Castelli Free Aero Race S – The competition bib shorts designed to make you faster

Optimized aerodynamics. Long-distance comfort. A fit designed for performance.

Discover the Castelli Free Aero Race S Men's Bib Shorts, premium bib shorts from the Rosso Corsa collection, designed for demanding cyclists seeking the best balance of speed, comfort, and support.

Developed after countless hours of wind tunnel testing, they combine Forza2 aerodynamic fabric, a Progetto X2 Air Seamless chamois, and minimalist breathable straps to support your intense training, long rides, and races.

Castelli reports a 3% reduction in aerodynamic drag coefficient (CdA) thanks to fabric optimization in its test conditions.

Bib shorts designed to turn every detail into an advantage on the road.

Key features of the Castelli Free Aero Race S

• Aerodynamic Forza2 fabric: stretchy material that hugs the body and moves with your pedaling.

• Up to 3% CdA reduction reported by Castelli: optimized wind tunnel design.

• Progetto X2 Air Seamless chamois: premium comfort for long rides.

• Flat, minimalist straps: precise support without unnecessary bulk.

• Breathable mesh back: promotes heat dissipation.

• Silicone grip bands: prevent the leg cuffs from riding up.

• Race fit: performance-oriented close fit.

• Integrated back pocket: extra storage for a small accessory or race radio.

• UPF 50+ sun protection: fabric designed for summer rides.

• Temperature range of 15 to 35°C: ideal for cycling in mild to hot weather.

Forza2: fabric designed for aerodynamics

The Castelli Free Aero Race S uses Forza2 stretch fabric, developed to combine freedom of movement with aerodynamic performance.

Its construction hugs the contours of the body to minimize wrinkles and unwanted fabric movement as speed increases.

Unlike fabric that is too compressive, Forza2 retains enough stretch to naturally follow every pedal stroke.

The result: a precise fit and a supportive feel suited for sustained efforts.

An aerodynamic advantage measured in the wind tunnel

With the Free Aero Race S, Castelli does more than just focus on comfort.

The Italian brand optimized the fabric structure and the bib shorts' fit after wind tunnel testing.

According to Castelli, this design provides a 3% reduction in CdA under its test conditions.

This improvement refers to measured aerodynamic drag and does not directly translate to a 3% gain in speed, which depends notably on the cyclist's position, power output, and riding conditions.

A real asset for competitors seeking to optimize their equipment down to the smallest detail.

Progetto X2 Air Seamless: long-distance comfort

The Free Aero Race S features the Progetto X2 Air Seamless chamois, one of Castelli's premium references.

Designed to support long hours in the saddle, it combines a soft contact surface with a support structure suited to the demands of pedaling.

Its seamless design at the contact surface helps minimize friction and pressure points.

It offers an excellent level of comfort during both long endurance rides and intense training.

For cyclists who spend many hours in the saddle, the quality of the chamois is an essential criterion.

Minimalist straps and breathable back

Castelli designed flat, lightweight, stretch straps to provide effective support without adding unnecessary material.

The breathable mesh back promotes airflow and helps limit heat buildup during exercise.

This construction is particularly appreciated during summer rides and high-intensity competitions.

The bib shorts stay well positioned while maintaining a lightweight feel.

Silicone grip bands: stability with every pedal stroke

The leg cuffs feature silicone grip bands.

They keep the fabric properly positioned on the thighs without riding up excessively while pedaling.

This stability contributes to overall comfort and helps maintain a consistent fit throughout the ride.

It also helps maintain the bib shorts' aerodynamic fit.

Race fit: a second skin for competition

The Free Aero Race S features a Race fit, which is closer-fitting than that of traditional cycling bib shorts.

This design minimizes excess material and optimizes the fabric's position on the body.

It is particularly suited to cyclists accustomed to close-fitting technical clothing and those seeking performance-oriented equipment.

The stretch fabric still allows for good freedom of movement in a cycling position.

A practical and discreet back pocket

The Free Aero Race S features a small back pocket.

Originally designed to hold a race radio, it can also be used to carry a small, lightweight accessory.

A functional detail that complements its competition-oriented design.

UPF 50+ sun protection for summer rides

The bib shorts' fabric is UPF 50+ certified, helping to protect covered areas from ultraviolet rays.

An interesting feature for long rides in the sun and summer training.

Ideal bib shorts for 15 to 35°C

Castelli recommends the Free Aero Race S for temperatures between 15 and 35°C.

It is particularly suitable for:

• Road cycling competitions.

• Gran fondos and mountain races.

• Long endurance rides.

• Intense training and threshold sessions.

• Hot-weather cycling camps.

• Triathletes' cycling preparation.

• Fast rides where aerodynamics are as important as comfort.

Free Aero Race S or Espresso: which bib shorts should you choose?

The Castelli Free Aero Race S prioritizes competition, aerodynamics, and a particularly close Race fit.

The Castelli Espresso is aimed more at cyclists seeking excellent everyday comfort, with a more accessible and versatile fit.

Both models feature a premium chamois, but their philosophies differ: aerodynamic performance for the Free Aero Race S, versatility and comfort for the Espresso.

Why choose the Castelli Free Aero Race S from Triathlon Store?

At Triathlon Store, we select equipment for cyclists and triathletes who want to improve, gain comfort, and optimize their performance.

The Castelli Free Aero Race S combines the qualities expected of premium bib shorts: aerodynamic fabric developed in the wind tunnel, a long-distance chamois, and precise support.

Whether you are preparing for a gran fondo, a mountain camp, or the long rides in your IRONMAN preparation, it is an excellent choice for riding fast and for a long time.

Castelli Free Aero Race S: every detail counts when performance becomes a priority.

FAQ

What is the difference between the Castelli Free Aero Race S and the Free Aero RC?

The Free Aero Race S is an aerodynamics-focused evolution, with a Forza2 fabric optimized in the wind tunnel and a Race fit. It retains a Progetto X2 Air Seamless chamois for long distances.

Are the Free Aero Race S bib shorts suitable for rides of more than four hours?

Yes. Its Progetto X2 Air Seamless chamois is designed for long-distance comfort, even though it also depends on the saddle and the rider's body shape.

Is the 3% aerodynamic gain real?

Castelli reports a 3% reduction in the aerodynamic drag coefficient (CdA) during its tests. It is not a guaranteed gain of 3% in speed or power for every cyclist.

Which size should you choose?

The Race fit is close-fitting. It is recommended to follow the Castelli size guide and to take into account your inseam and hip measurements.

Can you use these bib shorts to prepare for an IRONMAN?

Yes, for cycling workouts and long preparation rides. In triathlon competitions, a tri-suit suited to all three disciplines is generally more practical.

What is the difference between the Free Aero Race S and the Espresso?

The Free Aero Race S prioritizes aerodynamic performance and a competition-oriented fit. The Espresso is more focused on everyday comfort and versatility, with a more accessible fit.

Both models feature a premium chamois, but their philosophies differ: aerodynamic performance for the Free Aero Race S, versatility and comfort for the Espresso.

Why choose the Castelli Free Aero Race S from Triathlon Store?

At Triathlon Store, we select equipment for cyclists and triathletes who want to improve, gain comfort, and optimize their performance.

The Castelli Free Aero Race S combines the qualities expected of premium bib shorts: aerodynamic fabric developed in the wind tunnel, a long-distance chamois, and precise support.

Whether you are preparing for a gran fondo, a mountain camp, or the long rides in your IRONMAN preparation, it is an excellent choice for riding fast and for a long time.

Castelli Free Aero Race S: every detail counts when performance becomes a priority.

FAQ

What is the difference between the Castelli Free Aero Race S and the Free Aero RC?

The Free Aero Race S is an aerodynamics-focused evolution, with a Forza2 fabric optimized in the wind tunnel and a Race fit. It retains a Progetto X2 Air Seamless chamois for long distances.

Are the Free Aero Race S bib shorts suitable for rides of more than four hours?

Yes. Its Progetto X2 Air Seamless chamois is designed for long-distance comfort, even though it also depends on the saddle and the rider's body shape.

Is the 3% aerodynamic gain real?

Castelli reports a 3% reduction in the aerodynamic drag coefficient (CdA) during its tests. It is not a guaranteed gain of 3% in speed or power for every cyclist.

Which size should you choose?

The Race fit is close-fitting. It is recommended to follow the Castelli size guide and to take into account your inseam and hip measurements.

Can you use these bib shorts to prepare for an IRONMAN?

Yes, for cycling workouts and long preparation rides. In triathlon competitions, a tri-suit suited to all three disciplines is generally more practical.

What is the difference between the Free Aero Race S and the Espresso?

The Free Aero Race S prioritizes aerodynamic performance and a competition-oriented fit. The Espresso is more focused on everyday comfort and versatility, with a more accessible fit.