Drafting - wind resistance

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science_fox
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Drafting - wind resistance

Post by science_fox » Wed Nov 13, 2019 12:16 pm

Most obvious whilst cycling, but presumably relevant elsewhere:

If there's a headwind, and I tuck in behind a fellow rider, I get a significant energy reduction as I don't need to push against the wind so hard. So far so obvious.

If there's the miracle of a tailwind, what effect does drafting have?
Does having a drafter reduce the benefit the front rider would normally feel?
Is there as much benefit for the draftee?

I think that providing you're cycling faster than the windspeed (reasonable in most conditions?) there should be no difference to a headwind, just slightly less benefit. But I'm not sure.

tom p
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Re: Drafting - wind resistance

Post by tom p » Wed Nov 13, 2019 12:26 pm

science_fox wrote:
Wed Nov 13, 2019 12:16 pm
Most obvious whilst cycling, but presumably relevant elsewhere:

If there's a headwind, and I tuck in behind a fellow rider, I get a significant energy reduction as I don't need to push against the wind so hard. So far so obvious.

If there's the miracle of a tailwind, what effect does drafting have?
Does having a drafter reduce the benefit the front rider would normally feel?
Is there as much benefit for the draftee?

I think that providing you're cycling faster than the windspeed (reasonable in most conditions?) there should be no difference to a headwind, just slightly less benefit. But I'm not sure.
Hmmm, good question. I've often wondered about tailwinds & how aerodynamic to be.
I have aero bars on my bike and am very happy in a tuck position, so in a headwind or side wind, or even when it's calm, I'm usually tucked-up.
From January I'll be doing 50 km to work with a couple of mates, riding north-east through Hollands. Should be plenty of tailwinds in the morning & headwinds in the evening, so we'll try and experiment to find out. one of my mates has got a v. expensive bike, and I shouldn't wonder if he's got power meters, so we should be able to see.

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Re: Drafting - wind resistance

Post by dyqik » Wed Nov 13, 2019 12:29 pm

If it's a headwind in the frame of reference of the riders, then the lead rider takes the brunt of it.

If it's a tailwind in the frame of reference of the riders, the trail rider gets the benefit, and the lead rider gets less of one than they otherwise would.

It's also possible to position your body with sidewinds to sail a bit, and get some small benefit.

greyspoke
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Re: Drafting - wind resistance

Post by greyspoke » Wed Nov 13, 2019 3:18 pm

If there is a virtual tailwind when up to speed, you should be riding abreast, if a headwind, in a line.

Possibly if you all pedalled in sync you might try an echelon like geese.

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Re: Drafting - wind resistance

Post by Woodchopper » Wed Nov 13, 2019 9:10 pm

[Moved the topic to Nerd Lab as it seems to fit better here]

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