Bib shorts at this level live or die by their chamois, and the Free Aero Race S builds around Castelli's Progetto X2 Air Seamless pad—a single-density insert that eliminates the internal seams found in most multi-density designs. The seamless construction removes potential friction points during long saddle hours, while the perforated foam structure allows airflow through the pad itself rather than trapping heat against your skin. It's the kind of detail that separates bibs you tolerate from bibs you forget you're wearing.

The Free Aero Race S represents Castelli's race-focused bib short, sitting just below their top-tier Aero Race offerings while using much of the same construction philosophy. Castelli uses their Forza fabric across the main body panels—a compressive lycra with a textured face that manages moisture without the clammy feel of cheaper synthetic blends. The compression hits that productive middle ground: supportive enough to reduce muscle oscillation on long efforts, not so aggressive that you're fighting the shorts to breathe.

Panel construction follows Castelli's anatomic approach with the Giro3 leg band system eliminating the need for traditional silicone grippers. The bands use a wider, lower-compression design that stays in place through leg movement without creating the tourniquet effect that leaves red marks after four-hour rides. Flat-lock stitching throughout keeps seams from becoming contact points, and the mesh bib straps distribute tension across your shoulders without the thick elastic bands that turn into sweat collectors on hot days.... Read More