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  1. #1
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    Slower in colder weather

    Does anyone think it is harder to maintain your usual "average speed" when it is really cold. Today we did our usual 42 miler which was 2 mins slower than last week, it was freezing today, last weeks was 1 min slower than the previous week. Is it the cold moist air that slows you down, bit like a golf ball in winter, or the fact that you are a bit more cautious in and out of the corners, which would probably add up over 42 miles, or is it just too cold to go as fast ?

  2. #2
    Senior Member martyn gall's Avatar
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    Im always slower in winter I find a speedo is a very disheartening thing at this time of the year. Its also windy in places as well which has a big impact

  3. #3
    Senior Member freester's Avatar
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    Air is denser. You've got more gear on. Cold air hitting your lungs hurts. You may be a bit more cautious. All of it really.

  4. #4
    Senior Member coolboarder's Avatar
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    All said, yesterday even though it was still freezing at the start of my ride and never got above 8C, my average speed was the same as a summer day and it felt easy but there wasn't a breath of wind and the sun was shining so moral was high. I think a lot of it is in the head but simple physics will tell you the air is more dense so there is more air resistance and if you then add in more (heavier & less aerodynamic) clothing, winter bike, heavier tyres, mudguards even its obvious you will go slower
    It's not your destination that counts, it is the glory of the ride. (apologies to Edward Monkton)

  5. #5
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    Not sure air density is the prevailing factor here, Big Fella. Perhaps a concern to the 'marginal gains' brigade, but I think you're closer to the mark with caution in corners.

  6. #6
    Senior Member Known by my posts [FBF]'s Avatar
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    Could it be that the moon was on the wane ?
    Gravity would be stronger and as such hills would be harder and more friction on your bearings.
    Carbon, without it life would not exist.

  7. #7
    Senior Member coolboarder's Avatar
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    Quote Originally Posted by Known by my posts [FBF] View Post
    Could it be that the moon was on the wane ?
    Gravity would be stronger and as such hills would be harder and more friction on your bearings.
    You may mock but the density of air at 30C which is a reasonably hot summer's day is 1.164 kg/cuM and at 0C which is not especially cold for the winter, 1.292 this is a difference of 10% and from 35C (1.145) to -5C (1.316) there is a difference of 15%. I think that is a bit more than marginal, in fact its bloody significant which is one reason why the Olympic velodrome was so warm.
    Last edited by coolboarder; 12th November 2012 at 2:16 PM.
    It's not your destination that counts, it is the glory of the ride. (apologies to Edward Monkton)

  8. #8
    Senior Member Known by my posts [FBF]'s Avatar
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    Quote Originally Posted by coolboarder View Post
    You may mock ................
    You didnt make allowances for humidity or altitude or barometric pressure,
    which, if my memory serves me correctly, climbing to 1500 feet and the temperature is 0.1 in 92% humidity when the pressure is 895 would be the same as riding in the velodrome.
    Carbon, without it life would not exist.

  9. #9
    Senior Member Known by my posts [FBF]'s Avatar
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    I've been doing some research and worked out the following
    Newton's equation of gravitational force: F = GMM/r^2 (force in newtons, gravitational constant in newton meters squared per kilo squared, mass 1 and mass 2 in kg, radius/distance between the two bodies in meters, where G = 6.674x10^-11Nm^2/kg^2)

    Equation 1, force between two people on bicycles and the road on which they are traveling:
    assuming combined human and bicycle weights of 60 and 70 kg, and a distance of 1m from the tarmac for ease.

    F = G(60)(70)/1^2
    F = 4200G = 4200(6.674x10^-11) = 2.80308x10^-7 N

    Equation 2, force between a bike wheel hub and the tarmac:
    assuming the force isnt acting on a white line (seeing as the distance between the white line and the tyre would be effectively zero, putting a zero in the denominator of the force equation and yielding an undefined result), so let's say... 0.5m distance, 60kg rider, 6kg wheel.

    F = G(60)(6)/(0.5^2)
    F = 1440G = 1440(6.674x10^-11) = 9.61056x10^-8 N

    Equation 3, force between human at arbitrary point on the earth's surface and the moon:
    assuming 60kg person again, distance to jupiter at ~588,000,000,000 m at it's closest approach (the closest approach being when all the mangoats would assume jupiter and the other planets to have their most potent effect on wide scale celestial mind control tricks), mass of jupiter is 1.898610^27 kg.

    F = G(60)(1.8986x10^27)/((588,000,000,000)^2)
    F = 3.29481x10^5(G) = 3.29481x10^5(6.674x10^-11)
    F = 2.1989x10^-5 N

    for ease, we'll show the results one after another expressed to the same power:

    F1 (people on bikes) = 280.308x10^-9 N
    F2 (bike and wheel) = 96.1056x10^-9 N
    F3 (jupiter and person on bike) = 21989x10^-9N

    21989/280.308 = a 78.45 times greater force from Jupiter on one person than two people on bikes
    21989/96.1056 = a 228.8 times greater force from Jupiter on a person than the bike and wheel on each other

    therefore, the "basic mathematics" prove that you are wrong and a the force of the moon would [on a cold day] have an effect
    Carbon, without it life would not exist.

  10. #10
    Senior Member coolboarder's Avatar
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    Quote Originally Posted by Known by my posts [FBF] View Post
    You didn't make allowances for humidity or altitude or barometric pressure,
    True and this is why records are set at altitude but the OP didn't beg that question so I didn't answer it. I could quote you figures on all this if you really want but I think this thread is already getting silly. As for your next post you clearly have too much time on your hands and/or need to get a life.
    It's not your destination that counts, it is the glory of the ride. (apologies to Edward Monkton)

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