Queen of the mountain.
Winter riding can have 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.
- Item #CST009B
- Q & A
- 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.