Tom A. wrote:

mlinenb wrote:

Any real world data with rider aboard pedaling?

Don't wind tunnels exist in the "real world"? :-/

No. The two are mutually exclusive.

The best you can do for bike+rider+pedalling is an "Aerolab" test [ie, the Eiffel equation]. Take a powermeter, the most perfectly flat stretch of road wind absolutely zero wind, and ride at the same power back and forth all day. Preferably during the heat of the day, so that temperature (and thus air density) remain constant.

Even under the most perfect conditions, there is still a significant margin for error: riding on the "rut" from cars will have different rolling resistance than riding outside of it. Cars passing you will give you an extra .2 mph on the same wattage, etc etc etc.

This is why wind tunnel tests are the best we can do - things like riders pedaling add a LOT of time [and remember time = money, on the tune of $1,000 / hr in windtunnels] to these tests. It would be nice to test every frame and wheel combination for every rider position at every yaw angle, but remember that there are 10ish top-of-the-line aero frames, tons of wheel choices [even more tire choices] and riders race everywhere from in the hoods to the tops to the drops. Assume that you want to test every setup from -15 to +15 deg of yaw at 3 degree increments, and suddenly you've got 3,000 setups to test.


Obviously, that's impractical, so you have to do with a few guidelines, such as faster frame = faster frame + rider.


Unfortunately, there are a few thing contrary to our guidelines: ie, a flat disc may be faster on a P3 [or other faired frame] than a lenticular disc. As such, the guideline of "faster frame + faster wheels = faster" may not hold true in all cases.


...


That said, the only money I've ever won is from finishing on the podium in a bike race, on my totally non-aero frame with non-aero wheels*, so none of this matters to me. I time trial on a 3rd hand P2K.


*: Externally routed square tubes with 24h 30mm training wheels ... and fast tires. ;)