to realise i’m a bit old to be a test pilot 😥 so would appreciate some advice please.

    Will turning the rebound down a few clicks prevent this type of thing happening again. Or is there some other setting that might help? THe little blue 3 position dial on the blue lever was set a 1 if that helps. I’m not used to air cans and not sure if this is the kind of thing that they do (unlikely) or if it was suspension ignorance that caused the crash (likely). I’ve done a fair bit of jumping over the years and have hit this jump several times without incident – so i don’t think it’s a rider error issue.

    Just in case you missed it, have a giggle on me 😀

    [video]http://www.youtube.com/watch?v=3P0B5uZ87m4&list=UUPvti4d0R4E6J7p8wPSPmaQ[/video]

    richmtb
    Full Member

    Good effort!

    So did you case the jump or did you just get bucked off as the suspension rebounded?

    scotroutes
    Full Member

    So bad you had to post this again 😆

    mikewsmith
    Free Member

    Sounds like rebound and an unfamiliar bike (did your last post say it was a new bike)

    Before going big on something new I would suggest working up and setting up the bike for you. Old LBS friend always suggested taking the shock pump to a local loop that had everything for a few hours and fine tuning it. Same with a coil really.

    Trimix
    Free Member

    You need to reduce the speed of rebound. So twiddle the rebound adjuster. But the more air you add the less effect the rebound adjuster has. I found on mine when I was running 250 psi it really made bugger all difference. So Ive gone to a CCDB.

    But if you dont need that much air in the shock (I weigh 85kg without my kit) you may well be fine.

    Rebound is very important, as you have discovered.

    The blue dial is sort of like a compresion adjuster, so it wont effect the ping you got as you unloaded.

    Euro
    Free Member

    The ‘buck’ wasn’t that severe tbh, but enough to send me off balance and front heavy. I reckon i could have rode it out but it would have been a sketchy landing. With the next bit of trail being steep and rough, i decide to prematurely ejectulate over the bars. Tuck and roll baby 😀

    bigyinn
    Free Member

    Any particular reason why you posted this up twice?

    Euro
    Free Member

    So bad you had to post this again

    I need help or there’ll be a lot more of these types of vids 😀

    I’d planned on taking the bike (yeah mike, still fairly new to me) and a shock pump to the local hills and having a play about, but the weather’s been so shitty that i didn’t think i’d get much from it.

    Trimix, i weigh about 95kg and when i put in the suggested air for my weight it was horrible (street test d’oh!). I think i’ve got about 160ish in the back and it feels ok for general riding (but a good 40psi less than recommended for my weight). Should it be closer to the recommended 200psi or so?

    Any particular reason why you posted this up twice?

    Not really. I would like help to stop it happening again though. Any ideas at all?

    Stevelol
    Free Member

    You need to measure the amount of sag you’re getting at the recommended PSI, 25-30% of sag should be about right, then adjust the PSI from there depending on what feels right to you. Don’t just set the PSI then bounce around the street.

    grum
    Free Member

    I replaced my RP2 with a DHX5 on my Pitch. I’m pretty crap at jumping but I find the coil shock behaves more predictably.

    Euro
    Free Member

    I think i did the sag thing. I put it a 200psi and stood on the bike and measured how much the band moved. I let a air out until the band moved 1/4 way down the shaft. It still felt hard so i let more out. I guess i should have left it after the first adjustment?

    Grum i’m not sure how many aftermarket shocks fit the stumpy evo, it’s a funny horseshoe shaped thing.

    mikewsmith
    Free Member

    If your not getting on with the shock before you go aftermarket look seriously at tuning and what can be done.

    Get out and tweak it though 🙂 before you hit the big stuff

    scotroutes
    Full Member

    Did you also have the “gate” fully open?

    Euro
    Free Member

    I really should, shouldn’t i 😀

    Take a look at this (clip) of one of many new trail centres to be built over here (N.I). If you like jumpy stuff you may like it. If anyone’s got a few spare minutes, check out some of his other videos showing the new trails. Fast and hypnotic.

    [video]http://youtu.be/TDEynv8_LgE[/video]
    [video]https://www.youtube.com/watch?v=TDEynv8_LgE&feature=player_embedded[/video]

    bah! can’t even get vid to work, i’ve no chance with the shock 😀

    Messiah, it might look like that, but that’s not what happened, honest.

    messiah
    Free Member

    Vid looks typical of someone who has pulled up on the bike while going off the lip… if you do that the rear of the bike will come up more than the front and you will land on the nose (as you have found out). Nothing what-so-ever to do with the shock settings IMHO/E.

    If your unsure about setting up the shock Loco’s site has some good information in the Set-up section.

    Don’t pull up on the bike as you go off a jump and you’ll be fine :mrgreen:

    bigyinn
    Free Member

    Any particular reason why you posted this up twice?

    Not really. I would like help to stop it happening again though. Any ideas at all?
    My first suggestion would be to delete the video from everywhere, nuke it from orbit if need be. 😆

    messiah
    Free Member

    Doofenshmirtz uses Perry’s Universal Delete Button to combine with his Thought Projection Helmet to erase everyone’s mind of an embarrassing video they found of him

    Euro
    Free Member

    So, if i delete the evidence it never happened and wont happen again? 😛

    Trimix
    Free Member

    As said above, set the SAG by looking at the movement of the shock, not the air you put in. The amount of sag you want is a bit of personal choice as different bikes / riders will have different needs.

    For me I go for 15% Sag, as I do a lot of trail riding, not DH all the time. But you need to experiment to see what you like and what suits you.

    For just jumping you really need to get the pump on takeoff right, and the rebound. I dont think the sag will matter just for that.

    But, the coil shock is much better for me – it dosent ramp up (get harder) at the end of the stroke like an air one does. So it behaves the same way all the time. The CCDB also allows lots of fine tuning so you can get your bike to feel just right if you have the time and patients to do it methodically.

    AlexSimon
    Full Member

    Make the rebound on the rear shock slower than the forks.
    This helps bring the front up quicker than the rear and avoid over-the-bars incidents.

    To be honest though, neither the video or the description is going to lead to a definitive answer. Either get someone knowledgeable to take a look or experiment until you’re happy.

    molgrips
    Free Member

    Will turning the rebound down a few clicks prevent this type of thing happening again.

    If the rear did kick you off then yes, it will.

    For jumping, you want more damping than for normal trail riding. Although for small jumps like that you can deal with it if you are expecting it. It depends on the bike, but sometimes you need your rear to be quite slow to avoid this. On my first FS bike, a Fisher Cake, I had the damping set quite fast on the back, which gave a lovely supple ride. However first time on a 24 hour race when tired and not being bothered to move about on the bike as much as I should I ploughed into a bump sitting down and almost got kicked off.

    ndthornton
    Free Member

    My first suggestion would be to delete the video from everywhere, nuke it from orbit if need be.

    What you talking about – thats a great video.
    crashes that you walk away from undamaged are the great moments of mtbing and should be shared for all to see

    Good effort

    Euro
    Free Member

    Cheers for the tips lads. Day off today, so did a bit of building. Day off tomorrow to do a bit of suspension testing 😉


    Euro
    Free Member

    Finally got round to testing after work today. Results just back from the lab:

    Rebound: 3 clicks from slowest (might go 4)

    [video]http://www.youtube.com/watch?v=PAjJ7dGezUk&edit=vd[/video]

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