The continuing push to develop aerodynamic optimization across every aspect of professional cycling drives Castelli to provide maximum advantage to their pro riders. Cyclists every where have the opportunity to wear the same technology, and while the benefits may be perceived differently, every rider (with a pro cyclist's body shape) gets to enjoy the incredible quality and performance of a piece such as the 103 gram Aero Race 5.1 Jersey FZ.

This full zip, race cut jersey has been tailored to be skin tight, creating the best surface for the aero fabrics. Improving on the class leading aerodynamics of the 5.0 version was a challenge Castelli embraced, but also with an eye to reducing weight and increasing comfort. The dominant forward facing fabric is Velocity Dry, super lightweight polyester blend that dries instantly. It releases moisture off the skin quickly, and as it cannot hold the moisture, the wearer never feels wet. It has 4-way stretch capability, which is managed by directionality of panels to control and perfect the anatomic form-fit. The structured, textured surface also happens to be the fastest material Castelli has developed and tested, offering a 2 watt gain over the previous version. The torso and chest panels, as well as the forward aspects of the arms, and the arc of the shoulder and neck all feature Velocity Dry.

The dominant back material of the Aero Race 5.1 FZ is another super light fabric, 3D Mesh. This fine mesh fabric also has controlled stretch, and allows the skin to breathe and release moisture without effort. Air flow assists in keeping the rider cool and dry, especially under max efforts on the hottest of days. The mesh is also found on the back of the arms and folded over with a wide cuff for the armbands, at the lower abdominal for maximum air movement, and is used for the pro-style rear 3-pocket structure. The fit, and ease of use overall rely on the full length YKK Camlock Zipper, a truly functional favorite for lightweight garments.

The fit itself is snug and lightly compressive, but more comfortable than the 5.0. Fabric transitions aren't noticeable. Castelli uses a light compressive band around the waist, which accentuates the cut and stretch, to gather the jersey close to the skin, while also supporting the lightweight rear pocket structure. A silicone gripper on the back hem keeps the jersey from riding up. Both the armbands and waist band have a soft feel against the skin. Make no mistake, this jersey is cut for lean, tapered cyclists. It is more forgiving than it's predecessor. but the essential cut is the same. If you are looking for a true pro-level jersey for the hot months of the year, you won't find a better performance product. And the fact that is that the materials dry so quickly and refuse to hold water, pro's even prefer this design on rainy or cool days when showers may interrupt the event. We recommend the use of sunblock applied to the skin before the jersey is put on. The Castelli Aero Race 5.1 Jersey represents the commitment of the company to attention to every detail and advantage a pro cyclists desires. You can enjoy this level of performance as well.