Uphill versus Against the Wind

General cycling advice ( NOT technical ! )
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geomannie
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Re: Uphill versus Against the Wind

Post by geomannie »

Just back from battling for 20 miles into a 20mph headwind. Give me a hill any day!
geomannie
MikeF
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Re: Uphill versus Against the Wind

Post by MikeF »

Jdsk wrote: 27 Jan 2022, 3:16pm The dependence of power on speed is very different: for climbing it's proportional to speed but for air resistance it's proportional to the cube of (air) speed.

Jonathan
Why is it proportional to the cube when air resistance is proportional to the square of the vehicle speed. Something perhaps drivers of electric cars might become aware of if they want the greatest range between charges. :wink:
"It takes a genius to spot the obvious" - my old physics master.
I don't peddle bikes.
simonhill
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Re: Uphill versus Against the Wind

Post by simonhill »

I have now read the link posted earlier viewtopic.php?t=101012

It's pretty much clever people with maths and its complicated, but lots of interesting stuff.

I often call Southend seafront the longest hill in Essex when pedalling against a strong wind. I can't do the maths, so I'll improvise. Today was gentle Sou Westerly so about 2% hill equivalent. Tomorrow, plus 20 mph wind, so I'll call that a 5-6%. I'm sure this isn't (too) accurate, but if I don't tell anyone then it'll be alright.

By the way, people who think the headwind shifts when they turn round should check out "apparent wind".
Jdsk
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Re: Uphill versus Against the Wind

Post by Jdsk »

MikeF wrote: 28 Jan 2022, 5:07pm
Jdsk wrote: 27 Jan 2022, 3:16pm The dependence of power on speed is very different: for climbing it's proportional to speed but for air resistance it's proportional to the cube of (air) speed.
Why is it proportional to the cube when air resistance is proportional to the square of the vehicle speed.
The aerodynamic force is proportional to the square of the air speed. For any force the power required is the product of the force and the speed (in the relevant direction). So the power is proportional to the cube.

Jonathan
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mjr
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Re: Uphill versus Against the Wind

Post by mjr »

thirdcrank wrote: 28 Jan 2022, 3:58pm IMO a big difference (in spite of my belief that the highwaymen jack up all hills every winter to increase their gradients)
I have recently started campaigning for Norfolk Highways to be led by an adherent of MC Escher, so that all roads will be made downhill in both directions!
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Psamathe
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Re: Uphill versus Against the Wind

Post by Psamathe »

mjr wrote: 28 Jan 2022, 5:33pm
thirdcrank wrote: 28 Jan 2022, 3:58pm IMO a big difference (in spite of my belief that the highwaymen jack up all hills every winter to increase their gradients)
I have recently started campaigning for Norfolk Highways to be led by an adherent of MC Escher, so that all roads will be made downhill in both directions!
By the time they've "surface dressed" them after leaving all the potholes unfixed they'd still be unridable.

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ANTONISH
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Re: Uphill versus Against the Wind

Post by ANTONISH »

thirdcrank wrote: 28 Jan 2022, 3:58pm We must have had other threads on this besides that linked above.

IMO a big difference (in spite of my belief that the highwaymen jack up all hills every winter to increase their gradients) is that hills are dependable where the wind isn't. Riding up a hill is money in the bank, or at least pedalling effort converted to potential energy. Wind speed and direction are largely a matter of luck, and as has been pointed out, struggling into the wind carries no guarantee of anything helpful on the return journey. Descending hills doesn't mean getting all the investment back as the energy may be lost through braking and then greater speed = more wind resistance, especially if it's blowing a gale into your face but overall, imo climbing = achievement while riding into a headwind = annoyance at least.
I have to agree with this - a long climb like the tourmalet or Galibier offers and end which eventually comes into sight.
The most miserable couple of days I have spent was cycling from Utrecht to the Hook into an interminable headwind.
borisface
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Re: Uphill versus Against the Wind

Post by borisface »

Go to Crete where you can combine uphill and against the wind!
PJ520
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Re: Uphill versus Against the Wind

Post by PJ520 »

nirakaro wrote: 27 Jan 2022, 6:20pm
simonhill wrote: 27 Jan 2022, 5:42pm you often hear people talking about how much vertical they have done, but rarely about a long flat against the wind ride.
Getting up a challenging hill gives you ego-boosting bragging rights; riding against the wind is much harder to quantify, and talking about it just sounds like whingeing.
Very true. I once attempted to ride Route 66 from Chicago. Flat as a pancake with day after day of 25 - 35 mph headwinds with more forecast just wore me out. I got to New Mexico and couldn't take any more. In the end I paid somebody to drive me 150 miles to Albuquerque and flew home. I still feel like I failed. All very depressing. I did once ride from Utrecht to the Hook. This was ten times worse.
You only live once, which is enough if you do it right. - Mae West
nez
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Re: Uphill versus Against the Wind

Post by nez »

PJ520 wrote: 3 Feb 2022, 4:46pm
nirakaro wrote: 27 Jan 2022, 6:20pm
simonhill wrote: 27 Jan 2022, 5:42pm you often hear people talking about how much vertical they have done, but rarely about a long flat against the wind ride.
Getting up a challenging hill gives you ego-boosting bragging rights; riding against the wind is much harder to quantify, and talking about it just sounds like whingeing.
Very true. I once attempted to ride Route 66 from Chicago. Flat as a pancake with day after day of 25 - 35 mph headwinds with more forecast just wore me out. I got to New Mexico and couldn't take any more. In the end I paid somebody to drive me 150 miles to Albuquerque and flew home. I still feel like I failed. All very depressing.
And if you’d gone the other way? Experience in cycling and sailing says it doesn't help.
PJ520
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Re: Uphill versus Against the Wind

Post by PJ520 »

nez wrote: 3 Feb 2022, 4:51pm
PJ520 wrote: 3 Feb 2022, 4:46pm
nirakaro wrote: 27 Jan 2022, 6:20pm
Getting up a challenging hill gives you ego-boosting bragging rights; riding against the wind is much harder to quantify, and talking about it just sounds like whingeing.
Very true. I once attempted to ride Route 66 from Chicago. Flat as a pancake with day after day of 25 - 35 mph headwinds with more forecast just wore me out. I got to New Mexico and couldn't take any more. In the end I paid somebody to drive me 150 miles to Albuquerque and flew home. I still feel like I failed. All very depressing.
And if you’d gone the other way? Experience in cycling and sailing says it doesn't help.
The people I met going the other way were having the time of their lives. Just to add to the misery.
You only live once, which is enough if you do it right. - Mae West
nez
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Re: Uphill versus Against the Wind

Post by nez »

Squish squash for another pet theory
CliveyT
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Re: Uphill versus Against the Wind

Post by CliveyT »

One other problem with headwinds in winter is that they are cold. At least hills warm you up in one direction
David2504
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Re: Uphill versus Against the Wind

Post by David2504 »

Well this week has certainly been putting the headwind theory to the test. And I can testify it’s bloody awful.
thirdcrank
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Re: Uphill versus Against the Wind

Post by thirdcrank »

Kinder Downfall: Strong winds force waterfall to 'flow backwards'

https://www.bbc.co.uk/news/av/uk-englan ... e-60246800
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