Chainring question: 53/42 or 50/39

Discussion in 'Road Bikes' started by aeonderdonk, Mar 2, 2010.

  1. aeonderdonk

    aeonderdonk New Member

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    I am looking at a used bike that has two options for a double chainring 53/42 or 50/39.

    I live in the piedmont of North Carolina which has some rolling hills and flat stretches, nothing tooooo steep like further west in the mountains.

    Which would you recommend if the bulk of my riding is around my home with maybe a few trips to steeper terrain?
     
  2. stdu007

    stdu007 New Member

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    i will go for the 50/39 (most commun is 50/34)
     

  3. aeonderdonk

    aeonderdonk New Member

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    Since I'm new to roadbiking does this make sense?

    53/42 would be a faster ride but tougher on hills? How much faster/tougher would it make it?
     
  4. Xela

    Xela New Member Tavern Member

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    I ride a 50/34. I feel the lower gears for climbing around here far outweigh the speed trade-off.

    Here's some numbers.

    Assumptions: 11 tooth rear cassette cog. 100 rpm. 700 C wheel.

    The math predicts a top speed of 35.2 for the 50 tooth chainring vs 37.3 mph for the 53 tooth.
     
  5. aeonderdonk

    aeonderdonk New Member

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    I doubt I'll be going that fast, particularly not that often. Good call.
     
  6. Xela

    Xela New Member Tavern Member

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    Yeah, me either. On my 50, I find I can get up to about 39 mph with a cadence of 110 rpms. Usually, I only exceed this speed when I'm coasting down a hill, so it's no big deal that I'm out of gears.
     
  7. Skidmark

    Skidmark Cycling for life

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    I am thrilled to read that Xela. The bike I have in lay-away is what they call a compact which is the 50 ring in lieu of the 53. Not a lot of hills here but my legs are old. :)
     
  8. Xela

    Xela New Member Tavern Member

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    I personally think you made the right choice. I love my compacts. I went directly from a bike with a 53 tooth to the compacts. No doubt in my mind it was the right call for me.
     
  9. Skidmark

    Skidmark Cycling for life

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    I got the chance to ride a Tarmac Comp Rival today with the 53 / 39. I must say it was a fantastic bike. First I was suprised at how much better the all carbon bike rode where even a novice like me could feel it. Of course its pretty flat here, but I could crank the 53 okay but I can see where in a racing situation I would be left in the preverbal dust as my cranky knees will not let me push to hard early. But thats not my gig anyway. I am deciding tonight on switching to that bike, I really liked it!
     
  10. chh55

    chh55 Drink plenty of water!!!

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    Lots of folks have opted for a compact system in the past few years and I don't see the trend abating. Maybe soon it will be the standard. I like my 53 39 setup, with a 12-27 cassette I get a low enough gear for just about anything. If I rent a bike on Mallorca I think I'll try a compact though.
     
  11. jad3

    jad3 Helmet up, wheels down.

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    Agreed - The 39 is the key...check the gear inches and it becomes apparent ...
    Gives you a lot more "Easy" for a small reduction in "Hard". Then again...all are pretty close so it isn't too much to stress about.

    Description...
    http://www.inlandempirecycling.com/Cycling/calculate_gear_inch_chart.htm


    Front Rear Wheel Gear Inch Ratio
    39 25 700 42.12 1.56
    42 25 700 45.36 1.68
    39 23 700 45.78 1.70
    42 23 700 49.30 1.83
    39 21 700 50.14 1.86
    42 21 700 54.00 2.00
    50 25 700 54.00 2.00
    39 19 700 55.42 2.05
    53 25 700 57.24 2.12
    50 23 700 58.70 2.17
    42 19 700 59.68 2.21
    39 17 700 61.94 2.29
    53 23 700 62.22 2.30
    50 21 700 64.29 2.38
    42 17 700 66.71 2.47
    53 21 700 68.14 2.52
    39 15 700 70.20 2.60
    50 19 700 71.05 2.63
    39 14 700 75.21 2.79
    53 19 700 75.32 2.79
    42 15 700 75.60 2.80
    50 17 700 79.41 2.94
    39 13 700 81.00 3.00
    42 14 700 81.00 3.00
    53 17 700 84.18 3.12
    42 13 700 87.23 3.23
    39 12 700 87.75 3.25
    50 15 700 90.00 3.33
    42 12 700 94.50 3.50
    53 15 700 95.40 3.53
    50 14 700 96.43 3.57
    53 14 700 102.21 3.79
    50 13 700 103.85 3.85
    53 13 700 110.08 4.08
    50 12 700 112.50 4.17
    53 12 700 119.25 4.42
     
    Last edited: Mar 7, 2010