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  1. #1
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    IRO crankset + bottom bracket chainline problems

    Hi all,

    I have a 2005 Bianchi Pista. I use it every day as my main transportation so I like keeping it in tip top shape. My old cranks and bottom bracket were worn out (the cranks would slowly loosen over time and work out the bolt), and also the rear hub went bad, so I just bought a new IRO rear wheel, IRO 110mm bottom bracket, new IRO 165mm cranks, and a new KMC Z410 1/8" chain.. According to IRO's website, the 110mm BB + IRO crank combination gives a 42mm chainline.

    I put the parts on my bike today and I measure a 47.5mm chainline on the front and 41.7 on the back. Why is my front chainline over half a centimeter off? The bottom bracket is installed the right direction, and everything is tightened down properly. The cranks came with a 46t chainring which I haven't touched.

    I am not experienced dealing with chainline issues... what's my best course of action? Replace the bottom bracket? Contact IRO? (they do say the cranks + bottom bracket combo should give a 42mm chainline...)

    Thanks
    Ben

  2. #2
    Mo' Senior SSSasky's Avatar
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    1984 Norco Monterey SL (Ishwata 3X butted), matte black, 42-15 fixed
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    Move the chainring to the inside of the crankarms spider.



    (Sounds like you've got them on the outside). I've had that crankset for a couple years, several BBs. Always 42mm chainline with 110BB, with chainring on the inside.

  3. #3
    Mo' Senior SSSasky's Avatar
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    Oh yeah: if that doesn't work, take pictures and post them.

  4. #4
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    I would do that but the chainring is already on the inside.

    Here are some pics. I can ride the bike but the chain is really noisy.











    Thanks!

  5. #5
    out of shape
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    good lord, that's a lot of electrical tape.

  6. #6
    jon bon stovie
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    any luck figuring it out yet?

  7. #7
    Junior Member Savic's Avatar
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    Quote Originally Posted by chase. View Post
    good lord, that's a lot of electrical tape.
    Why the tape?

  8. #8
    Stinky McStinkface exfreewheeler's Avatar
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    I've seen people tell others to flip the chainring/cog.

    I guess some manufacturers make the them with the teeth offset, or suh'm?
    Because, yeah... uh huh! Umm, yeah!

  9. #9
    THIS SPACE FOR RENT
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    Very weird. Maybe pull the cranks and confirm that the BB is actually 110.

    Also, I've said this 1,000,000 times, but when you have a problem with IRO stuff or a question about their products, CALL TONY. People act like this board is the IRO support forum.
    "I don't buy new frames, it just encourages them."

    -T.G.

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