Castelli’s latest Perfetto RoS 3 x Polartec AirCore foul-weather jacket is not technically waterproof, because apparently cyclists simply don’t ride in the rain as much as they used to. Castelli knows wet winter riding (remember the Gabba). But, they also know that, between indoor training, more reliable forecasting, and shifting climates, most cyclists simply don’t ride that often in the rain. So when it was time to update the Perfetto, and to make it more perfect, Castelli first prioritized breathability, and then weather-proofing. And it was harder than ever with contemporary environmental concerns. But working closely with Polartec, they developed an all-new 3-layer AirCore fabric that they both describe as a game-changer…
Why do cyclists need a new type of rain jacket?
(Photos/Castelli)
First off, that magic forever chemical PFAS is out, as it became abundantly clear how bad it is for the environment. So, every company has had to reimagine waterproof garments. And by starting over from scratch, Castelli took the opportunity to rethink what cyclists really need in weather-protective clothing. Staying dry is important, and keeping water out is a key aspect of that. But for cyclists who are working hard pedaling, staying dry inside is equally as important (if not more so).
Castelli developed this new top-tier cold and wet weather cycling jacket based on the idea, “How often do we actually ride in the rain?“
“Who me? I never ride in the rain”, was the answer from Steve Smith, Head of Cycling divisions for Castelli’s MCV Group parent. Smith explains there are 3 main reasons why fewer cyclists truly ride in the rain these days:
Indoor training tools have simply gotten better. They offer ever more engaging experiences, more accurate & controllable training environments, and often take up less time out of cyclists’ busy lives.
Weather forecasts are more accurate & more accessible. Most cyclists now have ready access to incredibly accurate weather data at their fingertips. With live radar data so easily to see on your phone, it’s easier than ever to tweak your ride time to avoid really getting wet. Maybe some days get turned into a Zwift day?
Climate change is reducing rain days. Sure, global shifts in climate aren’t really possible to simplify. But Castelli says their data analysis shows a decreasing number of rainfall days, even if rainfall intensities are increasing, and overall rainfall totals seem more stable.
Why ride outside in the rain when you don’t have to?
So, does that mean the new Castelli Perfetto RoS 3 a rain jacket made for cyclists who don’t ride in rain?
Yes, and no.
It is still a Rain or Shine jacket – that’s what the RoS stands for. And Castelli still names it Perfect, so it’s gonna still have to keep the rain out.
Just now, they prioritize breathability first, then add water protection as its secondary function. According to Castelli, making a fabric waterproof (weather protection) was easy. But then, making it also breathable without PFAS was always going to be extremely difficult.
Also, breathability itself is not so easy to quantify. There is already a static performance characteristic Moisture Vapor Transmission Rate (MVTR) industry standard. But real breathability really depends on controlled airflow through a fabric – whether climbing slowly or descending fast.
Preventing wind from getting in has usually been a core metric in weatherproof clothing, and often linked to water-resistance. But more airflow in can help get sweat vapor out, as long as it’s not too much.
Polartec AirCore: First breathability, then weather protection
The story of this new jacket is really the story of Castelli and Polartec working together to produce a new fabric that prioritized breathability, was still essentially waterproof, and of course, was more environmentally responsible.
At the core of the PFAS-free, 3-layer nano-membrane fabric is a unique process called electrospinning “where a hydrophobic proprietary polymer is pushed through a hypodermic needle charged at 20,000 volts. Under pressure, it emits a thin jet of microscopic filaments – approximately 100 times smaller than a human hair – which falls like snow to create an incredibly tight membrane that still allows air to permeate it.“
The resulting fabric is “essentially windproof” and “essentially waterproof”.
Windproof in the fact that it “feels” windproof enough that it does not affect your core temperature. But although imperceptible, it actually allows quite a bit of air to pass through in order to help evaporate sweat and move it away from the body. Smith described it as almost 10x as much air permeability as their Gabba.
Mostly waterproof in the sense that, its 5000mm water column performance rating is more than 6x the hydrostatic pressure of typical light rain or 2.5x the pressure of heavy rainfall, even if it’s just half the threshold of what some regulations allow to be defined as “waterproof”. The fabric is waterproof enough that Castelli still calls this a “Rain or Shine” jacket, and tapes the top shoulder seams to keep rain out.
More eco-friendly and high-performance
AirCore’s outer layers are knitted from 100% recycled polyester. The nano-fiber membrane at its core is made of a recyclable polymer, and is surprisingly stretchy for an “essentially waterproof” membrane – able to “be extended to over two times its original size“.
How breathable? The new Polartec AirCore rates 35,000 g/m²/24 hour
How air-permeable? 1.19 cubic meters per hour (m3/h), or 0.7 cubic feet per minute (CFM)
How waterproof? 5,000mm water column (compared to 10,000mm typically defining “waterproof”)
Optimal weather? dry or rain, temperatures ranging from 4-14°C (39-57°F)
“AirCore is a perfect example of our ongoing mission to merge cutting-edge performance with sustainability. Unlike traditional waterproof-breathable membranes that rely solely on moisture vapor diffusion, our advanced air-permeable laminate uses highly engineered nanofiber membrane technology to enable controlled airflow. This allows AirCore™ to actively maintain a dry microclimate during intense aerobic activity to keep the cyclist riding longer. In addition to setting a new paradigm in air-permeable and breathable, weather-resistant fabrics, it reflects our unwavering commitment to reducing the environmental impact of the textiles we create.”
– Ramesh Kesh, Polartec Business Manager
Castelli Perfetto RoS 3 x Polartec AirCore winter cycling jacket
To those who don’t know the jacket, the Perfetto is just the long-sleeve version of Castelli’s Gabba. That’s the original short-sleeved middle ground between a rain jacket & cool-weather jersey that made a name for itself in the pro peloton for early season racing (the black “jacket” you would see on many non-sponsored pros, wearing when the racing got wet and their own clothing sponsors couldn’t match its performance). It not only spawned a bunch of copies, but also genuinely a boost in competitor technical development to create more cycling clothing that was waterproof and truly breathable.
The new Castelli Perfetto RoS 3 jacket looks much like the previous generation, just with the all-new Polartec AirCore fabric. It gets a close performance fit, but lots of stretch for a comfortable body-hugging shape. It has long arms to ensure coverage over gloves, an extended drop tail to help keep your butt dry, and a tall collar to keep wind drafts out. Castelli gives the new Perfetto taped shoulder seams on the outside to keep real rain from getting in, a smooth 2-way YKK Vislon zipper with a flap to keep rain out from the front, and 2 front zippered mesh vents where you might expect to find slash pockets. Three rear pockets with drain holes provide plenty of storage since you will wear it more like a fall/winter jersey than a hardshell jacket. And reflective detailing helps you be seen.
First Impressions
(Photo/Cory Benson)
I only received the new Perfetto RoS 3 jacket a couple of days ago, and to further Castelli’s point, I have not ridden in the rain in the past 2 weeks. It has rained, but contrary to my typical habits this time of year, I have ridden a few times on Zwift to test out their new Clicks and a new trainer launching later today. Other than that, I rode on wet mountain bike trails, having timed my ride to avoid the actual rain showers. But I did get a chance to try the new Polartec AirCore on both a cool, dry evening ride as the sun set and a damp, early morning ride with heavy enough dew that my shoes and legs got wet – but not my butt under the extended tail.
My first impression is that the Castelli Perfetto RoS 3 feels much more like an aero long-sleeve jersey than a jacket. It is incredibly thin, nicely fitted, but doesn’t feel constricting. I’ve only ridden it down to about 12°C, which is near its upper limit (with just a mesh baselayer) up to ~17°, far warmer than I would ever even wear a long-sleeve. I was certainly comfortable at the cooler end, and did sweat, but cooled surprisingly quickly with the jersey jacket fully unzipped at the warmer end. Now, I just have to wait for cooler weather and some rain.
My size, made-in-Moldova L Mocha jacket weighs 252g and packs down a bit smaller than a 500ml bidon.
Castelli Perfetto RoS 3 x Polartec AirCore – Pricing, options & availability
The new Castelli Perfetto RoS 3 jacket is available now for $320 / 250€ in both men- and women-specific cuts, each with their own color options. Rich Red, Pool Blue, Mocha, and Light Black for men. Hibiscus, Pool Blue, Mango Mojito, and Light Black for women.
Polartec AirCore remains exclusive to Castelli (and their sister company Sportful) in the cycling world for the foreseeable future, but it will pop up in other outdoor sport clothing industries later this autumn into winter. As for Castelli & Sportful, each will launch more AirCore gear in the coming months. Think: anything that would benefit from breathable weather protection – from gloves to shoe covers to tights & more. We’ll keep our eyes peeled.