help;sticking marzocchi am 4s.

garsr6
garsr6 Posts: 135
edited November 2007 in MTB workshop & tech
ok i have recently purchased a commencal mini dh 6.3 2007 with marzocchi all mountain 4s @ 160mm travel. whilst trying to set sag i measured between the seals and underside of the crown and there is only 150mm??

i lifted the front end up and pushed down on the fork brace and they moved 10 mm to give the 160mm that they should but they dont stay there and thats before putting the bike back down. any one know why this is happening?

i know oem forks are taiwanese crap but surely i should have 160mm as advertised so i can set sag properly.

any help will be gladly received.
thanks

Comments

  • nicklouse
    nicklouse Posts: 50,675
    is there any air presure in them? or is there a vacum pulling them down?
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • garsr6
    garsr6 Posts: 135
    ive tried adjusting both sides (air)as per manual but its still the same, how would a vacuum happen? how would i get rid? would that happen if there was no air in the positive air chamber?
  • nicklouse
    nicklouse Posts: 50,675
    have you ever put any air in the right leg?
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • garsr6
    garsr6 Posts: 135
    yeah its at 45 psi, and the spring preload is at 15 psi.
  • ride_whenever
    ride_whenever Posts: 13,279
    try putting slightly more in your +ve air than the -ve and seeing if that makes a difference. Roughly 5psi should be enough IIRC
    Neeermad
    Carbon 456
    456 lefty
    Pompino
    White Inbred
  • nicklouse
    nicklouse Posts: 50,675
    garsr6 wrote:
    yeah its at 45 psi, and the spring preload is at 15 psi.

    Ok and how long have you had the bike?

    and try more air in the right leg.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • garsr6
    garsr6 Posts: 135
    three weeks and two rides, will try more air in right leg tomorow. think i may need softer spring too as im not getting full travel.

    cheers guys .
  • nicklouse
    nicklouse Posts: 50,675
    Ok what weight?

    remove air from the spring side. and play with air on air side.

    they could still need some bedding in.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • garsr6
    garsr6 Posts: 135
    about 180lbs with all usual riding gear on, i have given them a good hammering on both runs which was prob about 4 hours all together and i have a zip tie on stanchion which has been sitting about 20 mm below the crown even after some large hits and drop offs.
  • nicklouse
    nicklouse Posts: 50,675
    in that case back to the shop for an oil level check.

    as at 180 you should have more air in the air spring side so you should be able to get the travel to go though its travel.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • garsr6
    garsr6 Posts: 135
    ok will do, thanks. :)

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