Quoting Peter Cole <[email hidden]>:
Quoted message said:Sandy said:"Peter Cole" <[email hidden]> a =E9crit dans le message de :
Quoted message said:Again, I don't see the point of mentioning 10 mph aerodynamics. That's
an oxymoron.
Would you also be saying that a 10 or 15 or 20 mph straight tailwind is of
no consequence ? Sounds like that to me.
I'm afraid I have no idea what you're talking about.
With a powerful tailwind, you may have very high power losses to rolling
resistance (since you are going very quickly) and a low power loss to the
apparent headwind.
For example, imagine that I normally cruise at 20mph, and 4/5 of my power
goes to air resistance. Then I ride in a 20mph tailwind - very very
strong, given the ground effects - at 30mph, which we will imagine is as
fast as I want to go. Then rolling resistance consumes 30% of my normal
power output (linearly with speed), and wind 30% (remember that power to
air resistance is airspeed * airspeed * groundspeed, so we have 80%
divided by 4 for halved airspeed but then multiplied for 3/2 for increased
groundspeed).
Even if I increase power output to my normal 100%, about 35% will go to
RR. Hence rolling resistance changes are more effective in a tailwind. Er,
so I have no idea what his point is either.
--
David Damerell <[email hidden]> Distortion Field!
Today is First Oneiros, April.