Viewing 40 posts - 41 through 80 (of 110 total)
  • Pike Fork Problems Light Rider
  • tymbian
    Free Member

    @ articularslinky. ..I wouldn’t take any notice of the recommended Psi on the fork leg. I’ve a fighting weight of 200lbs with a full camelback, recommended pressure for me was 95psi. At this setting I was only getting 10% sag and very sore hands. I’ve had to reduce to 60psi and would turn the LSC nearly full on when hitting roots dips bumps etc.. otherwise I’d bottom out on pathetic small stuff. Last weekend I added two tokens to the one that was already there and pumped up again to 60psi. When I get your next I’ll report back.

    So let your pressure down to about 40 psi, run no lsc, push the red rubber band on the fork stancion all the way to the fork-leg stand up in the attack position, dismount slowly not moving the red band and see where the sag lies. I’m happy at about 22 -25%

    moshimonster
    Free Member

    Errr, generally a heavier rider will need a faster rebound setting for it to push back at the same rate. The general rule is to compress the fork and have it fully extend just after you lift the front wheel, then go from there.

    You’ve misunderstood what I was saying. Any given absolute rebound setting on the damper will be effectively faster for a heavier rider as the damping ratio for the heavier rider will be much lower. It’s a fundamental theory of damping i.e. heavier mass will be less damped for the same rebound setting.

    So a rebound setting that is fast for a heavy rider will be much slower for a lightweight rider. You cannot define how quick or slow any particular setting will be without reference to the mass.

    Another way of trying to describe the above is that a heavy rider will need a higher spring rate to maintain the same damper displacement and therefore more energy is stored up in the compressed spring which the damper has to control on rebound.

    moshimonster
    Free Member

    There’s no high speed compression dial on Pike forks and most are effectively a crap alternative to getting the right shim stack setup for you.

    Agreed, you cannot adjust it. But it could still be an issue if the non-adjustable setting happens to be too high. That was my point there.

    moshimonster
    Free Member

    Personally I’m a little heavier than you and even then I’m right on the end of the damping adjustment of my Pikes

    Which end of the adjustment? Low or high? At 65 kg I would imagine you are running out of adjustment at the low end.

    Northwind
    Full Member

    Low on the compression, aye. Still considering trying dropping down to 2.5W, though tbh with these sorts of changes differences in brand viscosity might make that sort of change pretty chancy. Tehy’re not terrible, they’re just not as good as they should be.

    moshimonster
    Free Member

    Forgive me, tired. To clarify my last post, that doesn’t take into account changes in spring rate. Harder springs will require more damping, but I’ve found light riders often need to run their forks a little bit slower once the rebound has been adjusted for the spring rate. They tend to be less capable of muscling a bike thats bucking around because of their weight and strength and tend to prefer a bit more chassis stability over all out grip.

    I’m wondering though whether because the forks ending stroke rebound is factory set, that it’s overdamped for her weight and the fork is packing down on extended rock gardens. I’d place a bet on this being the issue.

    Just read this after writing my last response above to your earlier post! I see we are actually in agreement that a heavier rider will always need a higher absolute damper setting because of the corresponding higher spring rate.

    I also agree that it may well be packing down on repeated hits due to being over damped. That would certainly explain the pinging off everything! I really cannot imagine that it could possibly be underdamped on a mid setting for her weight. That makes no sense at all to me.

    moshimonster
    Free Member

    Low on the compression, aye.

    I’m not surprised to be honest. Even heavier guys like me usually only run about mid setting on compression on a Pike and even then it’s a compromise between anti-dive and small bump sensitivity.

    moshimonster
    Free Member

    The ‘rapid recovery’ circuit is deliberately set to be much faster than the rest of the rebound circuit, so the last thing it’s going to be doing is getting stuck right in the deepest travel.

    Probably not packing down then in that case.

    moshimonster
    Free Member

    The “bracketing” method is a good way to go, but you could save a bit of time by starting off from pair 2. Max rebound or compression are both going to be way too high. I think it’s fair to say that the optimum settings for a lightweight rider are going to be on the low side.

    Tom_W1987
    Free Member

    Agreed, you cannot adjust it. But it could still be an issue if the non-adjustable setting happens to be too high. That was my point there.

    Yup, this is a possibility,

    My understanding of rapid recovery is that it’s only about 10-15 percent faster than normal, I’m not sure but perhaps not enough to guarantee that it’s fast enough for her weight? She’s 40lb lighter than me and I’m on the skinnier side of average for a guy. Maybe Loco could chime in.

    IMO a decent reshim from LOCO, TFtuned, JTech or Avalanche (who do a lot of other mods to the stock damper as well) will sort her issues.

    moshimonster
    Free Member

    I wouldn’t take any notice of the recommended Psi on the fork leg. I’ve a fighting weight of 200lbs with a full camelback, recommended pressure for me was 95psi. At this setting I was only getting 10% sag and very sore hands. I’ve had to reduce to 60psi and would turn the LSC nearly full on when hitting roots dips bumps etc.. otherwise I’d bottom out on pathetic small stuff.

    Sounds like you’ve gone from one extreme to the other. The approach I take is to set the pressure so I use most of the travel during the course of a ride without any harsh bottoming. I’m about the same weight as you and currently running 85 psi with about 5 clicks of compression – early days yet though on this fork. I don’t take much notice of front sag as it’s quite hard to measure accurately when stationary as the stiction really makes a difference. FWIW it was showing about 15% I think. Feels a bit too harsh on first impression, but I wouldn’t want to drop the spring rate too much and rely on the compression damping to prop it up.

    The recommended Psi settings on the fork leg can only ever be a very rough guide as it depends a lot on what trails you are riding and how aggressive you are. A pro rider taking big air off everything and charging through rock gardens is going to need a much higher pressure than an average Joe pootling around follow the dog at Cannock. If you take account of your terrain and riding style you can usually get an idea if you need to be under or over the average recommendation.

    Tom_W1987
    Free Member

    What Moshi said, PSI can even depend on whether you run flat pedals or spds. Riders who run flats tend to ride further over the back so require a softer fork to gain grip on the front.

    Suspension setup on a bike is very dynamic/holistic. No one area can be changed independently without consequences in other areas, you have to look at the bike setup and rider style as a whole. Basically you cant just tweak one setting and expect everything to be perfect, she might be running to much pressure in the rear pushing her over the front to much on a descent etc etc, ot to much sag on the back requiring her to run to soft a setting on the front etc etc.

    The dude who’s running full low speed comp and only 60 psi…bad idea as Moshi said again….damping can cause a fork/shock to choke up and spike, you really want to be running a harder spring rate with a bit less damping.

    Fairly surprised loco isn’t cutting through all the sillyness in here.

    moshimonster
    Free Member

    IMO a decent reshim from LOCO, TFtuned, JTech or Avalanche (who do a lot of other mods to the stock damper as well) will sort her issues.

    Probably the best call once the OP has established that she can’t get anywhere with the standard range of adjustments.

    Does anyone know if Juliana bikes have their Pikes and rear shocks custom tweaked for lighter riders as part of the women’s specific package – similar to Specialized? Or are they just bog standard tune? It doesn’t say much on their website.

    Tom_W1987
    Free Member

    I don’t think they do, it’s just a brand name alteration with some added pink, which is kind of **** crap of Santa Cruz and one reason why I ignore their products these days, would rather just buy a Kona/Nukeproof/YT and get the suspension tuned properly.

    moshimonster
    Free Member

    you really want to be running a harder spring rate with a bit less damping.

    Now we’re talking the same language! I’ve always believed in the basics. Springs control displacement, dampers control velocity. When you start trying to do it arse-about-face with insufficient spring rate and overdamping it usually goes wrong. My professional experience is with racing car dampers and bikes are a hobby, but the principles are exactly the same.

    moshimonster
    Free Member

    I don’t think they do, it’s just a brand name alteration with some added pink, which is kind of **** crap of Santa Cruz and one reason why I ignore their products these days, would rather just buy a Kona/Nukeproof/YT and get the suspension tuned properly.

    I think that’s a bit harsh, as they do look like very nice bikes! But I’m a bit disappointed if they haven’t made the effort to custom tune the dampers for the ladies. I know its always a compromise and law of averages with these things (hence why a personal custom tune is always going to be the ultimate) but you would expect some sort of women’s specific tweaking at the price point.

    Reason I’m interested is that my wife is on the lookout for a new bike and really likes the look of the Juliana bikes. But I’m starting to think Specialized might be taking the women’s specific thing a bit further with custom damper tunes etc. A Juliana is going to be a very expensive option if it’s going to need custom tuning on top of the base setup.

    Tom_W1987
    Free Member

    They are nice frames moshi, no doubt about that. But considering the price and the level of attention of detail that goes into the frame, I kind if expect the same for the next most important set of components. :S

    Seriously, spend your money on a custom tune and an aluminium frame.

    I’ve always wondered why Jedi and loco dont partner, Jedi taking beginner or intermediate riders….analyses their riding…passes on details to loco who gets a new customer….jedi gets cut of suspension tune.

    Im a bit pissed but I thinj this would be brilliant, custom tunes can help beginners through to advanced riders as they all have entirely different needs that cant be catered to by a bog standard factory tune.

    moshimonster
    Free Member

    According to Bart Bentjens it’s one of the reasons womens World Cup XC riders will often favour HT over FS, don’t how true this is but he seems to know his stuff, the issue relates to the breakaway force required to get the suspension moving.

    I’d agree that stiction/friction/breakaway force or whatever is certainly an important factor, but I would have thought in 2014 a half decent fork/shock would have low enough stiction to work well enough for even the lightest of rider. Whether it would be faster or slower than a HT in a race environment is a different sort of question really. Racers will always sacrifice comfort over speed if they need to.

    Tom_W1987
    Free Member

    Meh, rear air shocks are stilly pretty sucky compared to a good coil on the right kind of track 🙂

    moshimonster
    Free Member

    Seriously, spend your money on a custom tune and an aluminium frame.

    Was thinking of getting her a Specialized Rumor and going from there. Would possibly consider custom damping on top, but only if she’s not happy with the base tune. She’s pretty much average weight and height for a woman, with average skill level and aggression, so I was hoping the factory women’s tune would be in the ball park. She’s had problems in the past with bog standard “man” tuned forks. I remember a Fox Talas she had (circa 2004) basically wouldn’t move even on the lowest of pressures – loads of stiction.

    moshimonster
    Free Member

    Bedtime now for me! Thanks Tom for the discussion, very useful info.

    moshimonster
    Free Member

    Meh, rear air shocks are stilly pretty sucky compared to a good coil on the right kind of track

    Ah ah! Still run a coil spring on the back of my old trail bike for that reason alone. Cheers.

    moshimonster
    Free Member

    It’s not going to ramp up significantly in the first half of the travel no. But it does definitely make a difference, maybe not a huge difference but a difference nonetheless. I’m just saying try it, i’m not saying miracles are going to happen. I just know that loads of LSC and high air pressures are not going to make for a comfortable ride!

    Just seems like the wrong approach for a very light rider on a 150 mm travel fork. Why would she need the extra progression at the end stroke? It’s the sort of thing heavy aggressive riders need to stop the fork bottoming out when landing big jumps.

    I’m still struggling to understand why the OP’s fork is apparently diving massively under braking when the air pressure is already set on the high side for her weight. Especially since Pikes are well known for good support under braking dive. Maybe it’s leaking air?

    artic – it would be worth checking your air pressure post ride to make sure it’s not going down.

    NorthCountryBoy
    Free Member

    I recently fitted a set of new pikes after using fox air forks for years.
    About 5 people I regularly ride with have them now and all love them.
    However all agree that the recommended air pressures on the sticker seem too high I weigh 80kg and I’m running 65 psi with 1 token 26″ wheel version
    It sounds like the fork is just too stiff and basically not working for you.
    I would try running it a lot softer for your weight.
    I’m thinking 45/50 psi and try it. Bet it’s not too far into sag even that low on pressure.

    poah
    Free Member

    When I got my forks I made sure the rebound and LSC set to min. I set the sag to 30% and then adjusted the rebound using the push down pull up method by setting the rebound to slowest then pushing down on the forks and pulling up. then adjust the rebound so the fork extends before you can pull the wheel of the ground and set it one click slower before going for a ride. the LSC depends on the trail I’m riding.

    obviously this works for my personal taste and may not suit everybody

    tymbian
    Free Member

    Hey Moshi….Mr 200Lbs & 60 psi/ three tokens here…

    I’m at 60 psi no lsc. for local bridalways. There’s no gnarly trail in front of my house unfortunately. Running more air ( is this what you mean by higher spring rate ) loses most if not all small bump compliance and gives a very harsh ride. If I do happen along a rougher part of a trail I crank up the lsc…what else can I do? I seem to have a fork that sacrfices support for small bump sensitivity.

    chiefgrooveguru
    Full Member

    Adding bottomless tokens reduces the air pressure required to support a given amount of sag. If the above graphs are correctly scaled then putting in three tokens halves the pressure to maintain the same sag as with no tokens.

    Don’t forget to set fork sag in the attack position, not sitting, and to make sure you’ve jiggled it past any stiction before sliding the O-ring right down.

    tymbian
    Free Member

    The way I understood the graph is that the more tokens you add the more force is needed to achieve more travel. The charts show that adding more tokens doesn’t massively affect the force needed to activate the first part of travel ( the part of the travel I need for small bump sensitivity) thus allowing me to keep the 60psi for SBS without cranking the lsc up to stop me blowing through travel on the small stuff..

    fr0sty125
    Free Member

    I would say thay pinging will be the fact you’re riding a high spring rate for your weight as well as having little rebound dampening.

    The fork is probably spending a lot of time in the early part of the travel compressing slightly then rebounding fast acting like a pogo stick.

    My suggestion would be drop the spring rate so you have 25-30% sag and add a good ammount of rebound dampening to slow the rebound down.

    You can run a click or two of LSC to help with the brake dive. But I’m going to be honest im surprised you are feeling much dive with spring rate that High.

    deanfbm
    Free Member

    OP – What are you comparing to with this pinging sensation, what have you ridden before?

    I’m asking because i think it would be good to establish if you’re bumped on on the travel from before looking for certain things which aren’t actually possible.

    Most of these threads on STW normally come about from people expecting “good” suspension meaning that it eradicates all sensation of any and every bump on the trail , which in reality is never, ever going to happen unless you have 200mm+ of suspension and run 50%+ sag. But then that would actually be terrible suspension.

    Obvious thing would be too high tyre pressure and too little rebound damping.

    The diving is either to much braking or too little air pressure.

    Toppling back sensation – rear shock too soft or just a new, bigger bike to you and it’s a new sensation you have to get used to. Bars too high? Climbing position correct?

    cruzcampo
    Free Member

    articularslinky – Member
    JCL – I actually have a little too much air in the fork 60psi compared to the 45psi recommended – trying to combat the issues – also my tyre pressures are very low – 17 front and back (tubeless) – again trying to combat the issues. So I have exactly the opposite going on at the minute

    I might be a girl but my technique is just fine in technical climbs they are usually my favourite

    Not read the whole thread but 60psi IMHO is way too high.

    I’m a 90 kilo rider and have mine at 50psi, with fully open LSC, and no tokens. Rebound 4 clicks away from the turtle.

    Tubeless tyres pumped to 33psi.

    Fork is a dream, and very surefooted, with plushness all the way to the moon 😀

    Try something like the above, vast difference to your settings but then you can find some inbetween ground.

    tymbian
    Free Member

    @ cruzcampo. What type of trails are you riding and what’s your sag?

    cruzcampo
    Free Member

    @tymbian

    50 psi my sag is at 19% approx, thats stood up on the bike with all my kit on.

    Ride in and around the peaks, so all natural trails really, they perform best on rutty stuff i’ve found, you can pretty much just point and shoot and they traverse beautifully across the trail.

    For my weight I should be running 75-85 psi, but that just gives a harsh pogo stick 😆

    tymbian
    Free Member

    I’m 95kg running 60psi, 3 tokens in an attempt to stop blowing through travel .. if I ride a bomb-hole I’d use all travel so makes me worry that I’d have insufficient damping if I was to have less psi in….haven’t really been happy with my pikes since day 1.

    jedi
    Full Member

    tomwiko, i have just started getting looked after for my fork and shock servicing by tftuned. i dont get forks etc… just servicing. i always recommend tftuned and loco tuning anyway

    chiefgrooveguru
    Full Member

    FYI I’m just under 80kg, running 60 psi & 2 tokens (25% sag), 7 clicks of low speed compression, 5 clicks of rebound (so on the faster side).

    tymbian
    Free Member

    90kg rider 50psi no tokens 19% sag
    80kg rider 60psi 2 tokens 25% sag

    Doesn’t make sense…..

    svalgis
    Free Member

    I guess shock pumps must struggle with accuracy at low pressures? I’m about 62kg and get 25% sag at 50psi and 1 token (and occasionally bottom out).

    JohnnyPanic
    Full Member

    90kg rider 50psi no tokens 19% sag
    80kg rider 60psi 2 tokens 25% sag

    Doesn’t make sense…..

    +1

    There must be something anomalous going on here. Different pumps, different ways of measuring the sag, different variants of the forks, maybe some have more grease in them – influencing sag???

    FWIW
    150mm 26″ RCT3, 85Kg, just gone down to 65psi & one token.
    No LSC. 3 clicks from slowest rebound.
    Rides great mostly, small bump could be better, on rocky Peak District downhills (up to 1ft drops etc) uses all but the last inch.

    fr0sty125
    Free Member

    Using all but the last inch on 1ft drops? 😯

    Or with that psi?

Viewing 40 posts - 41 through 80 (of 110 total)

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