Belgian Johan Van Summeren won the 109th Paris-Roubaix earlier today and he did it with skinny seat stays and a jersey-shorts combo that's almost a skinsuit.
Roadies don't wear track-style skinsuits because they need jersey pockets, and they need to be able to pee (often while riding along). Skinsuits are therefore impractical, but undeniably fast.
Castelli has produced a half-way house, marrying a zip-through jersey to a pair of BodyPaint bibshorts.
This SpeedSuit is the "fastest bit of clothing ever created for road racing," said a press release from Castelli.
The SpeedSuit offers a "little bit of extra aerodynamic savings over a long period of time," said Castelli.
The claim is that, wearing SpeedSuits, the Garmin-Cervélo team can save 10-15 watts at 40 km/h.
The upper part is a full zip aero jersey with a slippy-through-the-air fabric on the shoulders to enhance aerodynamics. This aero jersey is then stitched three quarters of the way around the waist to Castelli's BodyPaint bibshort. The front of the short/jersey is overlapped allowing the rider to pee without peeling off the full suit.
As the jersey holds up the shorts, the SpeedSuit eliminates bib straps. And the three rear pockets in the figure-hugging top-half of the SpeedSuit holds contents more securely than a standard jersey.
There are two patents pending on the SpeedSuit, which is for pro riders only at the moment. Later in the year it will be available through the Castelli Servizio Corse Teamwear program, and in Castelli's Summer 2012 range.