If you watched the Tour de France Team Time Trial earlier today, you may have seen Bobby Julich, the American rider on Team CSC, wearing a Camelbak hydration system. This is the first time I ever saw a rider wearing a hydration pack during a Tour stage. But, it was obvious and unusual enough to be noted by Outdoor Life Network analyst Paul Sherwin who said:
....That's Bobby Julich on the front. You can see that straw just sticking in front of his skinsuit there. That's to a pack on his back, the Camelbak, which is filled with liquid. Keeps himself topped up throughout the course of the event.
Julich carried the Camelbak inside his skinsuit, which means that the suit had to be fitted with him wearing a full hydration pack. It did not look like the Camelbak affected Julich's aerodynamics, as I would have expected. It appeared that the bladder was positioned directly behind the point of his helmet when he is in riding position on his time trial bike.
I don't ride with a Camelbak myself, but I think it's something worth looking at again if a pro cyclist wears one in a Tour de France time trial. He probably thinks that the drag induced by reaching for a water bottle, bringing it to his mouth, drinking from it, and returning it to the bottle cage is more than the slight increase in drag associated with wearing the Camelbak.
It will be interesting to look carefully at other Tour riders to see if any more of them are using hydration systems.
Update: According to Camelbak, Bobby Julich and David Millar both wore Camelbak Race Vest hydration systems in the Stage 9 time trial from Lorient to Lanester in 2002. It's surprising then that the 2004 Tour de France TTT is the first time I've seen indications that a rider is wearing one.