Castelli Alpha Doppio RoS Giacca Donna, nero

Cyclingnews.com says this jacket "sets an all-new benchmark in what a winter cycling jacket can achieve," and it's exactly what Castelli think the perfect winter jacket should be. With this next generation, the Alpha Doppio RoS Jacket, Castelli think they've made their best jacket better.

Even the best of the currently available fabrics provide a good level of breathability but can't keep up with the sweat generated during high-intensity riding.

So Castelli invented a double-layer construction that allows you to open an outer wind-protection layer while keeping the insulation layer closed and thereby allowing airflow inside the jacket to evacuate moisture while avoiding direct contact with the skin.

On a long climb you'll completely open the outer layer to allow moisture to escape, and when you start the descent you close the outer layer and are completely dry inside. It works so well that sometimes it feels like magic.

In this next generation, Castelli used a softer, warmer Polartec Alpha Direct insulating layer. Next, they made small changes to the openings: neck, waist, and, most of all, wrists.

The neck comes up high and is shaped to move with you, whether you're standing or in an aero position being a January hero and attacking your mates. For the waist, Castelli've created a stretch layer with a silicone bead that lies flat and completely seals out wind without bunching or riding up.

They've made some updates to the double-layer wrist opening, with an inner layer that goes under your glove that seals tight to your wrist, and an outer layer that goes over your glove so that any rain will roll down the outside of the glove and not end up inside.

This jacket will also hold up well in wet conditions, so Castelli used Gore-Tex Infinium Windstopper fabric along with waterproof seam taping on critical seams around the shoulders. Other seams are hidden out of direct water flow, and the water-repellent treatment on the fabric is sufficient to prevent most moisture from entering.

Castelli call it "essentially waterproof," using their own subjective judgment to find a balance between water protection, breathability and comfort. It doesn't mean that no drop will ever come in, but Castelli do longish rides in real rain and stay completely dry.

All these features make it a favorite of their staff and most of their ambassadors, and the most versatile performance jacket for cold-weather training Castelli've ever created.