The Castelli Men's Free Aero Race Kit Version Cycling Bib Shorts have been engineered as Castelli's premier race short. Their first Free Aero Race debuted in 2007 and has undergone continuous improvement as they developed new fabrics and construction methods and responded to feedback from their professional teams. Castelli designed the Free Aero Race to be fast by concentrating on helping you get the most out of your body and by optimizing aerodynamics. The other main goal in this short is comfort, because the pros will be riding 30,000 km per year, and a four-hour ride isn't even considered long. While the Free Aero Race short has been engineered for top-level racing, all its features make it an ideal short for any challenge.