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    Castelli - Alpha Jacket - Women's - Back
    Castelli - Alpha Jacket - Women's - Back
    Castelli - Alpha Jacket - Women's - Back
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  • Castelli - Alpha Jacket - Women's - null
  • Castelli - Alpha Jacket - Women's - Back
  • Castelli - Alpha Jacket - Women's - Back
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  • Castelli - Alpha Jacket - Women's - Zipper
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Castelli Alpha Jacket - Women's

Temporarily Out Of Stock

Don't get too bummed. This item is on the way and will be available for purchase as soon as it rolls into the warehouse.

Can't wait? Consider one of the other Women's Bike Jackets we have in stock.

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Tech Specs

Windstopper 150
Windproof Rating:
<1.0 cfm
3 rear, 1 zippered rear, 1 zippered front
yes, rear pocket
Claimed Weight:
335 g
Recommended Use:
Manufacturer Warranty:
1 year

Queen of the mountain.

Winter riding has its fair share of challenges, most of which can be addressed by the right combination of clothing and gear. However, we'd argue that trying to regulate body temperature while climbing is probably one of the most difficult parts of winter riding. After you sweat under your jacket during a long, exhausting ascent, the windy summit can quickly cool your body off, making the fast descent all chattering teeth and tense shoulders. Castelli took on the challenge of creating a jacket specifically made for winter climbing last year with the inaugural version of the Alpha. The brand received such positive feedback for the effort that the jacket is back, now available as the Alpha Jacket for women.

Castelli uses the typical sandwich of a Windstopper 150 membrane and thermal insulation in the Alpha, but the decision to keep the layers detached is what separates it from more traditional winter jackets and allows for the temperature control needed while climbing. As you heat up, unzipping the shell to let in the wind exposes the jacket's thermal layer, not your base layer or bare chest. The thermal layer insulates while remaining permeable, letting the air in evenly rather than in a shocking blast of cold, and it's able to wick moisture away continuously as you sweat to keep you as dry as possible when you reach the summit. At the top, you'll be able to zip back up as you take in the view without feeling clammy and cold for the rest of your ride.

As you begin that descent, you'll feel the benefits of the Gore's lightest Windstopper fabric, Windstopper 150. Though it's used as the shell of the Alpha, it's actually a windproof three-layer, four-way stretch knit fabric with a water-resistant DWR coating, so it doesn't feel overly bulky. It fits just as well on a base-mile ride as it does while you're riding at tempo or climbing out of the saddle, and the ventilating back panels mean that it doesn't trap heat.

Overall, expect the Alpha to have an aggressive race fit more reminiscent of a jersey than a jacket — it leaves just enough room for a base layer underneath, which we find is all you'll need outside of the deepest depths of winter riding. Castelli specifically constructs the jacket to accommodate your arms, chest, and shoulders while you're stretched out over the handlebars, and the only disadvantage to this is that it may feel tight across the chest when you're walking around off the bike—a small price to pay for impeccable fit in the saddle, in our opinion.

The Alpha features raw-edge construction at both the waist and wrists to provide more freedom of movement than elastic, which allows the wrists to integrate cleanly with gloves without bunching fabric. The waistband stays in place using a light silicone gripper and moves with you, maintaining coverage continuously as you ride, and the collar is cut so that it doesn't create a wind chute behind your neck while you're in the saddle. You'll have three jersey-style rear pockets for easy access to nutrition mid-ride, as well as a zippered rear pocket and zippered front pocket to keep your valuables safe.

  • A race-fit cycling jacket for deep winter
  • Windstopper 150 membrane shields against the elements
  • Maintains breathability and stretch for comfort
  • Outer and thermal layers unzip separately
  • Flat, raw cut hem and cuffs reduce bulk and lie flat
  • Three pockets supplemented by two zippered security pockets
  • Race fit is sleek but prohibits heavy layering
  • Recommended for temperatures around freezing


  • Familiarity: I've used it several times
  • Fit: True to size

Since I moved to Colorado this year I've been new to the cold weather riding and this jacket has been a life saver for me! The quality of the jacket is amazing. I bought the small size and I just love the fit. The arms have the perfect length, and it fits perfect on the toso without creating uncomfortable bumps when you lower your body on the bike.
I also love the inner jersey attached to the jacket because that way you can open the jacket while climbing to avoid getting extra hot but still have protection from the inner jersey. It has good pockets and great wind protection.
If you winter ride it is a must must!

Essential for all of us who winter ride

  • Familiarity: I've put it through the wringer
  • Fit: Runs small
  • Size Bought: Medium

First impression: Woah this jacket is seriously rockin'. Honestly the warmest cycling jacket I have ever owned and super quality design and fit, Castelli really thought of everything. I wear this jacket in a medium and I thought it would be a little bit tight since Castelli runs small but this jacket fits me like a glove. The arms are the perfect length and have a nice tight cut around my wrists to keep wind out. The windstopper fabric is absolutely the toastiest fabric. I've worn this jacket down into 20* with a winter base layer and it was super warm.I wouldn't wear it above 45* or 50* because you will be sweating for sure. I love how high the neck goes up, almost all the way to my chin they I zip it up, this really does a good job of keeping the wind out. At first I was skeptical about the inner zipper that kind of feels like a jersey attached to the inside of the jacket but I actually really like this feature! You can barely tell in the photo in the description but the inner zipper/ jersey like material makes it easy to unzip the jacket and still maintain a nice fit and not have the jacket flapping around. I will say that the inner zipper/ jersey part is pretty short compared to the rest of the jacket (goes barely below the top of my bibs) but once I'm bent over on the bike this is not an issue. Just looks a little funky in the coffee shops but its what you do on the bike that matters;) You can see the inner zipper/jersey (can't think of a better way to describe this feature...any suggestions??) in the super intense and not staged photo below. Keep in mind while it looks sunny and nice in the photo, it was 32*. However, I was unfazed by the cold because of this rad jacket and was able to maintain my silly facade and not be grumpy/freezing, so cheers to that!

Overall seriously love this jacket and I recommend it to all my lady friends out there who like to bear the bitter winter temps to play bikes.

**I wear a medium in Giordana jackets and medium in Castelli jackets--if you want a more loose fit in this jacket I would recommend sizing up, it is definitely really form fitting even in a medium for me***

Essential for all of us who winter ride

Odd Fit Outweighs Quality Construction

  • Familiarity: I returned this product before using it
  • Size Bought: Small and medium

The fit of this jacket is truly odd, in my experience.

Normally a size small fits me almost perfectly in Castelli tops, with a bit of room to spare for an extra layer. If anything, the waists are slightly loose, but the shoulders fit fine, even though mine are rather broad. For reference, I am 5'3", 127 lbs., 34" chest, 27" waist.

However, with the Alpha, the chest and shoulders were so narrow, and the material so inflexible that even the medium felt like a straight jacket in those areas. Conversely the waist was comically big in both the small and medium, puffing out like a balloon.

When a friend of similar height, but with narrow shoulders and a more blessed midsection, tried on the medium-sized jacket, it fit her wonderfully. Based on that, I would say it was styled mainly for that body type.

In terms of construction and materials, the Alpha is of high quality, as most Castelli products are. It is a beautiful jacket. Unfortunately those aspects are far outweighed by the perplexing fit.

True to product description

  • Familiarity: I've used it several times
  • Size Bought: small

This riding jacket delivers in the winter! I recently purchased it (winter 2016) to block wind and wick away moisture for road riding, and it has performed very well in as low as 24 F weather with base layer and thermal layer underneath (haven't had a chance to ride in lower temps yet). Also rode in 60 degree weather with only base layer underneath and it was comfortable - not too warm. It is lightweight, has great zipper side pocket for keys and ID and another zipper pocket further back which will easily hold a smartphone. It also has three open, deep pockets in the back. The length in the back keeps the wind out, and the high collar with a thermal neck piece in the back seals everything all around. It washes well and keeps its shape. As far as size, I typically wear an XS but purchased an S to have room for a couple layers underneath. Very pleased with this product.


  • Familiarity: I've used it once or twice and have initial impressions
  • Fit: True to size

I've only used this jacket once so far but it will be my winter go-to jacket. I rode in the low 50s, dropping to high 40s by the end of the day. I had just one base layer- Craft active long sleeve. The jacket was perfect- I unzipped as I climbed, then zipped back up for descents- never got too hot or cold. The offset zipper takes a bit of practice when trying to zip back up while riding. The jacket fit like a glove- no drafts or cold spots. I like the raw edge sleeves as it made getting gloves on much easier. I just pulled the glove edge over the sleeve edge. The jacket is very lightweight for its warmth.