Particularly for TDF stage 17 consisting of 3 incredible climbs, I don't see the pro were really using those very low profile wheels, something like early yrs Marco Pantini bike, 25mm or lesser profile. I sensed av. profile they used for stage 17 were 35 or 40mm. I read articles that weight is not the most important factor for speed as riding on a course of ups and downs will average out. Yes, low profile will create more turbulence ard the wheel, but the disadvantages will be negated riding in a peloton. If they are paranoid to throw away gels during climb which is a mere grams to reduce weight, why not use those very low profile wheel which will lighten at least 500 to 600g.