Castelli claims that while its women's clothing is typically designed from the ground up for, well, women, the Free Aero Race 4 Bib Short is designed specifically for racing. That being said, it's built using minimalist construction, one that focuses on aerodynamics and also comfort, as racing requires long hours in the saddle, both during training and on race day. It features some new details making subtle improvements over its already best-selling short. It uses a new leg gripper that still features a lie-flat raw-cut edge but now has vertical silicone stripes to keep it in place without restricting stretch. New fabrics allow for better print quality and Castelli also updated the seams to improve the fit and give the short an even better look. It also re-engineered the bib straps with new fabrics and construction so you stay cooler and it lies flatter and is more durable. Final updates include a new Progetto X2 Air Seamless insert and its one of the softest surface fabrics we've ever felt in a chamois.