Cannondale caad8 tiagra

drewduncan
drewduncan Posts: 32
edited August 2012 in Workshop
Hi,

Just bought this bike and supposed to have had the pre safety, gear check etc.

Chain is rubbing on front dérailleur when on small small or big big. Should every gear be rub free or should these gears be avoided due to excessive chain wear anyway?

Thanks for any help.

Drew

Comments

  • superfourben
    superfourben Posts: 59
    I have the same bike with no problem, have you adjusted the hi and lo settings of the deraillieur on the two adjustment screws, is the gear cable slack??
  • drewduncan
    drewduncan Posts: 32
    Thanks - I've not looked at it yet but will do. How u enjoying the bike?
  • buckmulligan
    buckmulligan Posts: 1,031
    You might be able to just about dial it in so that it doesn't rub in those combos (may be slightly easier if you have a larger frame because of the chain angle?) but you're right in saying that you shouldn't really be using those gears anyway. It does stress the chain and after having a chain bust by slamming it into a big-big gear whilst struggling uphill, I try to pay more attention now. Not too painful, but an embarassing experience I do not want to repeat!
  • drewduncan
    drewduncan Posts: 32
    Thanks for the BuckMulligan - like you I don't tend to use those gears - I just like the idea of a new bike being squeak and rubb free for a while!!
  • buckmulligan
    buckmulligan Posts: 1,031
    Yeah totally, that's a very nice bike you've got yourself too! If it's brand new, did they offer you a free service after so many miles? If so, I'd just wait til your first service and get them to sort it out for you. I wouldn't go twiddling the limit screws on your front mech willie-nillie, because if it's been set up properly they shouldn't need touching.

    FWIW, with careful adjustment on my 52cm Specialized Allez, I can keep all but the small-smallest and big-biggest gears from rubbing, but no amount of adjustment will get rid of that. Someone else may be able to confirm my suspicions that it's possible to dial it out on a larger frame. But TBH I prefer that the chain rubs in these scenarios because if I do accidentally cross-chain it gives me a reminder that I should change chainring!

    Enjoy the bike!
  • drewduncan
    drewduncan Posts: 32
    Yeah I've to take it back for 4/6 week service so like u say I'll get them to have a look then. First decent ride tonight and like it a lot. Had the btwin triban 3 since may and wasn't sure if I'd notice much difference but there is. Very happy!
  • jonnym5
    jonnym5 Posts: 76
    Some setups you can get it to just about not rub. Microshift front mechs seem to allow it but shimano is usually a rubfest.

    Check any bike and they will rub as they are no no gears. Usually the trim function on the gears allow you to run them though.

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