All buttoned up the jacket can easily handle sub-freezing temperatures. In fact, I comfortably rode for a few hours on a 20-degree Fahrenheit day without getting a chill. In 32-degree weather I actually unzipped the outer jacket partially to catch some air through the vest. You can unzip the inner lining (but not remove it) for further cooling, but beyond about 40-45-degrees the jacket is actually too warm, but that’s about when I drop the gloves and move to some arm warmers anyway.
For true cold weather riding, the jacket is brilliant and feature-packed. The collar is tall and nicely articulated with a fleece backing that doesn’t irritate as you sweat. The sleeves are long and articulate with movement so you never get a dreaded glove gap. In the back the dropped tail adds some nice protection and warmth, especially when wet roads lead to spray. The Castelli-branded rubber gripped ensures it stays in place over bibs.
The body of the jacket is slim and Castelli sizing is very European – I had an XL on to test (6’1″ @ 185lbs), but it’s not restrictive.
The Gore Windstopper 150 fabric used throughout the exterior of the jacket isn’t waterproof, but does shed showers and road spray well, and the outer zipper is covered to prevent water seepage there as well. That covers any weather I’m willing to head out in at less than 40-degrees.
The bulk of the jacket is in the wind-facing components. The front facing parts of the arms, chest and shoulders are much thicker, while the under arms and flanks are made of thinner black material. That thinner material helps with comfort and allows breath-ability. All told, it’s an astoundingly comfortable jacket to wear while riding.
The jacket has a number of deep and easy to reach pockets that are accessible even with full-fingered gloves on. They even feature laser-cut holes for drainage in the even of a downpour. Those holes are cut into reflective strips, there is also reflective material in the shoulder seam taping and Castelli branding. The zippered front pocket is a nice addition, it’s great for storing a gel.
The jacket weighs in at 515-grams, which gives it a noticeable stoutness. The weight adds to the sense of protection and it’s construction is flawless. The red jacket I’ve been testing out looks smooth and sleek and it’s red! I’m so tired of cycling jackets only coming in black or high-viz yellow. If you dare buy another color, it’s also available in black, blue, and high-visibility orange.
Overall, the Alpha RoS is a dedicated winter jacket that will get you through just about anything you throw at it in sub 40-degree weather. It’s loaded with great tech features and thoughtful design and it has a price tag to match, but it clears some of the closet for one piece of kit and should offer years of excellent service. If you want a all-in-one winter jacket, the Castelli Alpha RoS is a brilliant performer.
Castelli Alpha RoS Jacket Features:
- Gore ® Windstopper ® 150 fabric is windproof highly breathable and offers great protection from rain and spray
- Seam sealing on the shoulders with a reduced seam main body and double stitching work to keep you dry in all but the worst conditions
- Dual layer Alpha construction separates insulation and protection to create better ventilation, moisture evaporation and breathability
- Articulated Collar for a better fit
- Part covered waterproof YKK ® Vislon zipper lays flat and slides easily
- Raw edge waist follows the body contours, lays flat and is low bulk
- Raw edge wrists create a perfect interface with Castelli gloves
- The stretch fabrics combined with the latest advanced patterning creates a close fit on a wide range of body types
- Back ventilation for greater comfort
- Castelli silicone text gripper at waist keeps the jacket from riding up
- Front zippered key pocket – with waterproof zip
- Three large open rear pockets with laser cut reflective drainage patterning
- Sizes Men’s S-3XL
- Weight 515 g (Size L, claimed)
- Castelli Comfort Range -5° to 10°C (23° to 50°F)