Campag Centaur Front Mech issues..

Compton77
Compton77 Posts: 139
edited June 2008 in Workshop
I've had a quick search through previous posts and i'm sure that this has been broached before, so sorry if i'm repeating a previous subject. This morning on the way to work the front deraileur wouldn't change from big to small chainring, the bike is due it's first service (next week) but i've got to get through this week! Any ideas how i might be able to get rid (adjusting the screws??) When i'm hitting the thumb trigger it makes a noise similar to the chain rubbing, i keep the pedals turning hoping for the shift(!) and in the end flick the up paddle to stay in the big ring. Not ideal.

Cheers
Matt
Cervelo RS

Comments

  • Mystique
    Mystique Posts: 342
    Sounds like the cable's stretched - not uncommon on a new bike. There's generally no easy adjustment as there would be for the rear (at least, that's how it is on my Veloce setup) so it would be a matter of re-fixing the cable at the derailleur itself.

    At least it'll give them something to so at the service :wink:
  • caw35slr
    caw35slr Posts: 439
    Surely shifting big-to-small with the thumb button releases cable, so either something is preventing the mech spring from moving the mech inwards, or something is not allowing the cable to be released fully.

    Presuming that the limit screws are set right, I'd expect a stretched cable to cause you no problems when shifting with the thumb (i.e. the mech should return to its resting position against the lower limit screw). Indeed, a stretched cable would be more likely to cause difficulty when shifting in the other direction.
  • Mystique
    Mystique Posts: 342
    Very true.

    Note to self: Engage brain before typing... :oops:
  • caw35slr
    caw35slr Posts: 439
    LOL, I had to re-read what I wrote to make sure I wasn't the one with the over-heated cranium... ;-)
  • Compton77
    Compton77 Posts: 139
    riding home from work last night it got even worse, on the final half mile or so i was accelerating hard in the small ring hit the shifter to move to the big ring.............chain fell off, luckily i was carrying enough speed i was able to pull over safely and get things re-connected. Not inspiring much confidence..
    Cervelo RS
  • psychle
    psychle Posts: 83
    :? Confused now. Is the problem big-to-small or small-to-big? Or is it both now?

    I've always had problems going from big ring to small ring when putting the pressure on (which is normally when you have to switch from big to small), with my Campag Veloce equipment. I've just put it down to a less than perfect design, specifically the return spring lacking power. I'd still be interested to hear of any suggestions which might improve the situation.

    "Like a pig towing a cart-load of sausages - I draw my own conclusions"
  • Compton77
    Compton77 Posts: 139
    yeah good point Psychle! I'll give you some background, a couple of weekends ago i was riding down to Brighton was round Reigate way and flicked to move into the big ring, chain came off. Got oily hands but hooked the chain back on, behaved fine then all the way to Brighton. Next ride it wouldn't move from the big to the small, after a few attempts it finally moved, then last night i tried to move it into the big ring and the chain came off again!! Not happy. The mechanic from my LBS is on holiday this week, so can't look at it until Monday..grrr..

    So the issue now seems to be changing at the front, full stop..
    Cervelo RS
  • over-the-hill
    over-the-hill Posts: 144
    Compton77 wrote:
    yeah good point Psychle! I'll give you some background, a couple of weekends ago i was riding down to Brighton was round Reigate way and flicked to move into the big ring, chain came off. Got oily hands but hooked the chain back on, behaved fine then all the way to Brighton. Next ride it wouldn't move from the big to the small, after a few attempts it finally moved, then last night i tried to move it into the big ring and the chain came off again!! Not happy. The mechanic from my LBS is on holiday this week, so can't look at it until Monday..grrr..

    So the issue now seems to be changing at the front, full stop..

    Same bike, same problem with the chain going over the big ring. I recently posted on the topic. i hope there isn't some frame alignment problem...
  • Compton77
    Compton77 Posts: 139
    Same bike, same problem with the chain going over the big ring. I recently posted on the topic. i hope there isn't some frame alignment problem...

    Doesn't sound good, so your having the same issues? I spoke to my LBS today and I mentioned maybe adjusting the limit screws, they said they wouldn't advise me fiddling with it and to bring it in to let one of the other guys have a look. When you say same bike do you mean Centaur as well??
    Cervelo RS
  • Compton77
    Compton77 Posts: 139
    somehow managed to put my text as a quote, but i'm sure you get the idea..!
    Cervelo RS
  • caw35slr
    caw35slr Posts: 439
    Chain falling off big ring? Try adjusting your upper limit screw:

    http://www.parktool.com/repair/readhowto.asp?id=75
  • over-the-hill
    over-the-hill Posts: 144
    Compton77 wrote:
    Same bike, same problem with the chain going over the big ring. I recently posted on the topic. i hope there isn't some frame alignment problem...

    Doesn't sound good, so your having the same issues? I spoke to my LBS today and I mentioned maybe adjusting the limit screws, they said they wouldn't advise me fiddling with it and to bring it in to let one of the other guys have a look. When you say same bike do you mean Centaur as well??

    Yes, Centaur and its had its first service. They won't want you fiddling before the 1st service. I think sometimes the bike can be OK on the stand but out when you ride it. So it pays to be able to tweak things out on the road. I now realise it isn't very complicated its all about screws that limit the movement of the mech and cable tension. That said its worrying when it keeps happening. Let me know how you get on after the service.
  • caw35slr
    caw35slr Posts: 439
    Guys, over-the-hill is absolutely correct: adjusting limit screws if a piece of cake. 30 seconds of adjustment will improve your life no end. :-)

    Read the Park Tools link above or, better yet, acquire a decent workshop manual like Zinn and the Art of Road Bike Maintenance and follow its instructions.

    Do your own work - you'll end up with a better, more reliable bike. What's more, roadside problems will become something to fix as opposed to something that wrecks your day.

    Enjoy!
  • Compton77
    Compton77 Posts: 139
    Just a quick update, back from the LBS now and all is well, shifting is nice and crisp and the steerer tube has been cut. My issues with gear changing was down to the cables stretching supposedly. All i've got to do now is wait for my stem to come in and i'm complete, oh apart from the Garmin 705, which is to be ordered tomorrow..

    Over-the-hill - you still having issues with your Centaur??
    Cervelo RS
  • over-the-hill
    over-the-hill Posts: 144
    Compton77 wrote:
    .

    Over-the-hill - you still having issues with your Centaur??

    No, a quarter turn in of the outside limit screw fixed it but I can only just make the final click on the lever to avoid chain rub in the highest gears (large front small back).
    The problem now is the middle gears at the rear are noisy. Not sure if it is possible to get it perfect. The main thing is that the chain no longer falls off.

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