141 grams. That's what a size Large Castelli Superleggera Bibshort registers on the scale, and the moment you pull a pair on during a 95-degree ride the number starts to make sense — the fabric feels closer to a technical shell than to traditional Lycra. Castelli has been chasing lightweight short design since 2011, kept hitting the same durability wall, and eventually stepped back to engineer a new woven fabric rather than thinning out a knit. The result is a hot-weather-specific bib built around a graduated-ventilation stretch woven that gets progressively lighter as it runs down the leg, finishing at roughly 90 g/m² compared to the 220 g/m² typical of standard short fabrics.
The shift from knit to woven construction is what unlocks the weight savings. Castelli claims a 30% reduction versus a comparable knit without losing support or going transparent, which is the trap most ultralight shorts fall into. What you get is a short that saves about 48 grams dry, but the payoff shows up when you're sweating. The woven fabric absorbs roughly 30% less moisture than typical short material, which means on a long climb in the heat you're carrying about 150 grams less than you would in a conventional bib. That's the real argument for the Superleggera: not the weight sitting in the drawer, but the weight you're not hauling up the climb.
Bibs and chamois don't get shortchanged in the pursuit of grams. Castelli uses the same Progetto X2 Air Seamless seat pad found in the Free Aero RC S and Premio EVO — a perforated top layer against the skin, seamless integrated padding, and a viscous insert at the sit-bone contact zones. The upper draws on the striped mesh bib construction from the Free Aero Race 4, which keeps the straps disappearing into the background even in humidity. An integrated gripper elastic with exposed Lycra holds the leg without the silicone-band pinch point that tends to migrate on lightweight fabrics, and the tone-on-tone embossed logos and stretch silicone scorpion heat transfers keep the look quiet.... Read More
One sizing note worth flagging: Castelli runs an Italian race cut, so these fit tighter than most American brands and the bib straps are cut short. If you're between sizes or taller than 6'0", size up. The recommended temperature window is 68°-104°F / 20°-40°C, and honestly that lower bound is generous — this is the short you reach for when the forecast turns brutal and everything else feels like too much fabric.
