campagnolo shifting spring not strong enough

brearley
brearley Posts: 165
edited September 2013 in Workshop
Hello All,

after having a cable stuck in my shifter I had to take the mechanism apart, after getting it all sorted I put the shifter back together and put a turn on the spring before seating it back in its hole to get the tension on the spring.
after setting everything up the gears shift up fine but to get them to move down i have to physically drop the mech back down. Is this a case of the rear mech being crap and not dropping down when not under tension or is this a shifter problem. I'm hoping its the former as I have a new rear mech coming in the post anyway.
if it's the spring then how do I fix it?

Comments

  • jimwin
    jimwin Posts: 208
    Assuming the shifter was ok before you took it apart, it looks like this is re-assembly time.

    Check here for a rebuild...

    http://www.campyonly.com/howto/ergo_rebuild.html

    and good luck.

    BTW - I've done a rebuild in the past and it can be a bit tricky without the right tools and a bit of ingenuity.
  • I'll have a go at rebuilding it again however I only took out two parts (the spring and the black bit that retains the cable)
    having put the cable holder back in which is under no tension and then winding the spring so it's under tension everything else should be as it was before when it was working ok.
    Honestly this has been a bigger PITA than I imagined when I starting building my training bike, a 5 minute job of putting cables in and tightening up has taken hours of time and still isn't bloody working.
  • jimwin
    jimwin Posts: 208
    If you take the shifting cable out so the rear-mech is free and remove the chain, you can manually push the mech by hand. It should be a firm push with an immediate drop back when you release the pressure. The point here is to make sure the rear-mech is moving freely and the return spring is fully working and not dragging at any point. If the return force is not consistent over the full range of the mech, the chunky spring may be jamming internally so check how the spring moves under the mech cage with a small inspection mirror. If there's a problem in the return force consistency and smoothness, it probably means you need a new rear-mech.