Fox Float 36 - No Sag

stingmered
stingmered Posts: 60
edited October 2010 in MTB workshop & tech
I've recently taken charge of a new steed with Fox Foats (36.) I've never owned an all air sprung fork before and am really struggling with the sag. According to the Fox setup blurb I need to run 55 psi for my weight, however at this pressure the sag was less than 5mm, not the 40mm i was looking for. Even with no air pressure in the sag is not more than 10-15mm. As the forks are brand new, is it just a case of waiting for them to bed in a bit? The forks are still fairly stiff through the travel so are they OK to run with little or no pressure in for now?

Comments

  • nicklouse
    nicklouse Posts: 50,675
    forget the numbers and set the pressure to give the required sag ( as covered in the FAQs) also see the Fox set up videos ( see the teck links sticky) for a how too.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Cheers for the quick response, though like I said, I Ignored the numbers and am running it at zero Psi, but still not getting enough sag. I've already followed the Fox video for sag set up, and I suppose my question really is 'is this normal, and will the sag situation improve as the fork beds in'?
  • Anonymous
    Anonymous Posts: 79,667
    How much do you weigh?
  • Are the forks RLC 's ? is the lock out and compression turned fully off.
    The forks will 'soften' up as they bed in but you should need some air in them.

    also have a look at my setup guide:

    http://locotuning.co.uk/tech-info.html

    any queries drop me a line
    Suspension servicing, tuning, parts, setup and race support
    Locotuning.co.uk
  • How much do you weigh?

    A personal question indeed! Ha-ha - 11.5 stone - not 'featherweight' by any stretch. I've always been fairly light over the front of the bike though. Marzocchi forks I had last were coil with air preload/sag adjustment and I ran that at pretty much zero to get 25% sag.
  • Locotuning wrote:
    Are the forks RLC 's ? is the lock out and compression turned fully off.
    The forks will 'soften' up as they bed in but you should need some air in them.

    also have a look at my setup guide:

    http://locotuning.co.uk/tech-info.html

    any queries drop me a line

    Cheers for that - they are Float R so no lockout or compression dampening to affect set up. Looked at the website - nothing there that I haven't already done. I'm not convinced that the static method of measuring sag works that well for me. Thinking about it now, cycling at a slow controlled speed on flat level ground, and allowing the bike to come to a natural stop (i.e. no brakes or sudden movements) would probably work better.
  • Neily03
    Neily03 Posts: 295
    I'm 12st 2lb and fox say I need 69psi in my '10 Float 36 RC2, that's way too high, I run them at 50psi.
  • shm_uk
    shm_uk Posts: 683
    Ooer, I've just ordered a set of Float 36's :)

    Other than taking a bit of time to reach optimum plushness, forks should at least sag the appropriate amount (I would have thunk).

    I'll see what happens when mine are fitted ...
  • P-Jay
    P-Jay Posts: 1,478
    Hmm, how are you positioned when you're checking it.

    36's are long (of course) and tend to be fitted to slacker frames.

    Mine move through the stroke noticeably when I change from seated to 'attack position' I always set my sag in the body position I want them to work best, I.E. over the bars.

    Just an idea.
  • Anonymous
    Anonymous Posts: 79,667
    at 11.5 stone, they should definitely work. I was curious if maybe you were a very light kid, and the atmospheric pressure in the forks might be eenough!

    Definitely no problems getting the sag here, and no plushness issues. Sounds like something is definitely amiss.
  • cheers all for the advice so far.

    @p-Jay I think there may be something in that. just sat on the bike doesn't seem to have much influence and I suspect that 'attack' mode may be required on a slacker bike. I'm out with some mates around CYB this evening, I'll bring the shock pump out and see how it goes.
  • Neily03
    Neily03 Posts: 295
    stingmered wrote:
    cheers all for the advice so far.

    @p-Jay I think there may be something in that. just sat on the bike doesn't seem to have much influence and I suspect that 'attack' mode may be required on a slacker bike.

    If they're new they'll have a lot of stiction making it difficult to get the correct sag. I changed the oil in mine to Rock SVI 10wt and it got rid of a lot of the stiction, it's a lot better than the oil Fox put in them. :)
  • peter413
    peter413 Posts: 5,120
    Fox 36's can be very sticky to start with because of the large stanchions but after they are bedded in they are very plush.

    Wait a bit for them to bed in and if you are still having problems then start to worry
  • Thought I'd do the courtesy of an update. Hammered out the good bits of the MBR on Wed night. Despite hitting some rocky drops at a rate of knots, I’m still only getting about 130mm of travel out of the floats – that’s with pretty much bugger all air pressure in (about 20 psi, too worried about running at zero for now.) However noticed that when riding slowly on the flat the sag seems to have increased, still not up to 40mm but getting there. That said, the forks felt very plush through the travel and soaked up everything in their way. Can’t wait to test them on something a bit more demanding than CYB though.
  • Neily03
    Neily03 Posts: 295
    Are you sure your pump/gauge isn't faulty?
  • Anonymous
    Anonymous Posts: 79,667
    130mm seems about right in normal use. their maximum travel is 160mm, and that will take a BIG impact on the fox36s.
  • I can't be sure the pump isn't faulty until i compare it against another one, but it is a brand new fox pump, so I'm assuming not. Even when I run it down to atmospheric it doesn't make that much difference.

    I'm coming to the conclusion that it's a combo of the forks needing a bit more bedding in and my weird 'light over the front' riding style. This all changes once the trail points down though and the forks seem pretty sick! :D
  • Thewaylander
    Thewaylander Posts: 8,594
    Also remember SAG is set on the rear shock in a sitting position on the front shock your meant to be in the attack position last time i checked.
  • Anonymous
    Anonymous Posts: 79,667
    Also remember SAG is set on the rear shock in a sitting position on the front shock your meant to be in the attack position last time i checked.
    Wrong. It depends what sort of riding you do. A bike (or rider) that is meant to be ridden in the "attack" position should be set like that. On the other hand, a more XC-esque bike, or rider should set the front and rear sag in the normal seated riding position.