The Castelli Alpha RoS 2 Light Women's Jacket is a high quality, high performance and comfortable three-season option that puts a significant dent in your wallet. It does do away with gilets or numerous baselayers though – it protects brilliantly in a wide range of temperatures and weathers.
There are so many winter jackets available these days the choice is overwhelming. Castelli alone has no fewer than seven long-sleeved jackets on its site, but I'd say the Alpha RoS 2 Light is the best 'all-rounder' option there. It works hard from early autumn through to spring, and needs very few additional bits of kit to support it.
The Alpha RoS 2 Light has a double layer build. Inside is the lightweight, insulating fabric known as ProSecco Strada. Outside, the front panels and sleeve fronts are made of Gore-Tex Infinium Windstopper 150, while the back and underarms are Nano Flex Xtra Dry for protection against rain.
Each layer has its own YKK zip – it looks a bit like you've got half a waistcoat sewn into the jacket. It's a strange idea to get used to; the rote action of jacket-on-jacket-off goes out the window.
Of the three Castelli jackets/jerseys I've been testing recently, this is by far the best fit for me. The cut is well thought out and, despite this being a winter jacket, it doesn't have that sense bulk or thickness you so often find.
In my size it gives a relaxed fit with a little room round the torso and down the full length of the sleeves (it's not me in the photos), which seems to promote ventilation and moisture transfer. While being generous, the cut is flatteringly feminine and the jacket doesn't budge or flap in any riding position. Consider sizing down if you like a very snug fit, though.
Sleeve and body length are both good. The cuffs are simple elastic affairs, and sit over a slim glove perfectly – bulkier winter gloves are happier over the top.
The wide, raw-edge elasticated waist is brilliantly designed, coming into its own when you're on the bike. It sits low at the front and has generous length at the rear. It simply doesn't budge; the elastic, coupled with a silicone strip, effectively forms a seal between the jacket and your tights/shorts. Despite the relaxed fit, I never once found it needed adjusting.
The neck line is high – perfect for really cold days – and warm enough you'll want it unzipped on mild days. There's a tongue of soft fleecy fabric that sits against the back of the neck, too. As a whole, the fit is engineered to keep the cold out and the heat in, and it does that very well.
Castelli recommends this for between 8-15°C. While I haven't had the opportunity to take it up to 15 degrees, I've had plenty of rides from around 12° to below the lower limit.
While I'm not a fan of no baselayer (in any weather), the Alpha RoS 2 Light easily functions without one on mild days; the torso is soft and comfortable against bare skin, although the sleeves are not so luxurious. Once the mercury hits single figures, a long-sleeved base layer was all I needed beneath. I found with this set-up I was comfortable down to near-zero. The jacket keeps off bitter wind chills brilliantly.
Castelli doesn't guarantee 100% waterproofing, but in light rain and showers the water beads off, the shoulder seams are sealed and the zip is waterproof. The Nano Flex Xtra Dry fabric on the back holds off showers too, but after 30 minutes of heavy rain it begins to feel damp (yet not cold).
I never sensed a build-up of moisture and have to admit to being surprised that, when took the jacket off after some pacier rides, there was significant moisture clinging to the jacket's interior... Still, the fabrics perform sufficiently well to keep me warm despite the build-up.
The three rear pockets are perfectly positioned for access on the move and generous in size, while a base insert means you can stuff them full and the pocket stretches – not the jacket. There's a fourth zipped pocket at the side for keys or money. For me, this is so much more accessible and functional than one sitting on top of another pocket.
I absolutely love this Fiery Red – top marks for visibility – but if you prefer more subtle colours it also comes in Rescue Blue, Savile Blue and – fantastically – Light Black.
The only thing missing from the Alpha RoS is a lower zip guard. Castelli's own tights have paid the price for this omission by bobbling up, though less delicate fabrics haven't been affected.
Quality and performance come at a cost, and the Alpha RoS 2 Light is no exception. It's still not the most expensive, though – Rapha's women's Classic Winter Gore-Tex Jacket will set you back a further £45, while Assos' UMA GT Ultraz Winter Jacket EVO is £290.
The Alpha RoS 2 Light is packed full of technology to keep you comfortable, warm and dry throughout a good chunk of the year. Yes, the price is high, but its versatility, quality and style are unquestionable.
Superb jacket for most conditions and three full seasons
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road.cc test report
Make and model: Castelli Alpha RoS 2 Light Women's Jacket
Size tested: Medium
Tell us what the jacket is for and who it's aimed at. What do the manufacturers say about it? How does that compare to your own feelings about it?
Castelli says: "Castelli's best jacket for mild conditions, with front wind protection, light insulation, maximum breathability, and water repellency to keep you dry in mist, light rain or spray from wet roads."
Tell us some more about the technical aspects of the jacket?
*GORE-TEX INFINIUM™ WINDSTOPPER® 150 fabric on front and sleeves for wind protection with high breathability and effective rain protection
*Nano Flex Xtra Dry on back for more ventilation allows heat and sweat to escape while shedding rain thanks to a nanotechnology water-repellent finish
*Alpha double-layer construction separates windproof layer from insulation layer, allowing better ventilation management
*Inner layer in ProSecco Strada for lightweight insulation with effective moisture management
*Double YKK® Vislon® front zippers
*Front zippered pocket
*3 rear pockets with reflective laser-cut drain holes
*Raw-edge waist lies flat and moves with you
*8°-15 °C / 46°-59°F
No signs of weakness in the construction or fabrics.
Keeps off showers and light, persistent rain.
I'd say size down if you're on the cusp.
How easy is the jacket to care for? How did it respond to being washed?
Fine in the advised 30 degree cycle.
Tell us how the jacket performed overall when used for its designed purpose
Brilliant in a range of temperatures that actually exceeds those suggested. Add the support of a single base layer (in colder weather) and you're fully protected from bitter winds and light rain from around 4 to 14°C.
Tell us what you particularly liked about the jacket
Tell us what you particularly disliked about the jacket
Lack of lower zip guard.
How does the price compare to that of similar products in the market including ones recently tested on road.cc?
This is in the mid to upper range. It's still not the most expensive, though – Rapha's Women's Classic Winter Gore-Tex Jacket will set you back a further £45, while Assos' UMA-GT-Ultraz is £290. More thrifty alternatives include dhb's Aeron Rain Defence Polartec Jacket for £130 or Lusso's Aqua Repel Jacket at £134.99.
Did you enjoy using the jacket? Yes
Would you consider buying the jacket? Yes
Would you recommend the jacket to a friend? Yes
Use this box to explain your overall score
It's versatile, stylish, functional and very effective – it's only really lacking a lower zip guard!
About the tester
I usually ride: Road My best bike is: Carbon road.
I've been riding for: Over 20 years I ride: Most days I would class myself as: Expert
I regularly do the following types of riding: commuting, touring, club rides, general fitness riding, Getting to grips with off roading too!
Emma’s first encounters with a road bike were in between swimming and running. Soon after competing for GB in the World Age Group Triathlon Championships in Edmonton in 2001 she saw the light and decided to focus on cycling.
After a couple of half decent UK road seasons racing for Leisure Lakes, she went out to Belgium to sample the racing there and spent two years with Lotto-Belisol Ladies team, racing alongside the likes of Sara Carrigan, Grace Verbeke, Rochelle Gilmore and Lizzie Deignan. Emma moved from Lotto-Belisol to Dutch team Redsun, then a new Belgian team of primarily developing riders, where there was less pressure, an opportunity to share her experience and help build a whole new team; a nice way to spend her final years of professional racing.
Since retiring Emma has returned to teaching. When not coercing kids to do maths, she is invariably out on two wheels. In addition to the daily commute, Emma still enjoys getting out on her road bike and having her legs ripped off on the local club rides and chain gangs. She has also developed an addiction to touring, with destinations including Iceland, Georgia and Albania, to mention just a few. There have also been rare sightings of Emma off-road on a mountain bike…