rear derailleur rubbing spokes in lowest gear

JimmyK
JimmyK Posts: 712
edited April 2010 in Workshop
when i am in lowest gear at rear and inner ring at front, there is a rubbing between rear derailleur and spokes , only does this in this particular gear. any idea what could be causing this ?

Comments

  • tptvmbircn
    tptvmbircn Posts: 782
    Personally i would check the mech for bends, assuming all fine pop it into highest cog release the cable and start again following this:

    http://www.parktool.com/repair/readhowto.asp?id=64
  • redddraggon
    redddraggon Posts: 10,862
    Sounds like your limit screw needs adjusting
    I like bikes...

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  • acidstrato
    acidstrato Posts: 945
    hmmm deja vu

    i thought you decided it was down to Quad power and wheel flex
    Crafted in Italy apparantly
  • Monty Dog
    Monty Dog Posts: 20,614
    There are 2 screws on the back of your rear mech cage - tighten the one towards the rear by a turn whilst in the biggest sprocket - it should move away from the spokes
    Make mine an Italian, with Campagnolo on the side..
  • JimmyK
    JimmyK Posts: 712
    is this a common thing to occur ?
  • rake
    rake Posts: 3,204
    be cautious and make it a priority. if it gets draged into the wheel it will be and expensive mess of frame, wheel chain and gears.
  • JimmyK
    JimmyK Posts: 712
    bike is off road until i get to LBS on tues :(

    ive had the bike for over 2yrs and never had this problem before :?
  • rake
    rake Posts: 3,204
    not to worry. it will just need tweaking somewhere.
  • Wheelspinner
    Wheelspinner Posts: 6,673
    If you've never had this problem before on this specific bike, AND you have not dropped the frame or otherwise knocked it, then cable stretch and an adjustment to the limit screws might be the answer.

    Also check whether you have the rear wheel centred correctly in the frame with the QR. DIdn't say whether you have changed wheels at all??

    If you *have* dropped the frame, even lightly, it's possible the derailleur hanger has been bent in very slightly which maks the cage hit the spokes like this. If all else fails to fix it, ask the LBS to check that alignment - there is a special tool for it, which they might have.
    Open One+ BMC TE29 Seven 622SL On One Scandal Cervelo RS
  • Sirius631
    Sirius631 Posts: 991
    I've just recovered from a broken collarbone (2nd time in 3 years) and took my bike out for it's first ride since the accident. I thought everything was OK, all my changes were as crisp as ever. That was until I put the rear mech into the largest sprocket. The mech was wrenched off the frame and dumped on the ground, having tangled with the spokes. The gear hanger was bent, as was the dropout beyond the replaceable hanger. I concluded that the hanger must have been slightly bent from the original accident, as there were witness marks on the rear mech where it had touched down. Moral of the story - give the bike a thorough check before riding again after a tumble.
    To err is human, but to make a real balls up takes a super computer.
  • JimmyK
    JimmyK Posts: 712
    If you've never had this problem before on this specific bike, AND you have not dropped the frame or otherwise knocked it, then cable stretch and an adjustment to the limit screws might be the answer.

    Also check whether you have the rear wheel centred correctly in the frame with the QR. DIdn't say whether you have changed wheels at all??

    If you *have* dropped the frame, even lightly, it's possible the derailleur hanger has been bent in very slightly which maks the cage hit the spokes like this. If all else fails to fix it, ask the LBS to check that alignment - there is a special tool for it, which they might have.


    the wheels are handbuilt 32 spoke mavics with open pro rims and 105 hubs, been atomic war proof so far.
  • The Mechanic
    The Mechanic Posts: 1,277
    I had the same problem on my steel audax bike. It was the mech hanger that was out of line following a dropped bike during a cleaning exercise. I bought a tool from Wiggle and did the job.
    I have only two things to say to that; Bo***cks
  • This happened to me a few years ago.. put rear mech into largest sprocket 28...rear mech was ripped into the rear wheel ..12 spokes smashed Chain broken....and me, 4 teeth smashed out, broken hand, :oops:...