Rear Campagnolo shifting - mid cassette

jamie4759
jamie4759 Posts: 117
edited March 2015 in Workshop
Afternoon all. My Condor bike has a Chorus groupset (2014). It has recently had a new front mech and chainset fitted and the shifting from the middle of the sprocket (12-25) up to the next sprocket is hit and miss. I would say that 99% of the rest of the shifting is great. I have had new cables and a chain and cassette fitted and the problem seems worse. The mechanic that fitted the new kit is a very experienced and well qualified Campagnolo trained mechanic and other mechanics have also looked at the bike, but, the shifting is still inconsistent. When the bike is in a stand it works better. I find that when in the big ring at the front, and the middle sprocket of the cassette, the chain rattles and won't go up to the next sprocket, and it stops rattling if I click back down again (as if to reset it). It then goes straight into the next sprocket up when I change gear. It's almost like it needs the reset before it will work. I am starting to dread going out on the bike. Anyone else have this with Chorus or Campag? I did wonder whether there was anything wrong with the frame alignment, such is my paranoia about the issue!!!!

Comments

  • crikey
    crikey Posts: 362
    Sounds very much like a cable issue, and it's probably to do with the cables settling in after all the work you've had done. Give the barrel adjuster on the derailleur half a turn anti-clockwise and try it out. Try it out by riding it up and down the street, not in a bike stand.

    If not, take it back to those 'experienced', 'well qualified', 'Campagnolo trained' mechanics and tell them to get it sorted.
  • jamie4759
    jamie4759 Posts: 117
    I have, but none can sort it out!!!!!!! I have tried the riding up and down the street as well, and I still can't get it right. I am wondering if the rear mech may need changing.
  • First.Aspect
    First.Aspect Posts: 17,270
    Could be the mech hanger is a bit out.

    The rear deraileur could have developed a bit of play. Or the jockey wheels.

    Is the cassette (and chain) new or getting on a bit? You are, after all, talking about the most frequently used sprockets.

    Finally, anyone taken a look at the ratchet system in the level itself? Could need some attention.

    Failing that, you'll need a new bike.
  • crikey
    crikey Posts: 362
    If the super spanner monkeys can't sort it out, take it somewhere else.
    It's not rocket science, it's a bike.
  • lesfirth
    lesfirth Posts: 1,382
    The following is taken from a reply by the campag guru Graeme from Velotec in Dec 13

    Gear cable the wrong side of the pinch bolt on the RD.
    The gear cable should run straight across the back of the pinch bolt as you look at it from the right hand (gear) side of the bike. It should not be wrapped around the pinch bolt and it should be held between the flat tab of the washer under the pinch bolt and the RD body - the tab at 90 degrees is not used to trap the cable, it's used to stop the washer turning as you tighten the pinch bolt.
    Normally this will just give you ropey shifting and a missing sprocket as the movement of gear to cable recovery in the lever relationship is changed if the cable is the wrong side of the pinch bolt or incorrectly pinched. However, it's just possible, given all the variables including the "floating" top jockey wheel and a bit of wear and tear, to get acceptable shifting to somewhere around the middle of the cassette, then a sprocket missed, then acceptable shifting across the rest of the cassette. You have to try quite hard, but it can be done :-)

    This is just part of his reply to a similar question to yours. It fixed my problem. If this bit does not fix yours it is worth doing a bit of searching for the rest of his post.
  • on-yer-bike
    on-yer-bike Posts: 2,974
    Same problem with Athena. Shifting inconsistent on middle sprockets. New cable, hanger aligned, new chain. Can only think that the sprockets are worn although they aren't slipping. I have had problems with Record where the hanger hasnt been stiff enough but this is a steel frame with built in hanger.
    Pegoretti
    Colnago
    Cervelo
    Campagnolo
  • dabber
    dabber Posts: 1,982
    lesfirth wrote:
    The following is taken from a reply by the campag guru Graeme from Velotec in Dec 13

    Gear cable the wrong side of the pinch bolt on the RD.
    The gear cable should run straight across the back of the pinch bolt as you look at it from the right hand (gear) side of the bike. It should not be wrapped around the pinch bolt and it should be held between the flat tab of the washer under the pinch bolt and the RD body - the tab at 90 degrees is not used to trap the cable, it's used to stop the washer turning as you tighten the pinch bolt.
    Normally this will just give you ropey shifting and a missing sprocket as the movement of gear to cable recovery in the lever relationship is changed if the cable is the wrong side of the pinch bolt or incorrectly pinched. However, it's just possible, given all the variables including the "floating" top jockey wheel and a bit of wear and tear, to get acceptable shifting to somewhere around the middle of the cassette, then a sprocket missed, then acceptable shifting across the rest of the cassette. You have to try quite hard, but it can be done :-)

    This is just part of his reply to a similar question to yours. It fixed my problem. If this bit does not fix yours it is worth doing a bit of searching for the rest of his post.

    I had a similar problem after refitting RD and cable. I'd attached the cable wrongly as referred to in Velotec's earlier posting. Once I corrected that, all was good.
    “You may think that; I couldn’t possibly comment!”

    Wilier Cento Uno SR/Wilier Mortirolo/Specialized Roubaix Comp/Kona Hei Hei/Calibre Bossnut
  • paul64
    paul64 Posts: 278
    Guessing that no one had the issue i had recently when building up my Veloce steed and having mid cassette shifting issues. Kept staring at the cassette and realised after a few minutes that the spacers were not all the same thickness. All okay once the spacing between sprockets was even