Campag Rear Mech Fault

campagsarge
campagsarge Posts: 434
edited September 2007 in Workshop
I have something very bizarre going on with my 10 speed Veloce rear mech (2006). It shifts perfectly, however when on the second to largest sprocket on the cassette, the top of the inner mech cage is clipping the teeth on the sprocket.

It only happens on this gear. I have replaced the inner gear cable and taken the bike to the LBS to look at. They shortened the chain but still no dice.

I have tried another wheel with a smaller second to large sprocket and still the same problem occurs.

Any ideas anyone?

Comments

  • Smokin Joe
    Smokin Joe Posts: 2,706
    I assume that you mean the cage is clipping the teeth on the next sprocket, the largest one in this case?

    Also, did you buy the bike complete and is it still on it's original chain, the length of which will have been set at the factory?

    Lastly, how long has it been doing this and what changes did you or the shop make to the bike before it started?
  • what about the 'B' adjustment screw

    seem to remember that most mechs have an adjuster to set the hight of the
    jockey plate relative to the body

    just had a quick look at my chorus rear mech and there is an adjustment
    screw where the jockey plate pivots.

    have a try of that

    regards - UZ
  • Sorry Smokin Joe, you are right with it clipping the next sprocket - the largest one!

    Nah, I purchased the frame then built it up to an 8 speed campag set up. I upgraded another bike and put that gruppo on this bike (BTW as far as I can remember, it worked okay on the other bike).

    The chain length is troubling me! The bike the gruppo came from is a 56cm frame. This one is 54cm. I took the chain length from the larger 56cm bike as a starting point.

    I found the chain to be skipping around a lot so figured it was too long, so put a post on here to see how to set the correct chain length (which I think you answered - thanks). So I cut the chain to your recommended size.

    The LBS then took another link out of it and he said it is the shortest it will go. Unsurprisingly, when giving resistance (I.E. pedelling on road rather than on a work stand), the rub is less pronounced, leading me to think it is something to do with the tension of the chain (thinking out load).
  • Smokin Joe
    Smokin Joe Posts: 2,706
    Uncle Zaskar's suggestion re the B tension screw would be my next move. I am not sure on the latest Campag mechs whether you turn that in or out to move the mech back from the sprockets, but you will soon see as you turn it. Sorry if you already know this, but the B tension screw is the one which butt's against the edge of the dropout and alters the position of the mech in relation to the sprockets.
  • What size is the largest sprocket?
    I'd rather walk than use Shimano
  • Hi

    Thank you very much for your help UZ and Smokin' Joe and thanks Rob as well. Yep, I can see the B adjustment screw - it is the one that sits on the top jockey plate and it moves the mech up or down. Simple when you know how!

    When I clamped it to the frame I reckon I turned it anti-clockwise, as opposed to clockwise as per the instructions, page 21 step 5 - DOH!

    http://www.campagnolo.com/pdf/7225195_R ... illeur.pdf

    Anyway, it all works beautifully now and I can rest easy.

    I remember the guy in the LBS mumbling something along the lines that Shimano have a B screw but he could not see it on Campag...grrr. Bit surprising that as the shop is family run and has been there for years with the owner riding Campag equiped bikes - I think he was a new mechanic.

    Thanks again I really appriciate your input guys. Top work.
  • glad you got it sorted ok campagsarge :D

    happy riding

    regards - UZ

  • When I clamped it to the frame I reckon I turned it anti-clockwise, as opposed to clockwise as per the instructions, page 21 step 5 - DOH!.

    Consider yourself demoted to campagprivate!!! :lol:

    At least it got sorted :D
    I'd rather walk than use Shimano
  • Ha, ha Rob, I think you are right - extra bike washing detail for me... :lol:

    ...I think I need to read the instructions more too:

    http://www.campagnolo.com/pdf/7225195_R ... illeur.pdf

    ...weekend leave declined...