B-screw (tension) not doing anything.

richg1979
richg1979 Posts: 1,087
edited July 2009 in MTB workshop & tech
the B-screw on my rear mech (xtr) does not do anything when i turn it, the top jockey wheel just sits about an inch from cassette.

any ideas?

Comments

  • nicklouse
    nicklouse Posts: 50,673
    and the rear mech is a ........?
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • richg1979
    richg1979 Posts: 1,087
    shimano xtr :?
  • Dirtydog11
    Dirtydog11 Posts: 1,621
    richg1979 wrote:
    the B-screw on my rear mech (xtr) does not do anything when i turn it, the top jockey wheel just sits about an inch from cassette.

    any ideas?

    Has the thread gone?
    Kinesis Maxlight XC

    Orange 5 AM Custom
  • BigStu2
    BigStu2 Posts: 794
    Sounds like the tension spring is broken :(
    .........all
    ...at........work
    fun..................&
    ..no.............no
    .....is......play
  • nicklouse
    nicklouse Posts: 50,673
    richg1979 wrote:
    shimano xtr :?

    Mmm XTR has been around for quite a few years now....
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • richg1979
    richg1979 Posts: 1,087
    sorry its a M-970

    thread is fine as screw moves in and out and rotates spring loaded plate on mech agains flat on hanger.

    the plate on mech mounting is spring loaded and quite stiff just doesnt seam to do anything when screw is turned.
  • nicklouse
    nicklouse Posts: 50,673
    what gear are you doing this in?

    and how did you size the chain length?
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • richg1979
    richg1979 Posts: 1,087
    as ive always done it, same as parktools site ect small ring and sprocket, make sure there is tension on mech and chain not rubbing. large ring and sprocket make sure mech is not straightend with enough travel left for suspension movement.
  • nicklouse
    nicklouse Posts: 50,673
    Odd.

    All i can suggest you do is put it in the small front cog and large rear cog and post pictures of the rear mech with the B screw fully in and also with it fully out and we can see if we can see a problem.

    if not possible then LBS time.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • richg1979
    richg1979 Posts: 1,087
    sorted. for some reason all the adjustment happens at the last 2 turns of the screw can remove the screw and jockey wheel will still not come into contact with cassette. :?

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