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  1. #1
    26r grudgemonkey's Avatar
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    Triple front derailleur with a Double/Compact Crankset?

    Will a triple front derailleur work with a compact crankset or do I need to install a different derailleur?

  2. #2
    Low car diet JiveTurkey's Avatar
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    The only difference I see between a triple and a double front derailleur is the extended inner plate of the former, which assists shifting between the inner and middle chainrings. As long as the limit screws can be adjusted properly, I don't see why it would not work on a double setup.

    Since standard double FDs are routinely used on compact cranks, I also don't see why a triple FD would not work on a compact (might it even work better than a standard due to that extended inner plate to aid in the 14T or 16T jump?).
    Quote Originally Posted by slopvehicle View Post
    Not wearing a helmet makes me more aware of my surroundings. I find myself anticipating the hardness of concrete 50 or 100 feet in front of me, it's almost a zen-like connection between my face and the pavement.

  3. #3
    Small Member maddmaxx's Avatar
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    I have never tried this but.........it makes me a bit nervous. Triple front derailleurs work because the zigs and zags of the inner cage plate engage the chain at different "center" distances depending on how high the chain is in the derailleur. When a triple is setup to use as a double, the lowest zig is never engaged because of the height of the inner chainwheel. On a full 34/50 compact, it might be that the inner chainwheel is small enough to let the chain start into that lower zig as if there were a granny there........but then as the chain is pushed out to the larger chainwheel, it must both move onto the middle zag of the derailleur and then up on to the top zig. All of those zigs and zags are potential trouble spots.

    I'm not going to say it won't work but since normal double derailleurs sometimes have problems with certain compact cranks this seems to be asking for trouble. If it works, let us know.

  4. #4
    Fred-ish rogerstg's Avatar
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    I have a triple 105 brifter shifting a Sora double fd on a compact crank. It shifts perfectly - I used the first and second positions.

  5. #5
    Senior Member
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    Bump.

    I just tried this this week. Went from ultegra 6503 to 2009 rival. It didn't work for me. I couldn't get the front derailleur to support the chain when downshifting so it dropped the chain a lot. I had adjusted the front so that it was just above the top ring, straight, and the low was set so that the chain would rub if it went any tighter.

    I should get my rival front in later this week and I'll post that it worked so you all know I'm not inept...

    Obviously, going shimano->sram while going triple->double is a mitigating factor, but I thought I'd point out the experience.

    It seemed like the contour of the front derailleur was a problem. The chain, on the small ring, fell so that it was on a contour of the inner plate.

    Upshifting seemed to work great.

  6. #6
    Member musicociclista's Avatar
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    I replaced a 105 triple crankset with a 53-39 double and the triple front derailleur have performed flawlessly. You just have to align it with the double's big ring. Even the triple shifter works great, as I understand now days are compatible either way.

  7. #7
    Senior Member
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    Posted in another thread as well recently. I just replaced my stock triple crank with a tiagra double. The Sora triple shifter and triple front derailleur work just fine.

  8. #8
    Senior Member bon_gabs's Avatar
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    I love this forum,,,

  9. #9
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    Quote Originally Posted by grudgemonkey View Post
    Will a triple front derailleur work with a compact crankset or do I need to install a different derailleur?
    I couldn't make it work reliably.

    Try your front derailleur (they vary) on your frame (stay length varies) and see how it works. Either it will be good enough (you don't need to spend any money) or not.
    Last edited by Drew Eckhardt; 11-19-11 at 09:02 PM.

  10. #10
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    Quote Originally Posted by JiveTurkey View Post
    The only difference I see between a triple and a double front derailleur is the extended inner plate of the former, which assists shifting between the inner and middle chainrings. As long as the limit screws can be adjusted properly, I don't see why it would not work on a double setup.
    Nope.

    The geometry is different to accommodate the big ring being farther outboard on the triple crank.

    The cage is often wider too.

    Between the two it's sometimes not possible to get reliable shifting to the big ring without sometimes over-shifting onto the crank arm.

    Since standard double FDs are routinely used on compact cranks, I also don't see why a triple FD would not work on a compact (might it even work better than a standard due to that extended inner plate to aid in the 14T or 16T jump?).
    I couldn't get a Campagnolo Racing-T triple front derailleur on a Litespeed frame with 40.5cm chain stays which ran perfectly with a Campagnolo Racing-T triple crank to both upshift with the rear derailleur in all positions and not dump the chain when I paired it with an FSA Carbon Pro compact crankset.

    The Campagnolo CT (double compact) front derailleur worked perfectly though.

  11. #11
    Gear Combo Guru Chris_W's Avatar
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    I also couldn't get acceptable results using a triple FD with a compact crank, even after trying many different adjustments. I put a double FD on and it worked flawlessly.

  12. #12
    Senior Member bon_gabs's Avatar
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    I just commented yesterday about this set-up then tried it today and it works flawlesly,,felt a bit scared to down shift the first time because of a loud click on my shifter but no worries at all,works perfectly when upshifting as well,,this tread saves me some turkey money,,

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