Climbing and cooling During the development of this jersey, Castelli focused on low weight for climbing and good cooling properties for hot days, making it the perfect jersey for the Tour de France. Since Castelli didn't want to leave out aerodynamics completely, they used a similar cut to the extremely fast, new Aero Race 5.1 Jersey. The resulting jersey is extraordinarily airy, light and immediately became the new favourite jersey of the professionals. Castelli was somewhat surprised by the wind tunnel tests. This extra-light jersey achieved the same results as the Aero Race 5.0 Jersey, which means it was only 2 watts slower than the improved Aero Race 5.1 Jersey of the 2016 season - the fastest jersey Castelli have ever tested. So if you’re asked whether you want the best aerodynamics or light weight, the answer is easy: “Both, please."
good aerodynamics thanks to the cut of the Aero Race 5.1 Jersey's
Mesh arm cuffs with coarse cut edge
light front zipper
quick-drying Flusso 3D material (75g/m2) at the front and shoulders for low weight
Strada Pro 3D material on the back supports the hold of the bags and offers UPF 16 UV protection