ALPHA RoS 2 LIGHT JACKET
Castelli's best jacket for mild conditions, with front wind protection, light insulation, maximum breathability, and water repellency to keep you dry in mist, light rain or spray from wet roads. This is a Castelli staff favorite thanks to the wide temperature range, fit and versatility.
£280.00
Color: MILITARY GREEN/FIERY RED-BLACK
|4520503-075
Product features
- GORE-TEX INFINIUM™ WINDSTOPPER® 150 fabric on front and sleeves for wind protection with high breathability and effective rain protection
- Nano Flex Xtra Dry on back for more ventilation allows heat and sweat to escape while shedding rain thanks to a nanotechnology water-repellent finish
- Alpha double-layer construction separates windproof layer from insulation layer, allowing better ventilation management
- Inner layer in ProSecco Strada for lightweight insulation with effective moisture management
- Double YKK® Vislon® front zippers
- Zippered secure side pocket for valuables
- 3 rear pockets with reflective laser-cut drain holes Raw-edge waist lies flat and moves with you
- GORE-TEX INFINIUM™ WINDSTOPPER® 150 fabric on front and sleeves for wind protection with high breathability and effective rain protection
- Nano Flex Xtra Dry on back for more ventilation allows heat and sweat to escape while shedding rain thanks to a nanotechnology water-repellent finish
- Alpha double-layer construction separates windproof layer from insulation layer, allowing better ventilation management
- Inner layer in ProSecco Strada for lightweight insulation with effective moisture management
- Double YKK® Vislon® front zippers
- Zippered secure side pocket for valuables
- 3 rear pockets with reflective laser-cut drain holes Raw-edge waist lies flat and moves with you
Technical Features
- Weight:490 g
- Temperature:7°C - 15°C / 45°F - 59°F
What It Is

We’ve engineered RoS as the no-compromise best clothing we know how to make for dry conditions, and then tried to make it as close to waterproof as possible without sacrificing breathability and ventilation.

Gore-Tex® garments provide total wind protection and maximum breathability. The windproof membrane keeps you from getting cold due to windchill, but the optimum breathability prevents overheating and moisture accumulation by allowing sweat to escape easily. Water repellency is ensured by the DWR treatment applied to the outer fabric.

Our Rosso Corsa label is only applied to the highest-level products we make. Every thread and fiber, every curve and contour is obsessed about. Rosso Corsa represents a categorical breakthrough in cycling innovation and the meticulous craftsmanship you expect from Castelli’s performance-enhancing apparel.

Exclusively engineered by Castelli. We take our thermal fleecy stretch Thermoflex fabric and coat it with millions of tiny nanofilaments to create the most water-repellent fabric finish ever. Drops of water stay as spherical balls on top of the fabric or bounce off the fabric without leaving a trace.
Here is what our customers think about it
2 reviews
Excellent cool weather jacket, with a slight let down
30/04/2023
Excellent cool weather jacket. Wore it on a 14c rainy morning and it kept me dry throughout the ride. I just had to unzip the top layer half way during the climbing efforts and any sweat buildup quickly evaporated, it really is very ventilated and comfortable. The only issue I had was with the side pocket zipper which snapped and broke off the first time I tried to use it. I wish Castelli put a better quality zipper on the side like the one in the front to make it a 5 start jacket. Also, sizing is perfect as per size chart - No need to upsize.
Tactical tool for Winter Riding
17/01/2023
I invested in the ALPHA RoS 2 LIGHT JACKET this year to provide me the ability to ride more in the cold, winter months. Let's say before purchasing this jacket, I was a bit more selective on what days and temperatures I would or could comfortably ride in. This jacket has not disappointed me! It provides me with comfortable wind and thermal protection with added light rain protection.
Look and Feel: Quality and feel is great. The material has a smooth, quality feel to it, yet not heavy or bulky. Check sizing carefully as I normally wear a U.S. large, but bought the XL, and fits perfectly.
My use so far: I'll take my last ride as an example: Thirty plus mile ride. Weather was mid to upper 40s (Fahrenheit), partly cloudy. I wore a thermal jersey under the jacket. I was completely comfortable. Kept me warm and shielded from frontal wind and cold. Back provided plenty of ventilation. I have had previous colder rides and was quite comfortable with a thermal jersey underneath. The ability to zip/unzip outer layer and the inner vest-like layer is awesome. It works well to help regulate my temp especially when I'm pushing it or expending more power.
I like the added secure zipper pocket on the left side. I use this for valuables, keys etc. The zipper position is a bit tough to open and close due to its location on your side. Harder to open with winter gloves... I take my glove off to open or access the pocket. But having a secure spot for my valuables has been great.
Bonus - Visibility is quite important to me especially in winter when rides can be during darker times. I love the bright green color and the reflective elements on the jacket.
I hope this helps others decide if this is the jacket for them!
Excellent cool weather jacket, with a slight let down
30/04/2023
Excellent cool weather jacket. Wore it on a 14c rainy morning and it kept me dry throughout the ride. I just had to unzip the top layer half way during the climbing efforts and any sweat buildup quickly evaporated, it really is very ventilated and comfortable. The only issue I had was with the side pocket zipper which snapped and broke off the first time I tried to use it. I wish Castelli put a better quality zipper on the side like the one in the front to make it a 5 start jacket. Also, sizing is perfect as per size chart - No need to upsize.
Tactical tool for Winter Riding
17/01/2023
I invested in the ALPHA RoS 2 LIGHT JACKET this year to provide me the ability to ride more in the cold, winter months. Let's say before purchasing this jacket, I was a bit more selective on what days and temperatures I would or could comfortably ride in. This jacket has not disappointed me! It provides me with comfortable wind and thermal protection with added light rain protection.
Look and Feel: Quality and feel is great. The material has a smooth, quality feel to it, yet not heavy or bulky. Check sizing carefully as I normally wear a U.S. large, but bought the XL, and fits perfectly.
My use so far: I'll take my last ride as an example: Thirty plus mile ride. Weather was mid to upper 40s (Fahrenheit), partly cloudy. I wore a thermal jersey under the jacket. I was completely comfortable. Kept me warm and shielded from frontal wind and cold. Back provided plenty of ventilation. I have had previous colder rides and was quite comfortable with a thermal jersey underneath. The ability to zip/unzip outer layer and the inner vest-like layer is awesome. It works well to help regulate my temp especially when I'm pushing it or expending more power.
I like the added secure zipper pocket on the left side. I use this for valuables, keys etc. The zipper position is a bit tough to open and close due to its location on your side. Harder to open with winter gloves... I take my glove off to open or access the pocket. But having a secure spot for my valuables has been great.
Bonus - Visibility is quite important to me especially in winter when rides can be during darker times. I love the bright green color and the reflective elements on the jacket.
I hope this helps others decide if this is the jacket for them!