Skip to content Skip to navigation

ALPHA RoS 2 JACKET

The top rated winter jacket, bringing warmth, breathability and a high level of rain protection along with a soft, comfortable fit. This jacket leads the way in demonstrating how a winter jacket should perform.

1 2 3 4 5  4.9  (13 reviews)

|

4520502

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
  • 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

Technical Features

Insulation

Waterproofness

info
Waterproofness tooltip 

Windproofness

info
Windproofness tooltip 

Breathability

Lightness

  • Weight:586 g
  • Temperature:-5°C - 10°C / 23°F - 50°F
  • Fit:Tailored
    info
    Fit tooltip

What It Is

The top rated winter jacket, bringing warmth, breathability and a high level of rain protection along with a soft, comfortable fit. his jacket leads the way in demonstrating how a winter jacket should perform.
GORE-TEX Infinium™ WINDSTOPPER®

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.

RoS - Rain or Shine

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.

Rosso Corsa

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.

PRO RIDERS

Garment supplied to the Soudal Quick-Step Team riders.

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 our staff and most of our ambassadors, and the most versatile performance jacket for cold-weather training we've ever created.
Reviews

Here is what our customers think about it

4.9

1

2

3

4

5

13 reviews

Awesome piece of kit - does exactly what it says!

14/01/2024

First ride in the Alpha 2 RoS today and it did exactly what I’d researched and hoped it would do. Sufficiently warm for a 1C start (with a very thin thermal base layer - I’d say at the limit of comfortable for me), amazingly very breathable when attacking some pretty steep climbs, and warm and wind proof on the descents and long flats. Temp maxed at 5C and the Alpha 2 RoS felt ideal then (maybe slightly warm at very high intensity - to give an idea of its warmth). By comparison my feet were numb all day! Size XL was perfect fit. I’m 84-85 kg ant 178. Not much room if you want to layer up but as described, no real need to. Will be my go-to all winter!

David Featherstone

1

2

3

4

5

5

When it gets really cold, it is the jacket to have

08/11/2023

I needed a cycling wardrobe update after having my last Swiss made kit for what must be 15 years. I had never really been 100% happy even though the old kit was expensive when bought. I wanted a jacket for really cold weather and after being immensely impressed with my Perfetto purchase, I bought one of these Alpha RoS in the sales. I was not disappointed. When sub zero it is excellent. I use it up to 5/6 degrees with a Prosecco LS base layer with no problems over heating and it is good down to zero. Sub zero I pair it with a Flanders warm LS base layer and it is good down to -4/5 degrees. I haven't had it colder to see if it works in even colder weather, but I would be happy down to -10 degrees with it. I have read some criticism with the next being a little large. I figure it is so you can wear a neck warmer buff type Thermo head thingy, which I do. I like to ensure a layer around the neck and up to the cap so I use a Pro Thermal Head thingy as a neck warmer and where in a "tight neck" jacket, it may be constrictive, with the Alpha RoS Jacket, it is perfect. I cannot believe how good it is. I paid this price 15 years ago for my old Swiss jacket and the technology used in it is exceptional. I am so happy with my new Castelli kit. When I used to look out at the weather and it looked bad, I had some trepidation, now its like "bring it on". I just ride around with a smug look on my face knowing I am warm and comfortable.

Colin Sinclair

1

2

3

4

5

5

Simply the best winter jacket

15/04/2023

I've worn it with thermo base layer from -5°C till 5°C. Below -5°C another layer (long sleeve jersey).

Steve

1

2

3

4

5

5

Love this jacket

28/01/2023

I rode this morning 32F with a sleeveless base layer and sun sleeves, I was warm in fact a bit toasty. I had to unzip at the top after a hour, It breathes very well! Highly recommend this jacket.

Abhi R

1

2

3

4

5

5

Quality product

29/01/2023

Worn this jacket once so far on 28thJanuary 2023 in Northern England. The temperature was 5 degrees with light drizzle and wind, felt more like 2 degrees.
As soon as I put the jacket on it felt warm, I wore a thin base layer underneath and immediately felt the benefit of the built in vest which showed its use when climbing and zipping the outer to dump some heat. It kept me very warm and shed the light drizzle easily. Very high viz in the electric lime colour and I have no doubt this will be my go to deep winter road jacket, far warmer than my Perfetto RoS 2 jacket. The only thing I can find to moan about is that the sleeves are too long and there isn’t a built in pocket for my pump but I’m very impressed overall.
Highly recommended

Andy Brown

1

2

3

4

5

5

La giacca invernale perfetta

08/02/2023

E' una giacca perfetta, non si potrebbe esigere di più da una giacca da ciclismo per affrontare le fredde pedalate invernali. Anche con temperature sotto lo zero la indosso mettendo una termica a maniche lunghe sotto a parto per la mia pedalata.
Il tessuto gore-tex offre una traspirazione eccezionale che ti permette di rimanere sempre caldo e asciutto. Quando esce il sole o nelle salite più impegnative puoi sempre aprire la zip per prendere un pò d'aria e rimani comunque protetto dal gilet interno.
Super acquisto!

Alessandro

1

2

3

4

5

5

The Best Winter Jacket Ever

20/12/2022

I have used this jacket for two cold, windy and damp New England winters already. Really shines below 40 degrees. Used in weather as cold as 16 degrees with only a jersey and long sleeve base layer. Lots of pockets (including a front zipper pocket) unlike other jackets out there. Fits like other Castelli garments (2 sizes larger than normal stuff). I am 5' 10", 163 lbs and wear an XL in this jacket (maybe they have adjusted the sizing in the past few years)

PaulyG

1

2

3

4

5

5

Best Cycling Jacket I've Owned

22/12/2022

I can wear this jacket at sub-20⁰F with nothing more than an under armor tee underneath and still be warm.

Nicholas

1

2

3

4

5

5

Outstanding Jacket

23/12/2022

This jacket is extremely well made and performs as described. I've ridden with it mostly in the mid 30s F up to high 40s F and felt very comfortable. The large vent in the back works well.

I rode today in 22F to 25F weather and it did a great job. I was really amazed at how well my chest felt in strong headwinds. I’m not good in cold weather but this jacket works so well, I’m actually not worried about the cold anymore.

Buy this jacket. Thank me later. :)

David

1

2

3

4

5

5

Toasty at 19°F

26/12/2022

It was 19°F with gusty winds @ 25mph. Winter storm Elliott 2022. My base layer was a long sleeve merino wool shirt. I stayed nice and toasty on a 2 hour ride which was a mix of road and trail. This jacket exceeded my expectations for warmth and comfort. It has so much potential with proper layering. Completely cut the wind and cold. I was so impressed I came home and bought their “Estremo” gloves. I hope they perform as well as this jacket did. I would ABSOLUTELY recommend this jacket. Road, Gravel, MTB, whatever. My only complaint is that the little zipper tab on the left side broke off on my first ride. Zipper still works, just no tab. But this jacket is so warm I can’t even drop a star because of the zipper thing.

Michael Duncan

1

2

3

4

5

5

Essential

18/12/2022

Supremely comfortable and technically brilliant jacket. I’ve worn it in 4C damp weather with only a very thin short sleeve base and it works flawlessly. I was not too hot even at high intensity but I was just warm enough when leaving the house before being “warmed up.” I also own a Perfetto long sleeve but I prefer the Alpha ROS now as I can skip the thicker Flanders base I usually wear with the Perfetto in winter. The Alpha also fits better. The sleeves are a little bit looser but the chest is still tight enough to avoid flapping. Highly recommended. For the record I am 190cm and 87kg and the XL Alpha ROS fits me perfectly.

Mark

1

2

3

4

5

5

COLLETTO PIU' ALTO DA UN LATO

28/08/2023

Tolgo una stella solo perchè il colletto da un lato ha la zip più bassa e questo fa si che una volta chiusa la zip la differenza di altezza tra un lato e l'altro del colletto sia ben visibile e faccia difetto.
Stavo quasi per restituire la giacca al negozio online utilizzato per l'acquisto ma poi ho visto che in tutte le foto dei vari colori nel vostro sito la giacca presenta in tuttte le foto lo stesso identico difetto.
Non la restituisco quindi perchè ho capito che tutte le giacce hanno la stessa asimmetria in altezza del colletto ma rimango sorpreso da questo che è un difetto soprattutto estetico ma che non mi aspettavo da una giacca di questo marchio e a questo prezzo.
Non discuto il resto perchè è al TOP di una giacca da ciclismo studiata per temperature bassissime.

Stefano

1

2

3

4

5

4

Favolosa

04/01/2023

Favolosa

Luca

1

2

3

4

5

5

Awesome piece of kit - does exactly what it says!

14/01/2024

First ride in the Alpha 2 RoS today and it did exactly what I’d researched and hoped it would do. Sufficiently warm for a 1C start (with a very thin thermal base layer - I’d say at the limit of comfortable for me), amazingly very breathable when attacking some pretty steep climbs, and warm and wind proof on the descents and long flats. Temp maxed at 5C and the Alpha 2 RoS felt ideal then (maybe slightly warm at very high intensity - to give an idea of its warmth). By comparison my feet were numb all day! Size XL was perfect fit. I’m 84-85 kg ant 178. Not much room if you want to layer up but as described, no real need to. Will be my go-to all winter!

David Featherstone

1

2

3

4

5

5

When it gets really cold, it is the jacket to have

08/11/2023

I needed a cycling wardrobe update after having my last Swiss made kit for what must be 15 years. I had never really been 100% happy even though the old kit was expensive when bought. I wanted a jacket for really cold weather and after being immensely impressed with my Perfetto purchase, I bought one of these Alpha RoS in the sales. I was not disappointed. When sub zero it is excellent. I use it up to 5/6 degrees with a Prosecco LS base layer with no problems over heating and it is good down to zero. Sub zero I pair it with a Flanders warm LS base layer and it is good down to -4/5 degrees. I haven't had it colder to see if it works in even colder weather, but I would be happy down to -10 degrees with it. I have read some criticism with the next being a little large. I figure it is so you can wear a neck warmer buff type Thermo head thingy, which I do. I like to ensure a layer around the neck and up to the cap so I use a Pro Thermal Head thingy as a neck warmer and where in a "tight neck" jacket, it may be constrictive, with the Alpha RoS Jacket, it is perfect. I cannot believe how good it is. I paid this price 15 years ago for my old Swiss jacket and the technology used in it is exceptional. I am so happy with my new Castelli kit. When I used to look out at the weather and it looked bad, I had some trepidation, now its like "bring it on". I just ride around with a smug look on my face knowing I am warm and comfortable.

Colin Sinclair

1

2

3

4

5

5

Simply the best winter jacket

15/04/2023

I've worn it with thermo base layer from -5°C till 5°C. Below -5°C another layer (long sleeve jersey).

Steve

1

2

3

4

5

5

Love this jacket

28/01/2023

I rode this morning 32F with a sleeveless base layer and sun sleeves, I was warm in fact a bit toasty. I had to unzip at the top after a hour, It breathes very well! Highly recommend this jacket.

Abhi R

1

2

3

4

5

5

Quality product

29/01/2023

Worn this jacket once so far on 28thJanuary 2023 in Northern England. The temperature was 5 degrees with light drizzle and wind, felt more like 2 degrees.
As soon as I put the jacket on it felt warm, I wore a thin base layer underneath and immediately felt the benefit of the built in vest which showed its use when climbing and zipping the outer to dump some heat. It kept me very warm and shed the light drizzle easily. Very high viz in the electric lime colour and I have no doubt this will be my go to deep winter road jacket, far warmer than my Perfetto RoS 2 jacket. The only thing I can find to moan about is that the sleeves are too long and there isn’t a built in pocket for my pump but I’m very impressed overall.
Highly recommended

Andy Brown

1

2

3

4

5

5

La giacca invernale perfetta

08/02/2023

E' una giacca perfetta, non si potrebbe esigere di più da una giacca da ciclismo per affrontare le fredde pedalate invernali. Anche con temperature sotto lo zero la indosso mettendo una termica a maniche lunghe sotto a parto per la mia pedalata.
Il tessuto gore-tex offre una traspirazione eccezionale che ti permette di rimanere sempre caldo e asciutto. Quando esce il sole o nelle salite più impegnative puoi sempre aprire la zip per prendere un pò d'aria e rimani comunque protetto dal gilet interno.
Super acquisto!

Alessandro

1

2

3

4

5

5

The Best Winter Jacket Ever

20/12/2022

I have used this jacket for two cold, windy and damp New England winters already. Really shines below 40 degrees. Used in weather as cold as 16 degrees with only a jersey and long sleeve base layer. Lots of pockets (including a front zipper pocket) unlike other jackets out there. Fits like other Castelli garments (2 sizes larger than normal stuff). I am 5' 10", 163 lbs and wear an XL in this jacket (maybe they have adjusted the sizing in the past few years)

PaulyG

1

2

3

4

5

5

Best Cycling Jacket I've Owned

22/12/2022

I can wear this jacket at sub-20⁰F with nothing more than an under armor tee underneath and still be warm.

Nicholas

1

2

3

4

5

5

Outstanding Jacket

23/12/2022

This jacket is extremely well made and performs as described. I've ridden with it mostly in the mid 30s F up to high 40s F and felt very comfortable. The large vent in the back works well.

I rode today in 22F to 25F weather and it did a great job. I was really amazed at how well my chest felt in strong headwinds. I’m not good in cold weather but this jacket works so well, I’m actually not worried about the cold anymore.

Buy this jacket. Thank me later. :)

David

1

2

3

4

5

5

Toasty at 19°F

26/12/2022

It was 19°F with gusty winds @ 25mph. Winter storm Elliott 2022. My base layer was a long sleeve merino wool shirt. I stayed nice and toasty on a 2 hour ride which was a mix of road and trail. This jacket exceeded my expectations for warmth and comfort. It has so much potential with proper layering. Completely cut the wind and cold. I was so impressed I came home and bought their “Estremo” gloves. I hope they perform as well as this jacket did. I would ABSOLUTELY recommend this jacket. Road, Gravel, MTB, whatever. My only complaint is that the little zipper tab on the left side broke off on my first ride. Zipper still works, just no tab. But this jacket is so warm I can’t even drop a star because of the zipper thing.

Michael Duncan

1

2

3

4

5

5
close
WE'D LOVE TO HEAR YOU FEEDBACK
Thanks for submitting your review! Your feedback is now pending approval by our team.
By clicking on the "Submit review" button, I declare that I have read the privacy policy and I agree to the processing of my personal data.
Thanks for submitting your review! Your feedback is now pending approval by our team.
You can compare a maximum of 5 items at once. Please Remove at least one product before adding a new one.