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Main page » Men » Jackets » Bike jackets » Castelli Alpha RoS 2 Jacket - Electric Lime/Dark Gray-Dark Gray
Castelli's ultimate jacket, bringing warmth, breathability and a high level of rain protection along with a soft, comfortable fit. With a fresh update in its third generation, this jacket leads the way in demonstrating how a winter jacket should perform.
PRODUCT FEATURES
- Rain or Shine engineering makes this our best jacket ever for dry conditions while also providing significant rain protection
- GORE-TEX INFINIUM™ WINDSTOPPER® 150 fabric for wind protection with high breathability and effective rain protection
- Reduced seaming with seam sealing on shoulders reduces chances for water to enter through stitching
- Double-layer Alpha construction separates insulating layer from wind/water barrier to let you better regulate ventilation
- Water-resistant YKK® Vislon® zipper slides easily for better regulation of airflow
- Raw-edge waist with silicone gripper lies flat and seals out wind
- Double-layer cuff integrates with glove to prevent cold wind or water from entering at wrist
- Stretch fabrics with advanced patterning make for excellent close-to-body fit that still accommodates a wide range of body types
- Back ventilation
- 3 rear pockets with reflective laser-cut drain holes
- Zippered secure side pocket for valuables
Cyclingnews.com says this jacket is "sets an all-new benchmark in what a winter cycling jacket can achieve" and it's exactly what we think the perfect winter jacket should be. We started with a list of things we didn't like about the current jackets and set out to solve them-and in the process made our best jacket ever.
The first issue to resolve related to moisture management. 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 we 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 we'll completely open the outer layer to allow moisture to escape, and when we start the descent we close the outer layer and are completely dry inside. It works so well that sometimes it feels like magic. New for this year is a softer, warmer 3D insulation-layer fabric that provides better warmth, moisture management and fit.
Next we focused on 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 we've created a stretch layer with a silicone bead that lies flat and completely seals out wind without bunching or riding up. New for this year is a brand-new double-layer wrist opening with an inner layer to go 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.
Of course, the ultimate jacket will also hold up well in wet conditions, so we used GORE-TEX INFINIUM™ WINDSTOPPER® fabric along with waterproof seam taping on critical seams around the shoulder. 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. We call it "essentially waterproof," using our 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 we do longish rides in real rain and stay completely dry.
All these features make it a favorite of the INEOS Grenadiers riders, and the most versatile performance jacket for cold-weather training we've ever created.
Find more products here
PRODUCT FEATURES
- Rain or Shine engineering makes this our best jacket ever for dry conditions while also providing significant rain protection
- GORE-TEX INFINIUM™ WINDSTOPPER® 150 fabric for wind protection with high breathability and effective rain protection
- Reduced seaming with seam sealing on shoulders reduces chances for water to enter through stitching
- Double-layer Alpha construction separates insulating layer from wind/water barrier to let you better regulate ventilation
- Water-resistant YKK® Vislon® zipper slides easily for better regulation of airflow
- Raw-edge waist with silicone gripper lies flat and seals out wind
- Double-layer cuff integrates with glove to prevent cold wind or water from entering at wrist
- Stretch fabrics with advanced patterning make for excellent close-to-body fit that still accommodates a wide range of body types
- Back ventilation
- 3 rear pockets with reflective laser-cut drain holes
- Zippered secure side pocket for valuables
Cyclingnews.com says this jacket is "sets an all-new benchmark in what a winter cycling jacket can achieve" and it's exactly what we think the perfect winter jacket should be. We started with a list of things we didn't like about the current jackets and set out to solve them-and in the process made our best jacket ever.
The first issue to resolve related to moisture management. 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 we 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 we'll completely open the outer layer to allow moisture to escape, and when we start the descent we close the outer layer and are completely dry inside. It works so well that sometimes it feels like magic. New for this year is a softer, warmer 3D insulation-layer fabric that provides better warmth, moisture management and fit.
Next we focused on 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 we've created a stretch layer with a silicone bead that lies flat and completely seals out wind without bunching or riding up. New for this year is a brand-new double-layer wrist opening with an inner layer to go 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.
Of course, the ultimate jacket will also hold up well in wet conditions, so we used GORE-TEX INFINIUM™ WINDSTOPPER® fabric along with waterproof seam taping on critical seams around the shoulder. 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. We call it "essentially waterproof," using our 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 we do longish rides in real rain and stay completely dry.
All these features make it a favorite of the INEOS Grenadiers riders, and the most versatile performance jacket for cold-weather training we've ever created.
Find more products here
Castelli Size Chart
The following sizing information is taken from the current official Castelli size chart. For the best fit, Castelli recommends measuring directly on the body or over underwear. If your measurements fall between two sizes, Castelli recommends choosing the larger size.
Men – Tops
| Size | Chest | Waist |
|---|---|---|
| XS | 88 cm | 76 cm |
| S | 92 cm | 80 cm |
| M | 96 cm | 84 cm |
| L | 100 cm | 88 cm |
| XL | 105 cm | 93 cm |
| 2XL | 110 cm | 98 cm |
| 3XL | 115 cm | 103 cm |
Men – Bottoms and Bib Shorts
| Size | Hips | Inside leg |
|---|---|---|
| XS | 90 cm | 81 cm |
| S | 94 cm | 82 cm |
| M | 98 cm | 83 cm |
| L | 102 cm | 84 cm |
| XL | 107 cm | 85 cm |
| 2XL | 112 cm | 86 cm |
| 3XL | 117 cm | 87 cm |
Men – Gloves
| Size | Hand circumference |
|---|---|
| XS | < 18.4 cm |
| S | 18.4–20.3 cm |
| M | 20.3–22.2 cm |
| L | 22.2–24.1 cm |
| XL | 24.1–26 cm |
| 2XL | > 26 cm |
Men – Socks
| Size | EU shoe size | US shoe size |
|---|---|---|
| S/M | 35–39 | 4–7 |
| L/XL | 40–43 | 8–10 |
| 2XL | 44–47 | 11–14 |
Men – Shoe Covers
| Size | EU shoe size | US shoe size |
|---|---|---|
| S | 36–39 | 4–7 |
| M | 40–42 | 8–9 |
| L | 43–44 | 10–11 |
| XL | 45–46 | 12–13 |
| 2XL | 46–48 | 13–14 |
Women – Tops
| Size | Chest | Waist |
|---|---|---|
| XS | 79 cm | 63 cm |
| S | 84 cm | 68 cm |
| M | 89 cm | 73 cm |
| L | 94 cm | 78 cm |
| XL | 99 cm | 83 cm |
Women – Bottoms and Bib Shorts
| Size | Hips | Inside leg |
|---|---|---|
| XS | 87 cm | 75 cm |
| S | 92 cm | 76 cm |
| M | 97 cm | 77 cm |
| L | 102 cm | 78 cm |
| XL | 107 cm | 79 cm |
Women – Sports Bras
| Size | Bust | Underbust |
|---|---|---|
| XS | 81–85 cm | 65–69 cm |
| S | 86–90 cm | 70–74 cm |
| M | 91–95 cm | 75–79 cm |
| L | 96–100 cm | 80–84 cm |
| XL | 101–105 cm | 85–89 cm |
Women – Gloves
| Size | Hand circumference |
|---|---|
| XS | < 16.6 cm |
| S | 16.6–18.4 cm |
| M | 18.4–20.2 cm |
| L | 20.2–22 cm |
| XL | > 22 cm |
Women – Socks
| Size | EU shoe size | US shoe size |
|---|---|---|
| S/M | 35–38 | 5–7 |
| L/XL | 39–41 | 8–11 |
Women – Shoe Covers
| Size | EU shoe size | US shoe size |
|---|---|---|
| S | 35–37 | 3–5 |
| M | 37–39 | 5–7 |
| L | 39–42 | 7–9 |
Kids
| Size | Body height | Hand circumference shown in Castelli kids chart |
|---|---|---|
| 6Y | 116 cm | – |
| 8Y | 128 cm | 14.2–16 cm |
| 10Y | 140 cm | 16–17.8 cm |
| 12Y | 152 cm | 17.8–19.6 cm |
| 14Y | 164 cm | – |
Kids note: The official Castelli kids chart does not show a hand-circumference value for 6Y or 14Y. These fields have therefore deliberately been left blank.
How to Measure
- Chest: measure horizontally under the arms around the fullest part of the chest.
- Waist: measure horizontally around the natural waistline, keeping the tape slightly loose.
- Hips: measure horizontally around the fullest part of the hips with feet together.
- Inside leg: measure a well-fitting pair of trousers from the crotch seam to the ankle.
- Hand circumference: measure around the hand using a tape measure or a piece of string and a ruler.
- Bra: measure bust at the fullest point and underbust directly below the bust.
Fit: Castelli specialises in performance cycling apparel and many garments have a close-to-body fit. The manufacturer's general rule is to choose the larger size when your measurements fall between two sizes. Product-specific fit guidance always takes priority.
Source: official Castelli Cycling Size Chart, current manufacturer website. Status 08/2026.