Vibration when pedalling hard

mustol
mustol Posts: 134
edited February 2013 in Workshop
Fitted a new chain to my winter bike (2010 Spesh Allez) last week, no problems with chain slipping (a KMC chain - same as I was using before), so assumed cassette and chainrings were fine. However, since replacing it I have a noticed a little vibration (feels sort of 'rough') through the pedals when pedalling hard e.g. pushing up hill in a harder than normal gear - seem to feel it at front of pedal stroke where I'm applying most power (if I use a lower gear and concentrate on pedalling smoothly, vibration goes away). Had a new BB fitted in August and the bike has been running fine since. No sign of any play anywhere. I need to do some more testing to see if it's only on specific chainring/sprocket combinations, but just wondering if the new chain on a slightly worn cassette or chainring could be the problem. (I also replaced my cleats at the same time, but don't see how that could cause this symptom.)

Comments

  • nicklouse
    nicklouse Posts: 50,673
    check the routing of the chain through the rear mech.

    and how the chain sits on the jockey wheels.
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  • mustol
    mustol Posts: 134
    nicklouse wrote:
    check the routing of the chain through the rear mech.

    and how the chain sits on the jockey wheels.

    Thanks for your reply. I'll put the bike on the stand tonight and will check - but if there was a problem with chain routing, surely I'd notice it all of the time?

    The vibration certainly isn't limited to extreme gears where you might get some rubbing, certainly noticed it on middle chainring and middle sprocket combinations. I'd still like to know if the new chain/older cassette or chainring combination could be causing this vibration - just seems like a strange coincidence.
  • Cleat Eastwood
    Cleat Eastwood Posts: 7,508
    I've had this - I did 2 things which elimnated it, so not sure which one was the cure - tightened lock ring on cassette and tightened skewers a 1/4 turn. And do check for oily sludge on the jockey wheels - all too common this time of year.
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  • FoldingJoe
    FoldingJoe Posts: 1,327
    mustol wrote:
    certainly noticed it on middle chainring

    There's your problem - you're running a triple!! ;)
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  • mustol
    mustol Posts: 134
    FoldingJoe wrote:
    mustol wrote:
    certainly noticed it on middle chainring

    There's your problem - you're running a triple!! ;)

    I knew there was a simple explanation - I'm a big girl's blouse!

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