Perfect adjustment of Campagnolo FD...

neeb
neeb Posts: 4,470
edited July 2014 in Workshop
For some reason perfect adjustment of the Chorus / Record / SR 11sp FD always eludes me, and if I do manage it it seems to be down to chance.

If I follow the instructions to the letter and adjust the tension so that three clicks will just manage to shift the chain from the small ring to the big ring while the chain is on the largest rear sprocket, and then bring the outer limit adjuster flush, then half the time when in use it will throw the chain off the outer ring (i.e. it is shifting too far).

The way the FD works seems to be incredibly sensitive to alignment. I have tried getting the inside surface of the outer part of the cage completely parallel with the chainrings as in the instructions, but I'm not actually convinced that this is the ideal alignment as the times I have had it working well seem to have been when I haven't done this...

Comments

  • cycleclinic
    cycleclinic Posts: 6,865
    set the inner limit screw when in small big so the cage just clears the change. Move the shifter and outer limit screw. I have not found Campagnolo FD to be any more sensitive to cage alignment than any other brand. If it is not working right then you have not completed a step properly I know that does not help much but with see the bike it is difficult to be more precise.
    http://www.thecycleclinic.co.uk -wheel building and other stuff.
  • g00se
    g00se Posts: 2,221
    The magic bullets I found were:

    1. Get the outside place flush
    2. When pushed out, have the outside plate clear the large chain ring by a bit over 1 mm.
    3. Set the inner limit so that on small-front/large-rear, the chain just clears the inner place.
    4. Set the outer limit so that the plastic piece on the inside tip of the cage's outer plate is 0.5mm from the chain
    5. THIS: Tension the cable so that as soon as you start moving the finger gear lever, the mech starts to move.
  • neeb
    neeb Posts: 4,470
    Thanks both, I'll continue fiddling and report back...
  • on-yer-bike
    on-yer-bike Posts: 2,974
    Make sure the cage is parallel to the big ring before attaching cable
    It is three clicks when in the largest sprocket but I have found that this is not enough tension to make it shift down to the small ring properly – the chain does not engage especially when using the smallest half of the cassette. Once the chain is on the large ring and the smallest sprocket the cage should be about 1mm from the chain. Thee limit screw should feel lose so just tighten it so it nearly touches the stop and prevents a 4th click. I find the lower edge of the cage should be 3mm away from the big ring. If its too close shifting is less smooth. Im surprised at how tight the front mech cable has to be.
    Pegoretti
    Colnago
    Cervelo
    Campagnolo
  • neeb
    neeb Posts: 4,470
    Well, I fiddled with it again and it is now working perfectly. There were two problems I think:

    - The outer plate of the cage was not quite parallel with the chain rings. I have been confused by this in the past as I am sure there was a time when the instructions talked about getting the inner plate of the cage parallel with the rings, and as the inner side of the inner plate is a funny sculpted shape this is rather ambiguous.. I've found now that if you are trying to get the inner side of the outer plate parallel, the best way to see it is to operate the shifter without spinning the crank so the chain remains on the inner ring but the dérailleur is far enough out for you to line up the inner side of the outer plate by eye from above..

    - When setting the cable tension and the limit screw for the outer position, it's best to go for having the inner side of the outer plate (or the plastic insert) just brushing the chain when it is on small sprocket / big ring, rather than following the Campagnolo instructions which say that you should have the inner side of the inner plate just brushing the chain when on big sprocket / big ring... The latter ends up with the outer setting being a little further out and can lead to the chain being thrown off.

    Oh - and I also raised the dérailleur a little to get the chain nearer 2-3mm from the teeth of the outer ring rather than 1mm. It does indeed seem to work better if it's not too close.