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  1. #1
    powered by Racer Ex gsteinb's Avatar
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    A better argument for today - how much weight matters

    One bike weights 1/4 pound more than the other. How much of a difference does it make over an hour going up hill?

  2. #2
    Senior Member Homebrew01's Avatar
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    How steep is the hill ?

    http://kreuzotter.de/english/espeed.htm

    At 300 watts, save 1 minute over 10 miles at 10% (according to them.... sounds like too much)

    Calculator seems to not work correctly. I change variables, but the result sometimes stays the same.
    Last edited by Homebrew01; 06-18-14 at 10:27 AM.
    Bikes: Old steel race bikes, old Cannondale race bikes, less old Cannondale race bike, crappy old mtn bike

  3. #3
    powered by Racer Ex gsteinb's Avatar
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    8.5%

  4. #4
    Making a kilometer blurry waterrockets's Avatar
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    What's the total elevation gain on the hill in question?

    You're looking at 0.1134kg.
    Force required to lift it F=ma, so F = 0.1134kg * 9.8m/s^2 = 1.111N
    Work = F * d = 1.111N * elevation gain in meters. For a 3000ft climb, it's 914m, so 1.111N * 914m = 1016Nm = 1016J of work
    If you spend an hour climbing this hill, you've 1016J / 60*60s = 0.28J/s = 0.28W​ to get this 1/4 lb. up the hill at that pace.

    So just substitute your elevation in meters and the Strava KOM time for duration and recalculate.

  5. #5
    **** that mattm's Avatar
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    Quote Originally Posted by gsteinb View Post
    One bike weights 1/4 pound more than the other. How much of a difference does it make over an hour going up hill?
    41 seconds?
    pro-meter: lol

    blog

  6. #6
    Senior Member Homebrew01's Avatar
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    33 seconds of you're racing
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  7. #7
    starting pistol means war YMCA's Avatar
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    Quote Originally Posted by gsteinb View Post
    One bike weights 1/4 pound more than the other. How much of a difference does it make over an hour going up hill?
    too much thinking involved
    ride up on the favorite bike and let the chips fall

  8. #8
    powered by Racer Ex gsteinb's Avatar
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    I'm not thinking. Just looking to start a weight weenies argument.

    the bikes are same, but for 1/4 pound difference in the groups.

  9. #9
    Making a kilometer blurry waterrockets's Avatar
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    Quote Originally Posted by gsteinb View Post
    Just looking to start a weight weenies argument.
    My method of calculation is best. Argument settled. You gonna lock it now?

  10. #10
    starting pistol means war YMCA's Avatar
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    winners win on anything; how's that?

  11. #11
    In the Pain Cave thechemist's Avatar
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    well my question would be what would the advantage of using the heavier bike be If you can go lighter I say go lighter. My thought process has always been go as light as possible until it starts becoming less aero or less stable to handle. That or the $$ just is not worth the marginal gain .


    I do know that if I was 10 pounds lighter in one of my April road races that I wouldn't have been dropped.

  12. #12
    Senior Member Homebrew01's Avatar
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    Quote Originally Posted by gsteinb View Post
    I'm not thinking. Just looking to start a weight weenies argument.
    the bikes are same, but for 1/4 pound difference in the groups.
    Reported
    Bikes: Old steel race bikes, old Cannondale race bikes, less old Cannondale race bike, crappy old mtn bike

  13. #13
    powered by Racer Ex gsteinb's Avatar
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    Quote Originally Posted by Homebrew01 View Post
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    **** you, you ****ing ****

  14. #14
    powered by Racer Ex gsteinb's Avatar
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    Quote Originally Posted by waterrockets View Post
    What's the total elevation gain on the hill in question?
    3500 feet give or take 100

  15. #15
    Making a kilometer blurry waterrockets's Avatar
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    Quote Originally Posted by gsteinb View Post
    3500 feet give or take 100
    expected elapsed time?

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    Ninny globecanvas's Avatar
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    Strava Segment | Whiteface Hillclimb

    According to Bike Calculator 0.25 lbs is worth 3.6 minutes [edit: seconds], making some other reasonable assumptions.
    Last edited by globecanvas; 08-22-14 at 12:46 PM.

  17. #17
    powered by Racer Ex gsteinb's Avatar
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    Quote Originally Posted by waterrockets View Post
    expected elapsed time?
    something south of 52 the good lord willing.

  18. #18
    powered by Racer Ex gsteinb's Avatar
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    Quote Originally Posted by globecanvas View Post
    Strava Segment | Whiteface Hillclimb

    According to Bike Calculator 0.25 lbs is worth 3.6 minutes, making some other reasonable assumptions.

    gees that can't be true can it? jinkies, just losing all the extra clothes I normally haul to the top, along with the repair stuff, and using race wheels dear god I'm losing pounds. I'm going to rip a hole in the god damn space time continuum.

  19. #19
    Senior Member
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    How much does a McDonalds quarter-pounder weigh?

  20. #20
    powered by Racer Ex gsteinb's Avatar
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  21. #21
    Ninny globecanvas's Avatar
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    Sorry... heh... 3.6 seconds

    155 lb rider/clothes/shoes + 17 lb bike @ 300w => 51:06. 17.25 lb bike => 51:10.

  22. #22
    powered by Racer Ex gsteinb's Avatar
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    well that's ****ing deflating

  23. #23
    Making a kilometer blurry waterrockets's Avatar
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    Yeah, I'm seeing a difference of 0.38W to maintain speed with the extra 1/4 lb, assuming you'll be in a break with somebody, and in the pack before that, your time will actually be the same. Throughout most of the race, you'll be costing yourself a whole 1/3 of a Watt.

    I say I still win, because power needed to keep up is the important figure, unless this is a time trial.

    It's still ****ing deflating though.

  24. #24
    powered by Racer Ex gsteinb's Avatar
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    mass start hill climb. it shatters though and everyone rides alone.

    for 3 seconds I'll just ride the bike I keep up there so I don't have to bring extra stuff back and forth

  25. #25
    Senior Member hack's Avatar
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    But wait...what if that 1/4 pound is in the wheels because, you know ... rotational weight. 3.6 seconds could become 3.611 seconds.
    Cat 2 upgrade status: never

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