Riding against the wind

jimmyjams
jimmyjams Posts: 784
in The cake stop
I recently came across this graphic and I wondered how true it might be (with variations related to power output).



An acquaintance of mine, a good amateur cyclist (looks a bit like Pogacar, or rather how Pogacar might look when he reaches 40 years old) said he feels, in order to better one's hill-climbing ability, riding against the wind is just as good as riding up hills. But I'm not convinced.

I feel the figures in the graphic inaccurate – against a headwind of 15-20 km/hr, my speed doesn't drop by 30% (as the graph suggests), while feel against a headwind of 15-20 km/hr feels more than than a 2% slope (as the graph suggests).

Any comments?

Comments

  • MidlandsGrimpeur2
    MidlandsGrimpeur2 Posts: 2,129
    I agree the numbers do seem slightly exaggerated. I have no ability to test the maths though, far beyond my expertise!

    As per hills vs headwind to inprove climbing (or cycling ability in general), anything that forces you to ride at or around a threshold, either aerobic or anaerobic, is going to make you fitter, I don't really see terrain or conditions making much difference.

    For example if your ftp is 250, then 60mins at 220 watts is going to be a good tempo workout. It doesn't really matter if that is on a climb or into a 20mph headwind, 220 watts is 220 watts.
  • pblakeney
    pblakeney Posts: 27,493
    That chart looks too linear for my liking. I find headwind drag to be more geometrical progression. FWIW I treat headwinds same as climbs. As it gets harder I go slower and accept it.
    The above may be fact, or fiction, I may be serious, I may be jesting.
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  • capt_slog
    capt_slog Posts: 3,974
    edited July 2023
    pblakeney said:

    That chart looks too linear for my liking. I find headwind drag to be more geometrical progression. FWIW I treat headwinds same as climbs. As it gets harder I go slower and accept it.

    I don't know how to do the calculations and can't be @rsed to find out, but it doesn't look right.

    I DO know that drag increases with the square of the speed, so that twice the airflow means that you have 4x the drag.

    If you consider that with no headwind the rider is managing 30km/h on that table, he's already experiencing a 30km/h wind. So if he's managing to ride at 9.31 into a 50km/h wind, isn't he pushing through the air at 60km/h? His total air drag should have quadrupled, and he's still doing that at 180watts?

    As wind speed increases, the power needed to push through it follows the cube of the speed (not the best way of expressing this, but never mind). So if you double the speed, the power goes up by 8x.

    Someone with a better grasp of physics will be along to correct this I'm sure. :)






    The older I get, the better I was.

  • First.Aspect
    First.Aspect Posts: 17,389
    The number of decent Dutch climbers we've seen over the years does suggest the OPs friend has a point.

    Numbers are probably nonsense, and probably we're pulled from a website of someone trying to sell aerodynamic bar tape or someshit.
  • shirley_basso
    shirley_basso Posts: 6,195
    @rower63 wrote this article some time ago

    http://www.slidingseat.net/cycling/cycling.html

    scroll to 3/4 of the way down for the outputs.

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