Brand new Ultegra low gears slipping/jumping

Bordersroadie Posts: 1,052
edited December 2011 in Workshop
I bought a brand new Cube with triple Ultegra. First time "out" today, on the turbo.

On the granny ring and the biggest three rear sprockets, three problems.

1. Lowest gear causes the derailleur to make skipping noises as it "wags" back and forth although the chain stays on the cog. Some adjustment needed though maybe.

2. Changing from biggest rear cog to the next smallest, it jumps two, not one, every time.

3. I can only get into the second biggest rear cog when changing from the next smaller one, not the other way (see 2 above) and once in that gear the chain jumps intermittently and randomly to the smaller cog.

Not impressed, since getting a triple was specifically to have quality gearchanges in these lower ratios.

I'm assuming some LBS adjustment is needed, but is this normal on a newly-delivered CRC bike?


  • Wirral_paul
    Wirral_paul Posts: 2,476
    Cables gradually stretch from new. Have you tried tightening the barrel adjuster on the back of the derailleur??
  • nicklouse
    nicklouse Posts: 50,675
    1 sounds normal
    2and3 sounds like cable tension needs adding.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Thanks for the comments, guys, I'll investigate further.

    I should have said that in point 1 the gear actually slips when the derailleur skips, so definitely not normal operation - I wouldn't fancy tackling Hardknott with that happening every other pedal revolution. . .
  • jameses
    jameses Posts: 653
    I've bought two new bikes in the past few years; neither had the rear mech properly set up when I got them (from Evans and The Bike Factory - LBS next time!)
    Should be a fairly simple matter to fix - sounds like you may need to fiddle with one of the positioning screws on the mech to get it to sit in the correct position over your lowest gear. Once that is done, adjust the cable tension using the barrel adjuster to smooth out the shifts. As mentioned above, the cable will stretch from new, so you will probably need to play with the cable tension again in a few weeks.
  • diy
    diy Posts: 6,473
    sounds like a bent tooth or a stiff link on the chain.
  • craker
    craker Posts: 1,739
    I had an overlong chain on my roadie at one point - it would skip under load because the mech. couldn't keep enough tension on the chain.

    take off two links, runs a treat now.
  • keef66
    keef66 Posts: 13,123
    It's just the rear mech cable tension needing a tweak at the barrel adjuster.
  • You're all bloody brilliant! Thanks for your help, all. Great Youtube link.