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  1. #1
    BeaverTerror Yan's Avatar
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    Front Derailleur Capacity

    I'm building a 3x9 speed touring bike with 50-38-24 chainrings. The people in the touring forums recommend the 9 speed Tiagra front derailleur, because it has a comparatively wide cage that minimized chain rub.

    My setup has a 26 tooth difference between the highest and lowest chainrings. Shimano's tech docs say that the Tiagra front derailleur has a 20 tooth capacity. Will it still work, and if not, what is a better front derailleur?
    Yan

    2013 True North custom touring; 2010 Novara Randonee; 2009 Unicycle.com Club 24"; 1989 Miele Tivoli; 1979 Colnago Sport

  2. #2
    Great State of Varmint Panthers007's Avatar
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    Shimano's Max Tooth Diff. crud is wildly inaccurate. It will likely work fine - but I never did this with a Tiagra. Done it with others in going over Shimano's stated MAX. No problems yet.
    How do you keep an idiot in suspense?

  3. #3
    AEO
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    it should work fine, I have a 105 double FD pushing a 26-36-46 and there's plenty of space left in the cage for a 50-38-24
    Food for thought: if you aren't dead by 2050, you and your entire family will be within a few years from starvation. Now that is a cruel gift to leave for your offspring. ;)
    http://sanfrancisco.ibtimes.com/arti...ger-photos.htm

  4. #4
    * adriano's Avatar
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    do you think i could push a ten speed double front derailleur between 18 teeth?

  5. #5
    AEO
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    between two chainrings or three?

    between three, you can exceed 20 teeth provided you don't go beyond 14~16T difference between each cog.
    between two, the shifting can be really horrid simply due to the teeth difference.
    Food for thought: if you aren't dead by 2050, you and your entire family will be within a few years from starvation. Now that is a cruel gift to leave for your offspring. ;)
    http://sanfrancisco.ibtimes.com/arti...ger-photos.htm

  6. #6
    Senior Member
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    A 24t chainring seems awfully small.

  7. #7
    Galveston County Texas 10 Wheels's Avatar
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    Mine works Fine.
    50-39-24, with a 14-25 cassette.
    [SIZE=1][B]What I like about Texas[/B]
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  8. #8
    Senior Member demoncyclist's Avatar
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    For loaded touring, a 24T granny ring makes sense.
    DEMON

    Satanic Mechanic
    STAR 3 Spinning Instructor

    2011 Lynskey Sportive (Shimano Ultegra 10s)
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