Exceptional protection, come rain or shine.
A winter classic, the Castelli Alpha ROS Jersey Limited Edition holds its spot in your cold weather cycling wardrobe with vigor. Solving the problem of whether a jacket or jersey is ideal, the Alpha ROS Jersey situates itself as a hybrid between the two, with lightly insulating warmth and weather resistance, but without reaching an overpowering build that doesn't function well when the temperatures are shy of freezing.
As we prepare for another season of cold-weather cycling, it behooves us to pause for a consideration of winter climbing. Climbing makes you hot, so your body produces sweat. But then you hit the top, and the fast descent through cold air cools everything off—including the sweat. Since this chain of events usually means finishing a ride in clammy frigidity, confronting one or a series of taxing climbs during a winter ride is a daunting prospect.
Castelli's Alpha design seeks to remedy this. Your need to climb may be due to the restrictions of local topography, the desire to interrupt the monotony of winter base miles, or your own inability to just take it easy on a training ride. Whatever the case, the most immediately obvious feature that sets the Alpha ROS Jersey apart from its competitors is also the one that addresses this, the ultimate problem of winter cycling: how to eliminate sweat on the climb without freezing.
The Alpha Jersey's thermal layer is detached from the Windstopper layer in the front, so—unlike with other winter jackets—when you unzip the shell to let in the wind, you're only exposing the thermal layer, not your bare chest or baselayer. Since the thermal layer is protective but permeable, it lets the cool in evenly, all over, not just in one frigid blast at your sternum. The thermal layer is also more breathable than the outer Windstopper fabric, which means that it evacuates moisture from your microclimate even as your body creates it on the climb. At the top, you're as dry as possible, so you can zip up and descend without worrying about cold sweat on the rest of the ride. And if the climb is too hot even for the thermal layer, you can unzip it, too, allowing for even more microclimate control.
Featuring the same construction as the standard 2018 Alpha ROS Jersey, you can count on the Limited Edition model to perform exceptionally in cool weather days, whether sunny or full or showers—after all, Castelli's ROS stands for rain or shine. The ROS line is designed to cut through wet and windy conditions better than your typical jersey and provide a bit more warmth than a rain shell on its own. Because not all of the seams are sealed, the jersey is perfect for misty and drizzly conditions, but may not stand up to serious downpours without leaving you damp underneath. With a similar design to the Alpha ROS Jacket, the Alpha ROS Jersey features Windstopper material, but is a little bit lighter weight, making it suitable for slightly warmer temperatures.
In 2017 the Alpha ROS jersey saw some improvements that were carried on to this 2018 limited edition model, including new fabrics and a minimization of seams that increase weather resistance on dreary days. The zipper was also elevated to a waterproof design, keeping you sealed in, and laser cut drain-holes on the rear pockets keeps water from sitting and penetrating into the jersey.
On the back you'll find Nano Flex Xtra Dry that offers incredible water protection while maintaining breathability, so you can keep all unwanted moisture out. You might be wondering what makes the limited edition model different; this model features the same construction as before, but in an eye catching red hue that stands out with its bold and rich color in a sea of black and fluorescent yellow.
- A weather-resistant jersey with a race cut
- GORE Widnstopper offers breathable water protection
- Race cut eliminates cold air pockets and excess fabric
- Expels heat with ease with 2-layer front design
- Laser-cut drains in rear pockets keep gear dry
- Reflective accents boost visibility in low lighting and dreary days
- Item #CST00JR
- Q & A
Perfect Cold Season Climbing Jersey
- Familiarity: I've put it through the wringer
- Fit: Runs small
I do not live in the bitter cold but in central Texas I do ride in thirty degree weather and we have some serious hills. This is officially a jersey but I treat it as a jacket. The Gore Windstopper lives up to its name, the sleeve cuffs are great to keep the wind out. I typically go to this jacket in the forties to the thirties though I have used it in the fifties with no issues. Typically I wear a Showers Pass short sleeve merino base, but if it is colder I use the same but in long sleeve.
The key to making this a great jacket/jersey is being willing to use it as it was made, i.e. to zip and unzip it as needed. On hills you can unzip the outer shell to dump heat. If you continue to warm up you can unzip the inner layer as well. Then zip back up on the downhill as needed. It works beautifully.
The material is really amazing. It is pretty waterproof but in a heavy downpour will eventually let some liquid pass. On dry days you perhaps feel a bit damp on the base layer but the jacket passes the moisture amazingly well: I had my phone in a plastic bag in the middle pocket and it was damp from the fabric releasing the moisture from perspiration.
In sum, this is one of the best pieces of winter gear I have as it works very well and works very well in a number of different conditions.
Way too Small
- Fit: Runs small
- Height: 5'11"
- Weight: 185lbs
Castelli is very high quality, however, way too small. I wear a 42 in a suitecoat, the XL was more like a medium. All of their clothing runs 3 sizes too small. I normally wear a large very comfortably, 5’11”, 185 lbs. XL was way too small. Castelli garments are very nice in quality, color and purpose for cycling. I really wanted it to fit.
- Fit: True to size
- Size Bought: Large
- Height: 5'9"
- Weight: 168lbs
I'm 5'9" 168 lbs and purchased a Large. Fits snug and great. I have not used it in wet weather yet, but great in the cool weather. Internal vest is nice feature. I have one other Castelli Jackets (lighter) and they are excellent quality, fit, finish and features. To me it's worth spending a little more for a few good pieces (but get it on sale!).
- Familiarity: I've used it several times
- Fit: True to size
- Size Bought: Large
- Height: 6'1"
- Weight: 165lbs
I'm not sure what to call this garment. It wears like a jersey but protects like a jacket. The double zippers is a little odd, but it is nice to open the front and still be protected. I've done about 10-12 rides in some varied conditions. I've worn this with no baselayer in the mid thirties on a very windy day and was quite comfortable. Hovering around 40 with passing showers it kept me dry, well at least my body, and warm. Started out at 30F and finished several hours later at 50F and the jersey was perfect. For me I'd say with a light baselayer on a dry day this would be good down to about 29. I'm 6'1" and 165 and the large fit me beautifully. Highly recommend!