Castelli Superleggera lightweight Bib-shorts are a must for training rides up mountains in the summer months. In order to remove weight while still providing durable bib-shorts that keep the seat pad in place, Castelli designed a new fabric. In place of a woven fabric, Castelli used a knitted fabric that weighs 30% less. In order to lighten the weight even more, they constructed a gradient fabric that becomes lighter the farther it extends down the leg. The heavier fabric at the seat area supports the rider while the lighter fabric at the end weighs a mere 90 g/m². This is more than 100 g/m² less than traditional shorts fabric. Despite the extremely light weight, the fabric is still durable and resistant to abrasion against the saddle. By decreasing the mass, the shorts will also absorb 30% less moisture when you are sweating. When racing up a climb, you will save close to 150 grams of weight. The bibs are made of a striped, highly breathable mesh which keeps bibs completely dry. The shorts are kept comfortably in place by flat stretchy woven leg grippers. The Progetto X² Air seamless seat pad is Castelli’s long-distance seat pad. The layer closest to skin is stretchy, seamless, and very soft against skin. The multi-layered padding underneath the skin layer has the right amount of padding in the right areas of the seat and it stays dry. The Progetto X² Air seat pad keeps a rider comfortable on 8+ hours on the bike.