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  1. #1
    Senior Member dynne's Avatar
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    1981 Trek 613, Bianchi Ibex, Bianchi Fixed, Schwinn Tempo, nothing that would get stolen (sigh).
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    Correct front derailleur/chain length for vintage touring rebuild?

    I'm rebuilding an old touring frame, and I've got most everything good to go - except for the front derailleur. I'll need one that will attach onto the 28.6 tube and isn't clamp-on. I assumed that since the front derailleur will be running friction, whatever road triple I had sitting around would work. But, as we all know, nothing with bikes is ever this simple.

    Relevant info:
    Running Ultegra road triple (52-42-38?) with 11-32 9 speed cassette.
    Using Dura-Ace 3x9 barcons.
    Rear derailleur is Shimano LX (was advised would be better than 105)

    The problem: Need RD that doesn't take clamp-on, 28.6 seems an odd size. The Tiagra road triple I hoped to use looks to be too wide.

    What would be the best choice for a front derailleur? Shim the Tiagra? Use a mountain triple?

    Additionally, once I've got that one up, how long should I trim the chain for? I don't foresee running 52-32, so is the typical rule of chain length measurement out the window?

    I apologize if this has been covered in other threads, but since I had two problems simultaneously, I figured I would consult the experts directly. Thanks so much for your time.

    Can't wait to get this baby on the road.
    Can't stop this ride.

  2. #2
    cab horn
    Join Date
    Jun 2004
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    1987 Bianchi Campione
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    For the FD.

    Don't bother finding the right clamp size if it's a pain in the ass. Get the braze on version and a braze-on adapter. FD-6503 is what you want.

    Chain length should be sized using the big/big + next closest link method. It doesn't matter if you don't use the 52 + 32 combo. If you cut the chain for something smaller, your derailleur blows up.
    Mes compaingnons cui j'amoie et cui j'aim,... Me di, chanson.

  3. #3
    Senior Member
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    http://www.parktool.com/blog/repair-...-length-sizing

    SIMPLE EQUATION: L = 2 (C) + (F/4 + R/4 + 1)

    L = Chain length in inches. Round the final result to closest whole inch figure.
    C = Chain stay length in inches, measure to closest 1/8”.
    F= Number of teeth on largest front chainring.
    R= Number of teeth on largest rear cog.

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