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  1. #1
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    I just ordered a crank (gearing question)

    I just ordered a FSA Afterburner 386 megaexo (2x9) crank. I'd prefer a double over a triple almost any day, mostly because of the quick high to low, low to high change in gearing. I am a little worried that the gearing will be too high. Anyone have any thoughts?

    My original (low) gearing was:
    22front - 34rear =
    -----80rpm 4.42mph
    -----90rpm 4.97mph
    ----100rpm 5.5mph

    New gearing (low):
    27front - 34rear =
    -----80rpm 5.4mph
    -----90rpm 6.1mph
    ----100rpm 6.78mph


    I was going to post an image but I only have 7 posts ;(

  2. #2
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    You'll be fine. No doubt it will be a little more difficult as you're eliminating your easiest and most difficult gears when going from 3x to 2x, but you'll just have to get a little more leg muscle. I have the K-force 386 carbon crank running 40/27 and where I ride I use the 40 solely, then when into higher elevation I use the 27. I can only think of a time or two where it would be nice to have something lower, that being said I've never had to walk because of it being too difficult, at least around North Carolina anyway.

  3. #3
    Nouveau Retrogrouch SuperModerator
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    Quote Originally Posted by sixteenornumber View Post
    I just ordered a FSA Afterburner 386 megaexo (2x9) crank. I'd prefer a double over a triple almost any day, mostly because of the quick high to low, low to high change in gearing. I am a little worried that the gearing will be too high. Anyone have any thoughts?

    My original (low) gearing was:
    22front - 34rear =
    -----80rpm 4.42mph
    -----90rpm 4.97mph
    ----100rpm 5.5mph

    New gearing (low):
    27front - 34rear =
    -----80rpm 5.4mph
    -----90rpm 6.1mph
    ----100rpm 6.78mph


    I was going to post an image but I only have 7 posts ;(
    If you commonly use the 22x34 and 22x30, then yes, you made a mistake. 27x34 is higher than your two lowest ratios with the 22T ring.
    mtbtires.com
    The trouble with common sense is it is no longer common

  4. #4
    ballbuster
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    Depends...

    Quote Originally Posted by sixteenornumber View Post
    I just ordered a FSA Afterburner 386 megaexo (2x9) crank. I'd prefer a double over a triple almost any day, mostly because of the quick high to low, low to high change in gearing. I am a little worried that the gearing will be too high. Anyone have any thoughts?

    My original (low) gearing was:
    22front - 34rear =
    -----80rpm 4.42mph
    -----90rpm 4.97mph
    ----100rpm 5.5mph

    New gearing (low):
    27front - 34rear =
    -----80rpm 5.4mph
    -----90rpm 6.1mph
    ----100rpm 6.78mph


    I was going to post an image but I only have 7 posts ;(
    ... on your level of fitness and where you ride, obviously.

    I've been riding for a while now, but I'm still a heavy-ish guy who can't ride enough to get in good enough shape to push taller gears. Also, there are a lot of steep long hills around here.

    I couldn't push a 27*34 up many of them. I run a 20*36 on my heavier suspension 29er bike, and I'm glad I have it.

    I also dont' like the big gap between chainrings, so I run 20/30/42 up front. I can click up the two or three cogs in back and in one fluid motion I shift both front and rear derailleurs into middle ring and big cog and only miss one crank rotation.

    So, up to your level of fitness and the trails you ride.

  5. #5
    mtbr member
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    Quote Originally Posted by sixteenornumber View Post
    Anyone have any thoughts?
    Ask questions before you buy stuff.

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