slipping gears

sloxam
sloxam Posts: 861
edited August 2007 in Workshop
my gears feel like they are slipping. the chain doesnt seem to move onto a different sprocket and back again. it feels like the tension just goes in the chain for about 1/8 of a pedal rev and then its back to normal. any ideas on how to fix it?
i hate hills (cos i'm fat)

www.justgiving.com/steven-loxam/

Comments

  • Try to be a bit more specific. Does the chain refuse to move when changing up a gear or down. If this happens when changing up, then try adjusting the cable adjustment at the rear derr by turning the adjuster anti-clockwise a half turn at a time. If the chain refuses to move down a gear then remove the rear section of cable outer which curves down to the rear derr. as this may be causing the inner cable to stick. It may be possible to free this by squirting WD40 into the cable housing.
    This website may prove a help.

    http://www.parktool.com/
  • sloxam
    sloxam Posts: 861
    the slippage happens when i'm in gear, not when changing, thats whats confusing me.
    i hate hills (cos i'm fat)

    www.justgiving.com/steven-loxam/
  • PhilofCas
    PhilofCas Posts: 1,153
    your freewheel may be knacked
  • Phil Russell
    Phil Russell Posts: 1,736
    A couple of possibilities;
    You chain is seriously worn and so does not sit correctly on the cogs. Try lifting the chain away from the chainwheel teeth at the 3 o-clock position. If you can lift 3mm or more your chain is worn.
    Your gears are out of adjustment such that when you ride the chain is trying to move onto a different cog. It then gets part way and sits on top of the teeth, from where it skips and jumps.
    You have a stiff link in the chain that is preventing the chain wrapping around the cogs

    And ... any 2 or all 3 of above.
    Try investigating the above with the bike in a stand or strung up so that you can move pedals by hand ... you may well discover the reason.
    Cheers, Phil
  • PhilA
    PhilA Posts: 26
    This sounds like a knackered freewheel to me. The slipping happens when the pawls inside the freewheel (the things that make the tick-tick-tick noise) are momentarily not catching.

    It can sometimes happen if too much dirt gets in or some grease has got old and sticky. It may be recoverable. Take it to your LBS who will advise as to whether a repair or replacement is necessary.