Re: Today's Ride

On Sat, 21 Jun 2025 20:12:02 -0400, Frank Krygowski
<frkrygow@sbcglobal.net> wrote:

On 6/21/2025 4:59 PM, cyclintom wrote:

We had a 25 mph headwind all the way out with 35 mph gusts.I wouold be riding along working pretty hard at 12.5 mph and as the gusts hit I would be instantly at 11 mph. Normally this would be somewhat compensated for by a tailwind on the way back but I guess it was more a cross wind as we turned back.

>
Congratulations! 12.5 mph into a 25 mph headwind takes quite a bit of
power, something close to 400 Watts. I'm very amazed a guy your age can
do that!
>

23 miles and average speed of only 8.18 miles per hour average ...

>
Ah. 8.18 mph sounds much more believable. That might be around 200 Watts.

This is easier and includes more parameters.
I had to guesstimate on some of the values because Tom doesn't
disclose which bicycle he's riding, how much he weight, roadway slope,
etc.

<https://www.gribble.org/cycling/power_v_speed.html?units=imperial&rp_wr=199.999&rp_wb=17&rp_a=5.9998&rp_cd=0.63&rp_dtl=2&ep_crr=0.01&ep_rho=0.078035&ep_g=0&ep_headwind=25&p2v=200&v2p=22>
To maintain a ground speed of 12.29 mph into a 25 mph headwind, Tom's
pedaling needs to produce 396.28 watts of power.
(Punch the Units: Metric button to change everything to metric).

At 8.18 mph, 217 watts of power is required.  Yeah, that's more
realistic.
<https://www.gribble.org/cycling/power_v_speed.html?units=imperial&rp_wr=199.999&rp_wb=17&rp_a=5.9998&rp_cd=0.63&rp_dtl=2&ep_crr=0.01&ep_rho=0.078035&ep_g=0&ep_headwind=25&p2v=200&v2p=22>

Without a headwind, 8.18 mph requires on 47 watts of power.


--
Jeff Liebermann                 jeffl@cruzio.com
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