It took more than 20 years, but, the cycling world has finally embraced the 650c wheel. Or, at least, one among the world's professional cyclists. Still, if you're a fan of the right wheel for each rider, that rider you wanted selecting 650c was the rider you wanted aboard them last week.
That one person is the new UCI Time Trial World Champion. It's diminutive Emma Pooley—she of the Cervelo Test Team. All 5'2" of her.
Pooley rode a 48cm Cervelo P3 for her Worlds victory, her race covered by Cyclingnews.com. In the Cyclingnews article, Pooley is quoted as saying, "I had to move the saddle back a bit and move the bars up a bit because it wasn't within the regulations. I get a small exception because I am very short but it still wasn't quite right."
Cervelo's Gerard Vroomen confirmed Pooley rode a 650c-wheeled P3, and Pooley strained even on that bike to position herself sufficiently low, resorting to a 3T hinged stem that pointed aggressively downward (this is clear from the photo gallery on the Cyclingnews site).
Vroomen surmised that Pooley's saddle was positioned slightly too far forward of even the amount of morphological exception the UCI rules, and the commissaires, were prepared to give. Hence, her need to move the saddle back a smidge. There seems no rule that would require her to move her aerobars up—it's likely her reference to moving "the bars up a bit" is a response to the rule-required move of her saddle rearward.
Pooley's victory in Melbourne last week might be the permission slip short-of-statured professional cyclists need to give the smaller-wheeled bikes a second (or even a first) look.