The Castelli Sanremo 2.0 Speed Suit provides the energy-saving aerodynamics of a skin suit with some practical details. Skin suits are obviously fast, but they aren't workable for road racing for a couple of reasons. First, they have no pockets and, perhaps more importantly, it's tough to make a pit stop without completely undressing. So Castelli created a new and improved aero jersey with a full zip and new fabrics and then stitched it to a Body Paint bibshort. Interestingly enough, Johan Van Summeren road the Sanremo Speed Suit to its first Professional victory in the 2011 Paris Roubaix.
The jersey portion and short portion overlap on the front for full coverage, but leaving the front unstitched allows for nature breaks even from the bike. The 3 rear pockets are securely held in place in all conditions, including when fully loaded. The main aero benefit comes through improved airflow around the torso by keeping the sides of the jersey in tension. Castelli was able to remove the bib straps, improving comfort and allowing even more cooling when fully unzipped.
The Sanremo 2.0 Speed Suit employs the Progetto X2 chamois that, like the shorts, is designed to disappear beneath the rider. It has two distinct components. A skin care layer is bacteriostatic, soft, stretchy, seamless and is designed to prevent chafing. The cushioning layer features variable thickness with extra viscous padding beneath the sit bones and perineum.