Question for Frank

On Tuesday, November 1, 2016 at 4:15:50 PM UTC-7, John B Slocomb wrote:
On Tue, 1 Nov 2016 07:26:35 -0700 (PDT), Frank Krygowski
wrote:

On Tuesday, November 1, 2016 at 7:25:38 AM UTC-4, John B Slocomb wrote:

I have the feeling that there is a matter in definition here. Is
"aero" a term used only for those with their back perfectly flat, or
can it apply to someone that is leaning forward only 45 degrees?

I've found that simply moving my hands to the drops with my elbows
still straight increases coasting speed on one particular kill by just
about 1 kph. Is that not "aero"?

"Aero" is a vague word, of course. But IME moving from the drops to the
aero bar causes a similar increase in speed, perhaps even more.

A few years ago, there were some wind tunnel test results reported in _Bicycle
Quarterly_. Of course, they've appeared in other sources as well - but those
in BQ concentrated on fairly normal-looking bikes, not time trial machines or
the like.

One salient fact was that drag coefficent seemed unaffected by rider posture.
Any aero benefit came (almost?) entirely from reductions in frontal area.. If
true, that's good news, because it's far easier to notice one's own changes in
frontal area. It should be obvious, for example, whether one's elbows are
sticking out in the wind or not.

- Frank Krygowski


But one must shave the legs :-)

My guess is that shaving your legs alone makes a bigger increase in speed than using the drops. And using aero bars back far enough so that you can see ahead to miss glass on the road and observe traffic is highly unlikely to improve speed as much as using the drops.

I tried Frank's experiment and pedaling on the drops on a 5% hill increased the speed of the bike one mph. From 35 to 36 mph.

Question - why would that be of interest to anyone?

On Wednesday, November 2, 2016 at 8:07:03 PM UTC-7, Joy Beeson wrote:
On Tue, 1 Nov 2016 07:26:35 -0700 (PDT), Frank Krygowski
wrote:

"Aero" is a vague word, of course. But IME moving from the drops to the
aero bar causes a similar increase in speed, perhaps even more.

And sitting up straight and spreading yourself out is a good way to
brake when coasting down a hill.

--
Joy Beeson
joy beeson at comcast dot net
http://wlweather.net/PAGEJOY/

Uh, one hesitates to think what that means.....