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Campagnolo Xenon shifter.Too many downshifts.

weedy1weedy1 Posts: 143
edited September 2014 in Workshop
Xenon 10 speed circa 2010.
When I press the down shift button in 'mid range' gear, I drop 3 or 4 cogs in one go !
Does not happen so much at the extremes (big or little cogs) and is annoying me.
Started intermittently and i thought i wasn't depressing the button quickly enough but it has happened when I've slamed the button down quickly.
Button release is fine and it pops up right away.

Any idea what causes this and how to fix it?

or shall I splurge on some new Veloce and bar tape ?

help very welcome.

Posts

  • wilky27wilky27 Posts: 200
    Hi, did you fix this issue? I'm having exactly same problem with my xenon shifters.

    Ta.
  • epirbepirb Posts: 16
    I have the exact same issue with the Centaur 10 speed Red & Black Carbon version, Power Shift. Only 3000 odd dry miles.
    I've flushed it out with gt85 which didn't seem to make much difference.
    On a thumb press it sounds like whatever "pawl" locks the thumb button is skipping over the teeth. So fearing either worn teeth or something sticking. The button release does seem to pop up fine though.
    Any ideas?
  • rolf_frolf_f Posts: 16,015
    epirb wrote:
    I have the exact same issue with the Centaur 10 speed Red & Black Carbon version, Power Shift. Only 3000 odd dry miles.
    I've flushed it out with gt85 which didn't seem to make much difference.
    On a thumb press it sounds like whatever "pawl" locks the thumb button is skipping over the teeth. So fearing either worn teeth or something sticking. The button release does seem to pop up fine though.
    Any ideas?

    You definitely don't have exactly the same issues even if the symptoms are the same! Your shifters are completely different to those of the previous two posters - your downshift is just a button which only drops one gear at a time. They have the Ultrashift levers which can drop one to 3 or 4 at a time.

    To OP - I think I would disconnect the cables and pull them out and see if the shifter behaves properly without them. If it does, then you are probably just needing new cables and maybe outers. Or it might just be dirty.

    You will do multi shifts if you 'slam the button down quickly' - it should only need a fairly gentle but firm push if you want to change a single gear.
    Faster than a tent.......
  • epirbepirb Posts: 16
    Thanks for the reply.
    When they mentioned buttons I assumed it was powershift as I thought ultrashift was more of a thumb lever and was supposed to allow multi down shifts anyway.
    Also, I've resurrected this thread as I thought it was the most relative to my issues. I'd assume the OP has it sorted by now.

    My multi shifts occur regardless of how fast or hard a push the button.
  • rolf_frolf_f Posts: 16,015
    Didn't spot it was a resurrection...... Don't know anything about Powershift but yours does sound somewhat unhealthy if it is doing multi downshifts. Could try Velotech Engineering who are Campag specialists. They certainly can service Ultrashift mechs but whether Powershift is similarly repairable I don't know.
    Faster than a tent.......
  • ratsbeyfusratsbeyfus Posts: 2,841
    I had Xenon shifters on an old bike and they were awful. Shifters made of very weak plastic, and LHS one broke. The flexy plastic shifter behind the brake lever put tension in the spring, whereas the stronger thumb shifter released tension which is the wrong way round and bad design IMO. Upgraded to Veloce.


    I had one of them red bikes but I don't any more. Sad face.

    @ratsbey
  • epirbepirb Posts: 16
    yeah perhaps I should have started a new topic. I have centaur which have been great, until now.
    Was hoping someone else had experienced and fixed the same issue.
  • wilky27wilky27 Posts: 200
    I know this is old but I had the same issue with my Centaur levers recently. The ratched had come loose and was skipping down the bottom sprocket if I held my thumb on the downshift. I sent them back to campag as they have a 2 year warranty. I did this through Ribble Cycles where I bought them from. They just replaced the shifter body and it's fully functional again.
  • I discovered the answer to this in the week.
    I have some 2007 Veloce shifters which have the same symptoms. In most Campag Ergos its a symptom of the G spring dying. You spent a couple of quid on the spring and 10 minutes swapping it. Easy thinks I.
    Nope . 07 Veloces have the same button as the Xenon.
    Changing UP requires pushing it and the chain moves down the block by the way. 1st to 10th.
    Anyway, I digress. In these models you do not just buy the upshift button, you buy the body. You don't get the brake lever or cables or anything and you pay 60 quid for the privilege! For 75 you can get a new set of Veloces from this year.
    Have look on you tube, searching for Campag Xenon or maybe Escape. Its easy to pull them apart and see but I bet you find that the edge of the tooth, that is really the other end of the upshift button, has flattened off and isn't catching on the pawl of the bit it should. Plastic against plastic I suppose.
    You can help the shift by holding the down shift lever as you hit that button and can sort of stop it going too far. I can manage to keep it to only moving to sprockets not the one I want and within a turn of the pedals I can hoist the chain back to where it should be.
  • keezxkeezx Posts: 1,319
    I posess 5 pairs of pre-2006 Chorus and Veloce 9 and 10 speed Ergopowers (old mechanism) and I will never give them away or sell them, except when I'm too old to ride anymore.
    The never give trouble but sometimes they get damaged and spare parts are a blessing to have.
    I will never buy anything from the Escape range.
  • beardwithabikebeardwithabike Posts: 195
    epirb said:

    I have the exact same issue with the Centaur 10 speed Red & Black Carbon version, Power Shift. Only 3000 odd dry miles.

    I've flushed it out with gt85 which didn't seem to make much difference.

    On a thumb press it sounds like whatever "pawl" locks the thumb button is skipping over the teeth. So fearing either worn teeth or something sticking. The button release does seem to pop up fine though.

    Any ideas?

    Hey epirb - Did you ever get to the bottom of your issue? I’ve got the same shifters as you and have now encountered this problem.

    Comments appreciated!
  • mattsccmmattsccm Posts: 408
    That pawl will be worn. Plastic they are on the cheaper Ergos. I reshaped one withe lighter and a file. Bought scrap higher level ones and canibalised them eventually.
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