Shifting Delay

dawebbo
dawebbo Posts: 456
edited March 2011 in Workshop
I'm getting a 1-2s delay when shifting to a smaller sprocket if on the big ring

Wondering if anyone else has experienced this, and any thoughts on how to fix... any suggestions welcome

Notes:
Only happens in the big ring
Shifting to larger sprockets is fine
Brand new veloce 2011 gruppo
Brand new cableset, no acute angles in outers etc.
indexing seems ok, no rubbing, clicking etc and can get full range of gears.
Chain-length as advised by instructions, i.e. jockey wheel thing is perpendicular to floor when in big ring & sprocket
No known of knocks to the hangar (from what I can tell) it appears straight.

Comments

  • John.T
    John.T Posts: 3,698
    Chain-length as advised by instructions, i.e. jockey wheel thing is perpendicular to floor when in big ring & sprocket
    That should be 'big ring and small sprocket'. This may have something to do with it.
    Otherwise back the indexing off a notch or two. It may not be quite right.
    My Fleet.
  • dawebbo
    dawebbo Posts: 456
    You're right. Not by the bike when I typed that... it is set up big ring, small sprocket.

    I'll try the indexing again tonight.

    Cheers
  • keef66
    keef66 Posts: 13,123
    "Chain-length as advised by instructions, i.e. jockey wheel thing is perpendicular to floor when in big ring & sprocket "

    I was assuming that was a typo and meant small sprocket. Big - big and the pulleys can sometimes be nearly horizontal.

    Movement in that direction is caused by releasing cable tension and allowing the derailleur return spring to push the cage across. So it's either as JT suggests that the indexing is out a tiny bit and so it's not releasing quite enough cable to precipitate the shift instantly, or there is some drag in the cable operation somewhere. Might even be in the shifter itself. Weird it happens in the big ring only; that suggests that the greater chain tension is in some way responsible for exaggerating the sluggish movement of the derailleur.
  • dawebbo
    dawebbo Posts: 456
    Thanks Keef - yes typo/bad memory ;-)

    The greater chain tension point makes sense to me - the more I think about it the more I'm convinced it's the indexing. The other things you'd expect to affect changes when in the small ring too.

    thx
  • John.T
    John.T Posts: 3,698
    Minor indexing problems do tend to show up more on the big ring. Not sure why but could be due to the higher chain tension or the different position of the top jockey wheel. A 'sticky' cable in the rear loop can also cause problems but I find this affects the bigger sprockets more.
    My Fleet.

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