Advice Sought..Slipping cassette in bottom gear.

loxster71
loxster71 Posts: 269
edited August 2014 in MTB workshop & tech
Hi All,

Help needed please.....I have a GT Agressor xcr 2010 model, It has deore shifters and an Xt rear mech, On closer inspection these look ok and the shifting works as expected.
When I work my way down the cassette to the bottom one ( smallest sprocket) and apply power it slips, like the freewheel isn't gripping, But it only does this in the smallest cog not in any other gears?

I can get out of the saddle and give it full beans in the next sprocket up and it doesn't slip so I am confused, any ideas please on what could be causing this.

Thanks for any advice.

J.
Giant Trance X3
Boardman Limited Edition Carbon #344
BMC Streetfire ssx( converted to flat bar Hybrid)

Comments

  • nicklouse
    nicklouse Posts: 50,675
    Sounds like you may not have the correct locking fitted. Have a look to see if the chain is actually touching it , it should not.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • loxster71
    loxster71 Posts: 269
    Hi,
    Thanks for the reply, When you say "sounds like it may not have the correct locking fitted" what do you mean?
    What's "locking" that your referring to?

    Thanks J.
    Giant Trance X3
    Boardman Limited Edition Carbon #344
    BMC Streetfire ssx( converted to flat bar Hybrid)
  • cooldad
    cooldad Posts: 32,599
    He means lock ring.
    I don't do smileys.

    There is no secret ingredient - Kung Fu Panda

    London Calling on Facebook

    Parktools
  • loxster71
    loxster71 Posts: 269
    Can it have the wrong lock ring fitted and still work?

    Please be aware I have no technical knowledge when it comes to repairing bikes so all advice is welcome before I end up taking it to my local lbs.

    The more info on what it could be will be a massive help.

    Thanks again.
    Giant Trance X3
    Boardman Limited Edition Carbon #344
    BMC Streetfire ssx( converted to flat bar Hybrid)
  • cooldad
    cooldad Posts: 32,599
    If the lock ring is loose the smallest cog could slip off the splines of the freehub, I suppose.
    Check if it's tight.
    I don't do smileys.

    There is no secret ingredient - Kung Fu Panda

    London Calling on Facebook

    Parktools
  • The Rookie
    The Rookie Posts: 27,812
    If the lock ring (that holds the cassette on) is too big it will lift the chain off the teeth.

    Or you could have debris trapped between that TOP (smallest is top gear) and the next which will do the same, see if anything is in there, use a screwdriver to remove anything.
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.

Categories