Review of the new Castelli Do.Di.Ci jacket

Castelli, a specialist in technical cycling apparel, built its reputation on iconic models like the Gabba jacket, launched in 2013 and revolutionary for its balance between protection from the elements and breathability in wet conditions. Today, the Do.Di.Ci jacket – a name inspired by the Italian word dodici, meaning twelve, in reference to its breathability being twelve times greater than previous models – is a logical evolution within the Fall/Winter 2025/2026 range. Positioned as a model derived from the Gabba, it specifically targets intense rides in dry and cool conditions, freed from the waterproofing constraints that weigh down models like the Perfetto RoS 3 or the Alpha. We have already tested it.

By Guillaume Judas – Photos: ©3bikes.fr

Within an already extensive catalog, the Castelli Do.Di.Ci stands out for its focus on intense training in the cool and windy conditions of early autumn. Developed in partnership with Ittai, an innovator in laminated membranes, it responds to a growing demand from riders who use the Gabba outside its initial scope: sustained efforts without rain, typical of conditions encountered in October and November or March and April. Available in men’s and women’s versions, with a short-sleeve variant, it is aimed at road and gravel enthusiasts who refuse to compromise between warmth and sweat wicking. Launched at the end of September 2025, it embodies Castelli’s philosophy : prioritizing engineering to save watts, without sacrificing sleek Italian aesthetics.

Ristretto, the technology that breathes

At the heart of the Do.Di.Ci is Ristretto technology, a PFAS-free laminated fabric designed for controlled air permeability: 3 cubic feet per minute (approximately 85 liters), the highest in Castelli’s 2025 range. Unlike Gore-Tex or Polartec membranes, which often top out at 0.7 cubic feet/min, Ristretto acts as an intelligent filter: it blocks 99% of the wind while allowing a minimal airflow that draws sweat from the skin surface, promoting evaporation without excessive cooling. This engineering, the result of a collaboration with Ittai, relies on a highly stretchable multi-layer structure (elastane and recycled polyester) that offers four-way elasticity for an anatomical fit without constraint.

In terms of construction, the jacket features a very fitted cut: seams reduced to the bare minimum to minimize friction and weight (only 213 g in size S, compared to 80 to 100 g more for a long-sleeve thermal jersey). The asymmetrical collar rises quite high to prevent air intrusion. For the same reason, the zipper is lined on its inner side.

The rear pockets are well-fitted against the back, maintaining access to their contents without compromising aerodynamics. A long reflective strip at the bottom of the pockets is also noticeable, for visibility. The DWR (durable water repellent) treatment is light, prioritizing breathability over waterproofing – a deliberate choice for optimal use temperatures of 8 to 15°C. In summary, the Do.Di.Ci is not absolute protection against winter harshness, but a catalyst : it transforms perspiration into a thermodynamic advantage, and proves ideal for sustained pace rides.

In terms of colors, the Do.Di.Ci remains understated with four versions: black, red, purple, and mocha, the latter three being much cheerier as the days get darker. Note that, as often with Castelli, the finish is of very high quality, which is still the minimum given the product’s high price, at nearly 230 €.

A well-fitted cocoon for a dynamic autumn

Tested on several rides in typical autumnal conditions (10 to 15°C with a moderate but ever-present wind), the Do.Di.Ci revealed exemplary consistency with its technical specifications. The close-to-body fit is unforgiving: without a crease in an aerodynamic position, it hugs the torso like a second skin, eliminating any parasitic flapping that could dissipate precious watts. But beware of small mid-season excesses: the jacket is much tighter than the latest Perfetto RoS 3, and might reveal some bulges. If you have any doubts about the prominence of your beer belly, you can easily opt for one size up from your usual size. Beyond the aesthetic aspect, the Do.Di.Ci offers fluid freedom of movement for changes in position on the bike, without excessive chest compression when the pace truly accelerates and breathing with it.

Thermal comfort shines within its target window: between 10 and 15°C with moderate wind chill, the Do.Di.Ci maintains a stable body temperature, wicking away moisture without chills. With a short-sleeve base layer (merino type), it provides the sensation of a light long-sleeve jersey. This is just enough unless you expect to finish your ride under the midday sun; with a long-sleeve thermal base layer, the jacket is less comfortable around the arms, but proves entirely adaptable to prolonged efforts without overheating. Rapid drying – less than 20 minutes after a light shower – reinforces this versatility, making it ideal for changing microclimates.

However, the lack of waterproofing is confirmed: the DWR repellency repels isolated drops, but sustained rain (tested for 10 min under a heavy shower) saturates the fabric surface, without deep penetration but with increasing discomfort. The high collar excels against frontal winds, limiting infiltration – a crucial detail on large, exposed flat sections. Overall, the Do.Di.Ci excels in cool but dry conditions, transforming intense rides into breathable and dynamic experiences.

Brilliant for the mid-season, perfectible for winter 

The Castelli Do.Di.Ci Jacket captivates with its surgical precision: a very high level of breathability that unleashes autumnal intensities, a very fitted cut, and progressive adaptability depending on the chosen base layer, making it a cornerstone of equipment for autumn or mid-spring. Its role is appreciated for those weather windows where the cold nips without biting, allowing for hard riding without an excessive wardrobe. At 230 €, it justifies its high-end price with its race fit and unbeatable weight, but falls short in its protection limit: below 10°C, it lacks insulating depth, and its lack of waterproofing makes it vulnerable to rainy whims. For passionate cyclists seeking a “spiritual” jacket for dry and crisp days, it’s a masterpiece; for winter or the risk of rain, it’s better to choose the Perfetto.

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