Ultegra di2 10sp nasty noise

tonyhogg Posts: 115
edited May 2014 in Workshop
My bike has started making this really rough sounding noise, most noticeable when in the big ring middle ish of the cassette, just recently changed from the standard chain to a kmc chain which was fine for the first few rides nice and quiet. Entire drivetrain has been cleaned and lubed, really can't think what it could be?

Seems to change gear fine no problems, it's a little less noisy in the small ring but still noticeable, totally unbearable in the big ring, amazes me how di2 can be tuned and working perfectly then turns to this, surely can't need a new cassette yet? Only got 2000ish miles on it.



  • 47p2
    47p2 Posts: 329
    Are you sure you fitted the correct width chain? it looks rather wide in the video
  • tonyhogg
    tonyhogg Posts: 115
    That's crossed my mind, I'll definitely be changing my cassette and chain to match perfectly. Strange because it worked so smooth and quiet at first???
  • DiscoBoy
    DiscoBoy Posts: 905
    Which KMC chain is it, then?
    Red bikes are the fastest.
  • tonyhogg
    tonyhogg Posts: 115
    It's a 10sp chain, you'd think a qualified mechanic could fit the correct chain wouldn't you? My thinking is this newer chain has gradually worn the old cassette since fitting and caused this horrendous noisy drivetrain, it's pretty quiet in the last smallest two sprockets when in the big ring going flat out, I've pushed my avg up a bit on starva anyway lol.
  • tonyhogg
    tonyhogg Posts: 115
    Had the mech hangar re-aligned from my lbs and it's still not sorted the dodgy sounding drivetrain, is it worth going into adjustment mode on the di2 and messing around? Big ring and little ring, middle ish of the cassette seems the worst.

    I'm at a loss to guess what could be causing it? Had a close look at the angle of the chain and it appears to be slighting rubbing other cogs on the cassette in the problem gears.
  • tuneskyline
    tuneskyline Posts: 370
    You could have a small mouse in your down-tube.
  • Ben6899
    Ben6899 Posts: 9,686
    For me, that's what a mis-indexed mechanical setup sounds like, but I don't have any experience with electronic kit... how is indexing done?

    I think a wear-mismatched chain/cassette combination would skip under load more than sounding like dogshit.

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  • Bar Shaker
    Bar Shaker Posts: 2,313
    To re-index it, put the bike into a mid cassette cog. Press the button on the controller and a solid red light will come on.

    Press the front shift (change down) button until the chain is contacting the bigger cog next to it. Then press the shift up paddle 4 times. Each button press moves the DR 0.2mm.

    The best way to do this is when riding on a quiet flat road.

    You should never need to do it again unless you change cassettes or similar.
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