yeah but look at how far back and low the dummy is sitting :-) :-)

check out this pic of a fairly forward position...there's still apparently a fair bit of pedal exposed all around the stroke, no? ;-) (BTW, those are Time RXS pedals)

A lot of rear derailleur, too (albeit partially due to the camera angle).

Back of the napkin calcs: So if a frontal area decrease of even two rectangles of 5mm x 50mm is possible by switching pedal systems, we have a frontal area decrease of 0.00025 m^2 or 0.045% of the frontal area of a 0.55 m^2 frontal area cyclist. Assuming Cd does not change as the pedal systems are seeing generally turbuent air at low speeds in the wake of the shoe (past flow separation of the shoe), this could decrease total system CdA by that same 0.045% or ~0.010 m^2 (of 0.24 m^2 system CdA).

Okay -- so in theory, if you held a shoe in tangential 30 mph flow, you could realize this frontal area decrease and thus the significant drag savings. The thing I don't know yet is if the pedal and cleat system actually sees this kind of a situation enough to garner this aerodynamic savings. Any flow visualization to share?

0.0001 or 0.0002 m^2 seems more realistic by my estimation and there's no way you can measure that in a wind tunnel.

What's the precision of various wind tunnels? Is this generally advertised?

Texas A&M tunnel - http://lswt.tamu.edu/info.htm

.01 lb resolution, so likely no joy. CdA of .0001 at 30 mph is what, .01 N on it's own. So on the order of .002x lbf. Could of course have some better force balances, but still, .01 N is no way 33 seconds.

Strikes me that this is the key takeaway from all this- not that we shoudl all somehow mount speedplays with no adaptor plates to our shoes (very hard to do) but instead, we should smooth out our shoees sot he cleats dont stick out.

What did you use on this pic to aero-out the cleats?

Clyde

You mean like these shoes on which I'll be doing some field testing in a velodrome:



See here:
http://www.bont.com/...pages/bontcrono.html