The issue of the aero advantage of modern wheels, starting at 22 mph is and interesting one to me. I consider myself a pretty average rider in terms of speed. Those that train regularly (but sanely) to be fast, all seem to have a speed of about 22-23 mph when riding solo and working hard but not TOO hard on level ground without a headwind. (Fastest cruising speed). This is my speed and conincidently it seems to be the speed of older guys who seem a little out of shape, younger guys who are in shape, women who are in very good shape but not younger guys who seem to be training everyday or taking on illegal substances (those people fast cruise at 25). In other words, for all intents, lots of people have a fast cruising speed of 22 to 23 in my experience. I get to that speed just by thinking circles or bending my arms or concentrating on my breathing but the moment that I want to go 24, either my legs or my lungs burn. When I want to catch up to some "lone rider", invariably I have to do 24 which is hard for me and then I draft off him when I catch up, and miracle of miracles.. he's dong 22.5 or something close.
All my friends which have to work like balls to solo cruise at 24, have no problem drafting in a large group at 26 to 28, in fact we all report the same thing, while working in the aerodynamic shelter of a big group often you don't even have to pedal all the time to maintain 26 or 27. I imagine that it's not just the aerodynamic effect on the body but on the wheels as well. If modern wheels offer any kind of aerodynamic advantage it must be at higher speeds which most people find the sticking point anyway. (22 mph or so). So from what people have been saying on this list over the past day, I would have to concur. Modern wheels may impart some advantage, but it would be felt at higher speeds than where most people find a speed barrier anyway. I find that just about everybody finds 22 or so "the wall" when riding solo whether they are on a tri bike, an old classic or something ultra modern made out of epoxy and resin... whether they are carrying four water bottles or none... whether the rider is wearing lycra or wool...whether sitting on old Brooks or new Selle.
There seem to be other limits to cycling efficiency as well. On a normal classic bike, if one is in exceptional condition, at their prime, highly gifted, riding on a track and working as hard as they can for one hour they will find speeds close in the high 20's or 30 to be "the wall" riding solo. Given disk wheels, tri bars, a skin suit, an aero helmet, modern pharmaceuticals and or whatever else, even the great past records of the past will be broken by people who may even be less talented than Merckx or Ritter. Example ;(Moser and those that follow).
It must be at speeds in the mid to high 20's when the aero effect of fewer spokes and aero section wheels kick in. For most of us the overall problem is overcoming the challenge of moving our bodies through the "air wall" at 22 or so, and this occurs long before any advantages of decreased spoke turbulence can be found.
Garth Libre in Miami Fl.