The Castelli Alpha Jersey


This isn’t the Paris Roubaix. It’s your Sunday morning club run in cool and/or damp conditions. It’s your commute on your CX. It’s your late season charity ride which you hoped would be sunny when you signed up. It’s about finding something to keep you warm and dry.

Look, there are options. Buy a Gabba, ape the pros on the Paris Roubaix. Get a Gabba, get a bit wet, stay warm, ride fast. Buy a rain jacket, wear it over a long sleeve jersey, stay dry, and warm, and possibly a bit moist. Buy a gilet, protect your core, watch out for soggy arms, find somewhere to stash it if the sun come out.

There are options. A good cycling wardrobe should have plenty of options and in writing this review I’m not going to pretend that there are single pieces of kit that every cyclist MUST own. Buy what works, wear something for how it makes you feel. All options are open.

A little over a year ago someone started a thread on bike radar about the Castelli Alpha. That thread was about the jacket and jersey. They were new at the time, an unknown quantity. I didn’t start the thread, it’s up to 483 posts now and almost 30,000 views. But boy did I contribute to it. I guess I was one of the first people to buy the jersey, I felt I could contribute. In the end I guess I became a little bit evangelical about it. It wasn’t all about the Alpha, other jerseys and jackets are available. But it was the go to thread for people to discover what this new piece from Castelli was all about.

In my head there is a mainstream triumvirate of premium cycling manufacturers. They are Rapha, Assos and Castelli. There are others, some with as much history, some with as much technical know how, but arguably none with quite so much cachet or, if you like, brand visibility.

It’s hard to know where to start with Assos. They practically invented lycra cycling gear. They came up with the first lycra cycling shorts with a  chamois insert in 1976. This was space age. Over the years their frankly often baffling R&D and naming conventions have seen some truly advanced and wondrous products. Their bib shorts are, for my posterior, the best that there is. Admittedly, kitting yourself out in the top level winter jacket and bib tights from Assos will cost you the price of the average cyclescheme bike voucher. But who wouldn’t aspire to at least try their truly bonkers Bonka jacket? And if you want maximum comfort their top level bibshorts will let you gently house your gentleman’s sausage in its own bespoke “kuku penthouse with golden gate technology.” The Swiss, not famed for their humour. Assos produced truly brilliant kit at a price. Alan Sugar wears Assos. Their treatment of women in advertising material is debatable. You pay your money…………

In the time before Sky Rapha was a high end, lifestyle brand with a real focus on classicality. Their marketing was skewed to the aspirational and the gentleman gladiatorial cyclist. Sky’s arrival unlocked the “cheaper” end of the market, though this only really extended to “replica kit.” It was kit of high quality but hardly bargain basement. Whilst Rapha may have had plans to move towards the more pro orientated part of the market that move gained increased impetus with the need to kit out Team Sky. It forced Rapha to develop truly technical solutions to a range of riding conditions such as heat, cold and wet. Their Pro Team Range reflects this need and was produced in tandem with comprehensive real world team feedback. The materials they use are ultra modern and bespoke. There are waterproofs and windstoppers. Each of them works as well as its branded Gore Tex counterpart. I’ve no idea whether that bespoke material costs more than licensing a Gore Tex equivalent or whether its simply Rapha doing their own thing but it works. You pay your money………….

And then there is Castelli, a true Italian great; established over a hundred years ago; clothing supplier to the greats of the Grand Tours, Coppi, Anquetil, Merckx, Hinault. Such wondrous company, the stuff of legend. A brand with a scorpion as a logo.

For all that esteemed history Castelli is a bit different to the other two. Yes, you have the high end bonkers technical stuff, who can forget the radiation jacket? Look at today’s 7x Air Elemento. Out there R&D dealing with real world problems. Arguably, at the very top of the range their R&D matches Assos, even if their naming conventions do not. But there are cheaper, less overtly over engineered efforts at the lower end of the range. I won’t say bottom end. This isn’t Lidl. Indeed, Castelli’s lowest end sits fairly level with the very best from a brand such as DHB in terms of pricing. Aspirational and achievable perhaps? You can choose two.

In my DHB review I said that there’s nothing difficult about making a jacket. I stand by that. Once you come up with a basic method you can then over engineer it and make it a better one, it’s not difficult. An Assos Bonka jacket is just a soft-shell really, though the description of the fabrics printed on the inner zip tab pretends otherwise.

The same goes for long sleeve jerseys, just sew some good quality materials together. But there’s a trend now towards the jersey/jacket, a new hybrid form. It’s not new, Gore produce a jersey variant of their Xenon windstopper jacket. It’s a nice piece with windstopper material on the front and most of the arms. It’s truly comfortable and very lightweight. DHB produced the windslam jersey. A “lighter” soft-shell in form. It was very reasonably priced and superb bit of kit. A slightly heavier approach to the jersey/jacket but we are talking a few grammes overall. We have options for the days when a jersey isn’t enough but a winter jacket would be too much.

Castelli’s Alpha jersey is not a space age approach to the jersey or jacket, not really.  The majority of it is made from Windstopper 150. It’s a stretchy mid weight material that is utterly windproof, as you’d expect, but also provides a degree of water resistance. A degree. Yeah, we’ll come to that later. Some manufacturers err on the side of caution, and others…….


It’s all windstopper at the font and sleeves. Ignore the black half of the sleeves, that’s just contrast. It’s still all windstopper. Note that the zip has a storm cover from top to bottom, that’s an excellent touch in the absence of a waterproof zip. That big black band at the bottom is a giant elasticated section. Below is a photo from inside. As you can see it has a giant grippy castelli logo to make sure it stays in position. Nice touch. It works very well.


The rear is a roubaix type soft fabric, you can see how nice and fleecy it is n the picture below. It’s very warm and is coated with a water repellent coating in the same way as Castelli’s nano range. Remember that water will always run off a windstopper fabric to some extent. The addition of this repellent to the non windstopper rear helps an otherwise water retaining fabric do its job of keeping you warm and relatively dry.

So far, so good. It’s a lightweight soft-shell jersey jacket hybrid. But here’s the thing which makes it different. The inner insulation layer.


And that’s it. It’s like a tiny gilet really. Save that it has only a front. It’s made from a waffly heat trapping fabric. You zip it up. Then you zip the main zip up. A double insulation layer at the front. You should also be wearing your choice of base layer as well. It doesn’t look like much does it? It’s not even fleece lined. Just a waffle fabric. It doesn’t extend round your back. There’s no additional lining in the sleeves. A zipped up, sewn in extra bit of material. Oh.

30,000 views on bike radar. You don’t get that for a mis-step, well not unless you fudge some engine emissions. You don’t even get that for a discussion about the venerable Gabba. You only get that when someone has come up with something a bit special. Here’s the thing, it all works and it works brilliantly. The addition of that extra layer at the front keeps your core warm. You can feel the trapped heat and it radiates around you in truly cold conditions. But it regulates very well according to how cold it is. I suspect witchcraft is at play somewhere. You can wear this easily down to 5 degrees. You can wear it at 10 and be comfortable. You can even wear it at 15. You might like to ditch the long sleeve base layer and you might want to wear it with the inner zip open. It’s actually quite nice against the skin, you can wear it without a base layer if you really want to.

If you’re on a nice Autumn hilly circuit and you find yourself overheating then unzip your front. Leave your inner core exposed but the inner part zipped up to keep you temperate. Once you reach the peak zip up and descend. You can do all of these things. I’ll be honest, I don’t do it that often. It seems to work well for me in a range of conditions. It’s not as warm as a true soft-shell at zero but it was never really designed for that. Depending on how you hot or cold you run (I’d class myself in the middle here) you could actually use this as a winter jacket. Plenty on bike radar who claim to run “hot” use this through 3 seasons. There are summer days when it might be called on.

The fit is race. No, really really race. That elastic band waist is weird when you put it on. In fact, when I bought this first, I sent it back. It felt odd. You do need to size up. Indeed you might feel like sizing up on your already sized up Castelli. I stuck with my normal XL. It’s a form fit but once you’re on the bike it all makes sense. There are some excellent touches such as the raised and articulated fleece lined collar, one of the most comfortable things on my neck that I’ve ever worn. It’s effectively two pieces of material working together. The black piece is similar to what they make thermal beanie hats out of. Very soft and warm.


The rear has the standard three pockets and a tiny flap sealed one on the right hand pocket. You might be able to make that out on the photo. It’s to the right of the scorpion.


The rear pockets are fairly voluminous. They are very easy to access and all held together by a single piece of elastic trim. This proved fragile on a previous jersey I had so some care needs to be taken not to snag it, particularly with big winter gloves, but this one is holding up very well.

There is zero reflective material here. That’s a pretty big omission in my view. DHB managed this very well on the Aeron range by incorporating reflective material into the pocket retaining elastic strip. Cheap and easy and something Castelli need to think about. This is a global brand not just for nice bright October days around Lake Garda. It’s so easy to fix, so cheap to install. Adding something won’t spoil the looks. Castelli, sort it out.

And now, onto the rain……….oh the sweet, persistent, torrents of rain. I didn’t buy this jersey for the rain. I bought the Apex jacket for that. I never planned on wearing this when it was truly horrible, it’s just that some days work out that way. Two of them very recently were a true test of character and clothing.

Castelli made the Gabba for those conditions. I’ve owned one and I liked it. It worked as it was expected to, that is to say that it holds rain out, then gives up and works like a wet suit. Great for commuting (assuming you have a radiator to dry it on), great on the Paris-Roubaix, great on the Sunday morning club run. That’s IF you don’t stop for cake. If you do your left with a very soggy garment hanging on the back of your chair. That’s fine while you eat cake. Not fine when you leave again. I like the Gabba, but I accept its limitations. It is not the magical panacea that it’s sometimes made out to be.

The Alpha was never designed to be a Gabba. It’s for those cool days or those sparkling winter mornings when the temps start to rise. It was never designed for rain so it shouldn’t really work that well. And, yet, mysteriously, it does work. It works very well in fact and, dare I say it, for my purposes better than a Gabba. Not as good as a rain jacket, clearly, but just better.

The truth is there is no mystery here, it’s entirely to be expected. The Gabba is made from a windstopper material, Gore X-lite plus to be exact, and it’s water resistant to the extent that it’s a windstopper fabric. It takes ages for water to find its way through. The real ingress happens where panels are sewn together and rain eventually makes its way through shoulders and arms and, on the original Gabba, through the zip.

The Alpha is windstopper as well, Gore 150 as we’ve noted. It feels very different to the Gabba, more jacket like and less like a wetsuit. And, in my experience, it seems to work better as a water resistant jacket. It will eventually let go in exactly the same way as the Gabba because it has no internal taped seams. But it seems to hold out much better against rain for longer periods. That includes the rear which really shouldn’t work at all as it’s just DWR coated fabric. Yet that seems to work as well. Mechanically you miss a lot of rain because of forward momentum but the back of the Alpha jersey seems to shrug off rain admirably. My recent biblical rain commutes saw a jacket which started off dry, then the arms and front beaded the rain up because of the repellent coating and finally the outside was damp and clearly wet. But the water never really got in. And I remained toasty warm inside. That’s important because when something is wet through your momentum will act as a chilling mechanism. That doesn’t happen with the Alpha. Indeed, after one particular monsoon I dried the jacket with a towel and put it in the airing cupboard. After half an hour it was utterly dry outside and in. Not that there was much, if anything, on the inside in the first place.

Don’t get me wrong. I’m not recommending this as your rain jacket. I do think, if you want to ride in rain, something like the Apex is better. But if you’re out there and caught out the Alpha provides a huge degree of protection.

I’m a massive fan of the Alpha jersey. I consider it to be an indispensable addition to my wardrobe. It works best in red in my view but the “laurel” version is actually very nice in the flesh. The black version is the most slimming overall, of course, but it’s hard to recommend that as a true winter piece without someone addressing the lack of reflectives. I hope to deal with “being seen” in a piece shortly in that respect.

Price? Well, it’s not cheap. RRP is around £170. I didn’t pay that, indeed I paid a lot less than Wiggle’s current reduced price (£130). £170 is steep. It’s more expensive than most full soft-shell jackets. It’s clearly much more expensive than the DHB Aeron soft-shell which I favourably reviewed on here.

But that’s not really the point. The Alpha jersey has a niche and in that niche it leads the way. To get Alpha levels of performance you’re looking at a jersey and gilet combination and that will inevitably lead to some shortcomings (such as the sleeves lacking any form of wind proofing or water resistance). What the Alpha does so well is offer a single piece of clothing with great 3 (0r 4 given our climate) season versatility. It’s not yet perfect. They need to deal with the reflectives, but it’s otherwise one of the best pieces of clothing out there at the moment.

What about the Alpha jacket then? Should I buy that? Well, I’m a huge fan of that as well, but on that I would exercise some caution. Let’s talk about the difference first. It’s a full soft-shell so windstopper fabric replaces the rear roubaix of the jersey. The internal “gilet” is all round rather than only at the front. Finally, the sleeves are lined rather than being windstopper only. Net result? Warm at minus figures. Otherwise it’s pretty much the same overall. If you can get one at something other than RRP then it’s probably the warmest and most rain resistant winter jacket out there. Remember it’s much cheaper than the Bonka from Assos and can be found for less than the Rapha soft-shell. Amongst the triumvirate it’s a bargain. But here’s the thing. In true cold I want warmth, protection and breathability. You CAN have all three. I believe that the Aeron soft-shell gives me those and whilst I could make a case that the Alpha outperforms the Aeron it would be by tiny margins. Whether you feel that tiny margins justify a substantial difference in price is up to you.

But I’m unequivocal about the Alpha jersey. Get one now, while they’re reduced a bit. Or get one in April, when they’re reduced a lot. And stick it in the draw till it gets colder. Probably in July……………

Click here to buy

4 thoughts on “The Castelli Alpha Jersey

  1. Hi BTR, loving my Alpha Jersey, I now need to give it a wash. The instructions say cold 30, what sort of laundry soap would you use? I have normal persil and some nikwax liquid. Was hoping that it could be washed in a mixed wash with bib tights etc. My machine has 4 different 30° settings, one is a cold hand wash…. What’s your take on it?


    1. Generally I treat all my kit the same. 30 degrees machine wash. It’s about 15 minutes. I use a tiny bit of non bio. Does the trick. With bibs etc I wash everyone but jackets I don’t do as often. Once a week is enough Imo.


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