Maximum lightness and technology to survive the summer: we tested the Castelli Climber’s A/C with the Superleggera shorts

With temperatures rising each season, the choice of clothing is no longer a minor detail. We have been riding with Castelli's summer set consisting of the Climber's A/C Jersey and the Superleggera Bibshort, two garments developed for intense heat and many hours on the bike. The jersey is rated for a range of 22 to 40 degrees and the bibshort from 20 to 40, so on paper, it is a kit to use precisely now.

Test of Castelli Climber's A/C and Superleggera: freshness and lightness for the height of summer

Both garments share a race fit and the approach of minimizing fabric and weight without compromising functionality. Together, we are talking about 319 grams between the jersey (157 g) and the bibshort (162 g), figures that place them among the lightest in the catalog of the Italian brand.

Climber's A/C Jersey: 3D mesh with aerodynamic work behind

The Climber's A/C is born from Castelli's development program with its professional riders, who requested a jersey that would keep them cool during mountain stages without sacrificing aerodynamics. The placement of the fabrics and the construction of the seams are defined using CFD, the same methodology that the brand applies in its Aero Race 8S, but here with the most ventilated mesh fabrics that Castelli has been able to use.

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The front features Flusso 3D fabric and the back StradaPro 3D, aimed at improving breathability in the area most exposed to the sun. The sleeves reach the elbow, are elastic, and finish with a raw cut, without silicone bands. The shoulder construction follows the brand's Airflow pattern, the zipper is a YKK Vislon, and the waistband incorporates a perimeter elastic with retention pockets to prevent the load from shifting the garment. The back fabric blocks 90% of UV rays, although the garment's certification is UPF 13, a detail to consider if you spend many hours in the sun.

The declared weight is 157 grams and the fit is distinctly race: it is a garment designed to fit snugly to the body, so it is advisable to fine-tune the size within the available range, from XS to 3XL.

Superleggera Bibshort: woven fabric and gradient

The Superleggera is the lightest bibshort that Castelli has made, and what’s interesting is how it has achieved that weight. Instead of the usual knitted fabric, the brand has developed a woven fabric that reduces weight by 30% while maintaining the same level of muscle support and without transparency. Based on that, the leg fabric is gradient: it progressively lightens down to 90 g/m² at the end of the leg, compared to approximately 220 g/m² of a conventional bibshort.

The weight saving is about 48 grams dry, but the most relevant data comes with sweat: this fabric absorbs 30% less moisture, so in a long ascent in heat, the real saving compared to a conventional bibshort exceeds 150 grams according to Castelli. The brand warns that the abrasion resistance is designed for contact with the saddle, not for sliding on asphalt, which is logical in a garment of this weight.

In the rest of the construction, there are no cutbacks: the chamois is the Progetto X2 Air Seamless, the highest range from Castelli, seamless and aimed at long distances. The mesh straps come from the Free Aero Race 4 Bibshort, with a minimalist construction that helps keep the body cool, and the leg ends in a flat elastic band with visible Lycra to ensure adherence. The declared weight is 162 grams and the temperature range is from 20 to 40 degrees.

Our experience on the road

On the rides we have done with the set during these hot weeks, the dominant feeling is exactly what it promises: it is a cool kit for this time of year. The mesh fabrics of the jersey allow air to flow through clearly, and the bibshort, with its very low weight in the leg, contributes to a significantly lower thermal sensation compared to a conventional summer set. On days when the thermometer rises, that difference is appreciated from the first kilometers.

The other point that confirms expectations is the quality of construction. Castelli has been in the high-end cycling clothing market for years, and this set reflects that: seams, finishes, and details are at the level expected for its price. They are not cheap garments, but they also do not convey any doubt in construction.

The Climber's A/C and the Superleggera form a very specialized set, and therein lies both its virtue and its limit. For riding in heat —which is exactly what they are made for—they deliver: real freshness, minimal weight, and Castelli quality in every detail. In return, one must accept that they are garments with a very narrow usage range, and below 20-22 degrees, they fall short on protection, the race cut requires getting the size right and the bibshort, due to its own weight, is not the option for those prioritizing durability in a fall. The UPF 13 of the jersey also advises solar protection on the longest days.

Technical specifications and discounted price

The Climber's A/C Jersey is priced at 120€ and is available in four colors, from XS to 3XL. The Superleggera Bibshort has an official price of 220€, although at the time of publishing this test it is discounted by 30% on the Castelli website, bringing it down to 154€, in black or Belgian Blue and also from XS to 3XL.

Castelli Climber's A/C Jersey. Weight: 157 g. Temperature range: 22°C - 40°C. Fit: race. Fabrics: Flusso 3D on the front and StradaPro 3D on the back, with fabric and seam placement based on CFD. Airflow shoulder construction. Elastic sleeves up to the elbow with raw cut edges. YKK Vislon zipper. Waist elastic with retention pockets. Solar protection UPF 13 (the back fabric blocks 90% of UV rays). Sizes: XS to 3XL. Colors: Deep Bordeaux/White, Belgian Blue/Winter Sky, Vivid Orange/Smoky Gray, and Silver Gray/Smoky Gray. Price: 120€.

Castelli Superleggera Bibshort. Weight: 162 g. Temperature range: 20°C - 40°C. Fit: race. Woven fabric (not knitted) with 30% less weight, elastic and gradient in the leg: down to 90 g/m² at the end of the leg compared to 220 g/m² of a conventional fabric. Absorbs 30% less moisture. Progetto X2 Air Seamless chamois. Mesh straps with minimalist construction (Free Aero Race 4). Leg finish with flat elastic band with visible Lycra. Sizes: XS to 3XL. Colors: black and Belgian Blue. Price: 220€ (currently 154€ with the summer discount).

More information on the Castelli website.