Castelli Alpha RoS Jacket

As an all-in-one winter jacket, the Castelli Alpha RoS is hard to beat. The Italian brand really means it when it calls it the 'Rain or Shine' (RoS – geddit?) jacket, and there's plenty of insulation for when the mercury falls.

• Pros: Feature-packed, warm, breathable, great fit
• Cons: Wickedly expensive, care needed when washing

After living with the Alpha RoS jacket for the past month or so when temperatures have dropped well into single figures at times, it has shaken up my perception of how I should dress for this coming winter.

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I've always been a layering kind of guy – donning baselayers, jerseys and jackets in varying combinations to achieve the optimal solution when I head out on cold mornings. It's a faff, and usually wrong by the time I get back in, when either the temperature has risen or it hasn't rained as predicted.

You're probably all familiar with that story in some way or another, but if there's one product that I've reviewed in recent times that can legitimately claim to do it all in deep winter, it's the Castelli Alpha RoS jacket.

It has a two-piece construction – a technical outer layer made from Gore Windstopper 150 fabric, bonded to a fleece inner lining that covers the core. In truth, when I first donned it for the pre-test photoshoot it looked and felt like a bit of an over-complicated and messy design, but the fact is it takes a lot of the complication out of winter layering, and does it to a level that makes the eye-watering £275 asking price bearable, if not quite great value.

Worn with the 'hatches battened down', so to speak, it's a superb cold weather solution. Worn over the top of just a summer mesh baselayer, it can easily handle 3-5°C, and I actually found myself unzipping the outer fabric zip in order to get a little extra cooling down my front at times despite the breathability of the outer.

The other way to increase cooling is to either partially or fully unzip the inner lining, allowing more airflow and the Gore outer fabric to do more moisture wicking. You can't take out the lining, so you can't convert the jacket into what would more or less amount to a Perfetto jersey; I always kept it partially zipped in some way to avoid the risk of it bunching up on my back, which meant that when temperatures were getting up beyond 6-7°C, it really was too heavy for the conditions.

Assuming you keep it back for the really cold weather, though, it's brilliant, and feature-packed for the job. The collar is tall and articulated with a fleece backing, the sleeves long and cuffs slim to create a seal from the wind, and a dropped tail for additional protection. That tail is elasticated and figure-hugging too, with a tacky Castelli-branded gripper underneath to ensure it sticks in place over your bibs.

The body is nicely slim without being restrictive – we had a large on test, so that's about right even with Castelli's traditionally small sizing – and doesn't leave any noticeable flapping in the wind.

The Gore Windstopper 150 fabric used throughout (with a lighter version of it used for the back panel for added temperature regulation) isn't quite waterproof, but suitably water resistant for showers and road spray, and the outer zip is partially covered to prevent ingress too. For me, that ticks the 'Rain or Shine' tag and covers any weather I'm likely to want to go out in, but if you're expecting genuinely heavy rain for prolonged periods, a dedicated fully-waterproof jacket is probably your best option.

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There's added bulk on the wind-facing parts of the arms and shoulders, while the black parts you can see under the arms and on the flanks are made of the same surface fabric, just without as much bulk, helping comfort and breathability. It's a very comfortable jacket to wear (even if you only wear it with a light baselayer) and is very practical too.

The pockets are deep and easy to reach and get into even with full-fingered gloves on, and they also feature neat laser-cut holes for drainage in the event that you are caught in a serious downpour. Those holes are cut into small reflective tabs, and there's more reflectivity in the shoulder seam taping and Castelli branding too, for front and side-approaching vehicles.

I'm also a fan of the zipped front pocket – very helpful for quick access to keys or a stashed gel when you're fighting the elements and don't want to stop.

All of this comes together in two very big figures: 522g in a large-sized garment, and that £275 price tag. The thing is, the weight adds to the sense of protection, while the price tag – remarkably – seems fairly justified given the performance and plethora of features on offer. Jackets like Sportful's Fiandre Extreme and any waterproof ones featuring Gore's ShakeDry fabric all price at around this level, but those are definitely wet-weather-specific without the thermal capacity of the Alpha RoS.

Its construction is practically flawless – a single loose strand in one of the shoulder joins between the inner liner and outer on our test jacket – and despite the slightly fussy interior, it looks super-smooth and sleek on the outside.

You can have it in the red on test, a sleek black or stylish blue, or a higher-visibility orange that really does look the part.

You'll naturally be wanting to take care of your big investment, and will no doubt need to use something like Nikwax's Tech Wash to keep its technical properties in tip top condition. You'll also want to reduce the stress on the internal seams joining the two parts together by zipping up at least the lining when washing. This also helps keep any untangling required to a minimum.

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Overall, the Alpha RoS is a winter jacket with the flexibility to be worn in anything from 5°C and lower, in dry conditions and anything short of a proper deluge, with all the features you could ask for. Yes, it's expensive, but if you look after it properly it's going to give many years of excellent service.

If you want an all-in-one winter jacket with a particular focus on cold weather, I'd say the Castelli Alpha RoS is right at the top of the tree.

Verdict

A brilliant deep-winter performer that takes the hassle out of dressing for the cold