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  1. #1
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    1x11 gear math correct?

    Currently have a 3x9 setup on a MK1 Nomad and looking to jump to 1x11 on X1

    I have a 22-32-44 front and 11-34 rear at present.

    By my math comparing...
    The top end
    Going to a 34 with the 10-42 I'd lose 1 gear off the back compared to the 44.

    The bottom end I'd lose about 2 1/2 gears off the back when in the granny.

    Is this about right and in relation to where the current front 3 rings are where does single ring end up? about where the middle ring is and does the drive side crank end up closer to the frame?

  2. #2
    dadamamabooboo
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    Quote Originally Posted by Calzor Suzay View Post
    Currently have a 3x9 setup on a MK1 Nomad and looking to jump to 1x11 on X1

    I have a 22-32-44 front and 11-34 rear at present.

    By my math comparing...
    The top end
    Going to a 34 with the 10-42 I'd lose 1 gear off the back compared to the 44.

    The bottom end I'd lose about 2 1/2 gears off the back when in the granny.

    Is this about right and in relation to where the current front 3 rings are where does single ring end up? about where the middle ring is and does the drive side crank end up closer to the frame?
    assuming you have a29er size tire you're going from a range of 19 gear-inches in granny low, 116 up high on the 44..to a range of 23 on the 42 cog to 98 on the 10 cog....depends on how many gear-inches you consider 'a gear', but for me I'd see those gear-inch shavings as losing one off the top and roughly 2 off the bottom.
    2011 Trek Mamba 29er 21", SRAM 9-sp X5, X5 RD, SRAM X7 22/32/44 & Shimano Deore FD, HG-61 custom 9-sp 11-36, M475 rear hub

  3. #3
    NedwannaB
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    Quote Originally Posted by Calzor Suzay View Post
    Currently have a 3x9 setup on a MK1 Nomad and looking to jump to 1x11 on X1

    I have a 22-32-44 front and 11-34 rear at present.

    By my math comparing...
    The top end
    Going to a 34 with the 10-42 I'd lose 1 gear off the back compared to the 44.

    The bottom end I'd lose about 2 1/2 gears off the back when in the granny.

    Is this about right and in relation to where the current front 3 rings are where does single ring end up? about where the middle ring is and does the drive side crank end up closer to the frame?
    Seeing that you're on a All Mtn 26r I doubt you'll miss the little bit of top end you'd lose. Question would really be how often are you doing your climbing in your 32t/34
    cog? If you're in that config for your "granny" with no prob then I'd say that with the 34/36t on the X drivetrain would be pretty close, giving you a bailout with the 42t.
    Really depends on your fitness, riding style and trail terrain.

    As for 1x ring if planing to use on your 3x crank set yes it will end up in the middle spot. No the bb spacers should not change. Issue may be if the 34t would encroach on linkage don't think I've seen probs with one on that bike.
    Last edited by JMac47; 5 Days Ago at 10:26 AM. Reason: Typo more info
    Wait,who did he tell you that?....

  4. #4
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    Just to clarify wheel size it's a 26" all mountain bike

    I tend to only use the 44/11 combo when I'm on tarmac heading to/from riding location, don't think I ever pick it when riding the trails.

    As for the other end I barely ever use the granny ring, I tend to 'muscle up' as I'm more of a pedal grinder than spinner so can be in the middle 32 and rear 34 for nearly all steeper climbs round here and sometimes could do with a little extra. I tend not to though as the drop from 32/24 to 22/24 ends up making me spin, lift the wheel, lose traction and tend to bail out anyway.

    My thinking with the 1x11 I can get to what was my 32/24 and still have a bail out gear that isn't such a crazy drop and the weight saving and ease of complexity dumping the front gears.

  5. #5
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    You'll lose some in overall gear ratio, but if you can lose less than two gears on the bottom you'll be absolutely thrilled. Having a 32::42 is a good enough bail out gear for most occasions, unless you need to climb some seriously steep stuff (for my uses anything more vertical than I can pedal up in that ratio, it's more energy efficient to just walk).

    Losing gears off the top is almost helpful, unless you spend time going insanely fast on the mountain bike, the big chainrings are the needless deadweight you gain, and a 32::10 is actually a gear ratio that gets you to speeds where you're more concerned about aerodynamics than spinning yourself out, so you seriously won't miss those gears.

  6. #6
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    Look at the hard numbers.
    Gain ratio, Gear inches, even mph @ cadence. compare until your heart's content.

    Sheldon Brown's Bicycle Gear Calculator

    I have no connection to Sheldon Brown, but his legacy and website are a staggering source of bike knowledge. Highly recommended.

  7. #7
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    I found a better one here, allows comparison and 11 speed drive train http://www.gear-calculator.com/

  8. #8
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    Best gear calculator I've found:

    BikeCalc.com - Fixed Gear Calculator

  9. #9
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    BikeCalc.com - Bicycle Gear Inches Chart

    That one^ is my fav also, much easier to use than Sheldon's IMO.

  10. #10
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    I'm making a similar gearing change with my new bike build. Except I'm making it a 1x10, but with a 42t granny. I chose a 28t chainring to give me more low end gearing. I don't care about losing top end gears.

  11. #11
    Maromero
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    Another gear calculator, I like that it allows you to compare multiple gearing in the same page Bike Gears calculator

  12. #12
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    You are not changing wheel sizes so just divide chain ring by cog.

    Your shortest gear is 22/34 = 0.64
    Your tallest gear is 44/11 = 4

    Switching to 1x you loose indeed at least 4 gears (maybe 5 depending on what chain ring you end up with), both at the low and high end.

    Shortest 34/42 = 0.80
    Tallest 34/10 = 3.4

    If you had an 1136 or 1140 cassette your triple would have an even bigger advantage. If I were you I would go dual 28-38 by 1140 or 1142: way cheaper and better range ... or keep my triple. (I am on 30 x 1142, it works but I give up the high gears and loose one low gear.)
    Last edited by Davide; 2 Days Ago at 08:30 AM.

  13. #13
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    Deleted.

    I'm grumpy and will keep my smartass comments to myself.

  14. #14
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    Quote Originally Posted by Bikerector View Post
    Best gear calculator I've found:

    BikeCalc.com - Fixed Gear Calculator
    I love this gear calculator. Its very visual.

    It blows me away that I have actually widened the toothcount on my 2x10 front rings, and I still effectively only have 13 speeds.


    (11-36 rear, 22-34 front)

  15. #15
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    Quote Originally Posted by Calzor Suzay View Post
    Currently have a 3x9 setup on a MK1 Nomad and looking to jump to 1x11 on X1

    I have a 22-32-44 front and 11-34 rear at present.

    By my math comparing...
    The top end
    Going to a 34 with the 10-42 I'd lose 1 gear off the back compared to the 44.

    The bottom end I'd lose about 2 1/2 gears off the back when in the granny.

    Is this about right and in relation to where the current front 3 rings are where does single ring end up? about where the middle ring is and does the drive side crank end up closer to the frame?
    Factoring in your change in wheel size, you will lose gear on the top and 2 gears on the bottom. You lose only 2 gears total.

  16. #16
    NedwannaB
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    Quote Originally Posted by craigsj View Post
    Factoring in your change in wheel size, you will lose gear on the top and 2 gears on the bottom. You lose only 2 gears total.
    Change in wheel size?
    Wait,who did he tell you that?....

  17. #17
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    Quote Originally Posted by JMac47 View Post
    Change in wheel size?
    Sorry, I got confused in the thread. I thought it became a 29er.

    If the wheel size doesn't change, then the loss is 1 gear on the top and 1 3/4 gears on the bottom. The total is only 2 3/4 gears in any case.

    log[(44/22 * 34/11) / (42/10)] / log[1.15] = 2.8 gears total loss

    log[(44/11) / (34/10)] / log[1.15] = 1.2 gears on top
    log[(22/34) / (34/42)] / log[1.15] = -1.6 gears on bottom

    log[1.10] / log[1.15] = 0.7 gears up for 29er vs 26er (irrelevant here)

    It's only a matter of how the gears are distributed. It is not 5 gears

  18. #18
    NedwannaB
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    Quote Originally Posted by craigsj View Post
    Sorry, I got confused in the thread. I thought it became a 29er.

    If the wheel size doesn't change, then the loss is 1 gear on the top and 1 3/4 gears on the bottom. The total is only 2 3/4 gears in any case.

    log[(44/22 * 34/11) / (42/10)] / log[1.15] = 2.8 gears total loss

    log[(44/11) / (34/10)] / log[1.15] = 1.2 gears on top
    log[(22/34) / (34/42)] / log[1.15] = -1.6 gears on bottom

    log[1.10] / log[1.15] = 0.7 gears up for 29er vs 26er (irrelevant here)

    It's only a matter of how the gears are distributed. It is not 5 gears
    Was going to say it is about "changing gears" anyways.
    Wait,who did he tell you that?....

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