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Translating Torque to Pulling Power

  1. Feb 6, 2015 #1
    I have an atv and wanted to know its towing capacity. I looked up specs and found that the maximum torque is 1.56 kg-m (11.28 ft-lb)/6,000 rpm. 2 questions: 1) What does this mean in layman's terms? 2) What is the towing capacity?
     
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  3. Feb 6, 2015 #2

    mfb

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    Without more details where exactly this torque can be gained and how it gets transmitted to the wheels there is no way to tell that. You'll also need details about the thing getting towed I guess (especially its coefficient of friction).
     
  4. Feb 6, 2015 #3

    berkeman

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    Welcome to the PF.

    Which ATV is it? Does it not have a manufacturer's specification for the rated towing capacity (GVW & GVTW & Hitch Weight)?

    http://www.gmc.com/trailering-towing/safe-trailer-towing-capacity.html [Broken] :-)
     
    Last edited by a moderator: May 7, 2017
  5. Feb 6, 2015 #4
    It is a 1986 Honda 200sx. I found specs online, but nothing about towing capacity...
     
  6. Feb 6, 2015 #5

    berkeman

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    Hmm. You might try looking at the specs of a more modern ATV of the same size & displacement. They should be listing GVW and the towing specs for some of them. I don't think the specs would have changed much for similar-size ATVs. :-)
     
  7. Feb 8, 2015 #6

    jim hardy

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    Towing capacity and pulling power are different concepts.

    Towing capacity will include handling characteristics like propensity to roll over , brakes, and the like .

    Pulling power? I think the term is "drawbar pull".
    Surely gear ratios are in the specs you found? (Everyplace i looked wanted a credit card.)
    Engine torque multiplied by gear ratio gives a slightly optimistic estimate of torque to rear wheels. It's optimistic because there's a few % lost to friction in the geartrain.
    That number divided by wheel radius will give a number for how hard the machine could pull provided it has traction and provided the front wheels stay on the ground.
    If you use torque in foot-lbs, use radius in feet..

    http://auto.howstuffworks.com/auto-parts/towing/equipment/tow-bars/drawbar-pull1.htm
    drawbar-pull-2.jpg

    note drawbar connection is low on tractor . That helps keep front wheels down when pulling, and helps keep trailer from toppling tractor over sideways on a downhill turn.

    old jim
     
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