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  • Castelli Alpha ROS Jacket- Limited Edition - Men's
  • Castelli Alpha ROS Jacket- Limited Edition - Men's
  • Castelli Alpha ROS Jacket- Limited Edition - Men's
  • Castelli Alpha ROS Jacket- Limited Edition - Men's
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  • Castelli Alpha ROS Jacket- Limited Edition - Men's Back
  • Castelli Alpha ROS Jacket- Limited Edition - Men's Detail
  • Castelli Alpha ROS Jacket- Limited Edition - Men's Back
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CastelliAlpha ROS Jacket- Limited Edition - Men's
Sale $244.95 - $349.99

Item # CST00JS

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Item # CST00JS

Embrace the unpredictable.

Your cycling wardrobe likely consists of wet-weather gear and dry-weather gear, with little overlap. Until recently, those really were the only options, with wet-weather gear that would leave you feeling bogged down and steamy when you get pedaling, and dry gear that just couldn't hold up to more than a couple of raindrops. Castelli created the Gabba and Perfetto to help cover the bases for both, but the release of the Alpha ROS Jacket takes things to the next level. With limited edition colors, this model of the Alpha ROS Jacket captures the performance we expect from Castelli, along with an exceptionally stylish and elegant aesthetic.

The Alpha ROS Jacket is ready for rain or shine, with its two-layer construction that separates thermal insulation from wind and waterproof shell. The front offers a double-opening so you can ventilate without exposing yourself directly to the frosty chill. With two-layer construction, Castelli enables each layer to do their job to a higher degree, so Windstopper can keep its focus on sealing out water and wind, keeping the thermal layer dry so it can excel at regulating temperatures. The inner layer provides thermal warmth that wicks away perspiration and allows heat dissipation when needed, so your core temperature can be regulated and you're able to put down the power on long climbs without overheating.

Shielding you from the elements, Gore's Windstopper membrane is reinforced with YKK Vislon waterproof zippers and selective seam sealing. By being selective with seam-sealing, Castelli is able to maintain great dry-weather riding qualities on the Alpha ROS Jacket, without compromising water protection. Castelli won't make the claim that the jacket is 100% waterproof, but it does present the jacket with confidence to stand up to most cold and wet riding with resilience.

With a form-fitting cut that's much like a jersey, the jacket leaves little room for drafts or excessive fabric that flaps in the wind behind you. The cut is designed for in-saddle comfort, so you might notice the chest feels a bit tighter than normal across the chest when off the bike; however, on the bike the design is built to accommodate your arms, shoulders, and back when you are in the drops, eliminating extra fabric in that position. Since the design already features 2-layers you often won't need more than a baselayer to remove the chill, depending on the day's weather and your own preference. The jacket can span temperatures ranging from 23-to-50 degrees Fahrenheit, but—again—that depends on how hot your engine runs.

  • Pedal on through wind and rain in this cycling jacket
  • Limited edition colorway stands out in a crowd
  • Blocks wind and water with Windstopper 150 membrane
  • Insulating midlayer unzips separately for heat dumps on climbs
  • Race fit eliminates excess material and cold air drafts
  • Breathes and wicks away sweat on long climbs
  • Raw-cut hem and cuffs and comfort and improve fit
  • Castelli's revolutionary all-weather race kit continues to evolve
Tech SpecsSize
Tech Specs
[membrane/laminate] Windstopper 150, [face fabric] 100% polyester, [liner] 90% polyester, 10% elastane
Waterproof Rating
double-front opening
3 rear, 1 zippered side
Recommended Use
road cycling
Manufacturer Warranty
1 year


Men's Apparel




















































How to Measure:
For best results, take measurements over your underwear.
Measure under your arms, around the fullest part of your chest.
Measure around your natural waistline, keeping the tape a bit loose.
Measure around the fullest part of your body at the top of your legs.
Using pants that fit well, measure the crotch seam to the bottom of the leg.

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Nice Piece of Winter Kit

  • Familiarity: I've used it several times
  • Fit: Runs small
  • Size Bought: XL

Bought this on Joe D's advice (always great to work with). I've now used it at the coast from upper 30's with sprinkles and a 10+ MPH North wind, to the mountains in mid-40s with mist and drizzle, up to a clear mountain day that topped out in the mid-50s. These were 1.5 to 3 hour rides and the mountain rides included several Cat 2, 3 and 4 climbs.

As other riders have noted, the Alpha ROS is very versatile, with under layers key. At 5'10" and 170lbs I could wear a L, but the XL fits fine for winter workouts, allowing layering up with plenty of room, and layering down while still retaining a nice clean fit. The 3 back pockets are large and deep, and the front zippered cell phone pocket is perfect. If forced to list any down side, I would say the sleeves are just a tad long, the inner liner zipper is difficult (or impossible) to work with one hand while riding, and the Special Edition color is really cool but doesn't offer much in terms of high vis. Overall though these are minor issues.

As mentioned some of my test rides included significant climbs, with the corresponding cold (and fast) ride back down. Zipped up and popped on light gloves for the descent and the AROS kept me toasty.

I was worried I would overheat on a 3 hr mountain ride that got into the 50s but I didn't. I had a lightweight 3/4 zip under layer so I could left off some steam while climbing. It was still cool in the shade on north facing slopes, with a bit of snow left on side of the road, so the trade off between a little warm on the climbs and toasty in the shade and on descents was well worth it.

I've only had it in light rain so far, with no problems. And of course no below freezing temps yet. The AROS easily shed the rain I have been in, and I'm confident I can layer up for rides down to about 30. Much below that is below my lower overall temp tolerance anyway.

All in all the Alpha ROS is a great addition to my winter kit bag, especially at the Comp Cyclist Special Edition price. Thanks Joe for your expert advice!

Pretty solid jacket

  • Familiarity: I've put it through the wringer

Extremely nice looking jacket, very pro fit the collar on this thing is heaven. Let me begin with by saying I have a huge furnace and sweat an insane amount during intense workouts, so breathability is very important to me. I have worn this in 23 degrees with light weight base layer and it's been plenty warm, almost too warm. I've also worn this on 40 degree days, it's a little too warm at that temp. I do find that I need to unzip to let some heat out more frequently than I would like. Wind does not get through this jacket in the front or the sleeves I have worn this without base layers and have not gotten cold. Most of my rides have been road rides this fall / winter around 90 min and this jacket sheds water, wind, snow and anything you can toss at it. I only wish it was a little more breathable, but again it could be me and my temperature range because I can overheat very easily. I am 6' 180 lbs and wear an XL this fits racer tight with not a lot of movement in it, sometimes find it difficult to get stuff out of the pockets because it's tight on my shoulders.

Great Product!

  • Familiarity: I've used it several times
  • Fit: Runs small
  • Size Bought: XL

Kept me warm riding up Mauna Kea. When the temp dipped below 50 degrees I slipped this jacket on and stayed nice and warm at a low of 41 F. Wind resistant breathable material. Well made!

Gratz on climbing Mauna Kea, that's a beast! I'm going to climb Haleakala for the third time in January, so maybe I'll bring this jacket along! So far I've worn it mainly on cool days in Ohio. I do recommend to size up.

Impressive Product

  • Familiarity: I've used it once or twice and have initial impressions
  • Fit: Runs small

I've been curious about the Castelli products but hesitated due to price point. Recently, Competitive Cyclist ran a Castelli sale and I took the plunge.

I wanted a cold weather jacket able to handle lower temps. The Alpha Ros meets the challenge. I was so impressed with this product, I purchased the Alpha Ros for my wife. These do run a size smaller. Make sure you check the fit chart before purchase. Thank you Competitive Cyclist!

Very nice

  • Familiarity: I've used it once or twice and have initial impressions
  • Fit: Runs small

great jacket... runs very very small... i am 6 foot 204lbs... So def big for cyclist. But i actually had to order a xxxl... still fits form fitting without any extra material... and not tight. i say go up 2 sizes. if you are over 215 this is not a product for you

Runs way too small

  • Fit: Runs small
  • Size Bought: XXL

I ordered a XXL, which for cycling jackets usually fit me fine. I could barely get my arms in this jacket! Couldn't even zip it up. Sent it back.

Wind proof

  • Familiarity: I've used it several times
  • Fit: Runs small
  • Size Bought: large

Great on cold windy days....don't forget to get one size larger...
it'll still be snug.


  • Familiarity: I've put it through the wringer

I've been extremely pleased with the Alpha Ros Jacket. Winter training is sub 32 F degree weather is made simple knowing you'll keep warm and dry. I picked up the bright orange variant knowing it would contrast well in snowy conditions.

Sizing and fit remain consistent with Castelli's Euro fit and is not bulky at all. This a very versatile piece, the key is to vary your base layers based on the temperature you're riding in. I'll use a sleeveless summer base layer for warmer days or a heavy wool baselayer for the coldest of days.

Overall, this is my go to jacket during the cold winter months, and I think Castelli has done an excellent job on this piece.

Performs as promised

  • Familiarity: I've used it several times
  • Fit: Runs small
  • Size Bought: Large

I've been very pleased with this purchase, primarily because the product works as advertised. I have a few other cold weather jackets, but nothing that works as well as this one in providing good warmth, moisture management, wind and water resistance, and good fit with other parts of your kit.

Warmth: have ridden into the low 20's in Northern Virginia weather with a long-sleeve baselayer underneath and stayed plenty warm. The usual problem areas on most jackets are the arms, they start out warm but get cold as you start sweating underneath -- not so with the Alpha.

Moisture management - This is why your arms don't get cold. The multiple high performance materials around the arm let moisture escape.

Wind and Water Resistance - The dual-layer concept allows you to control the balance of airflow on your torso much better than traditional vent zips by ensuring that you still have some breathable insulation in the direct wind path. That pulls away excess heat and moisture over a wide range of needs -- fully zipped at very low temps, and much more open as you start working harder or the temperature climbs. Water resistance is similar to a Perfetto/Gabba jersey. It will hold off a mist throughout your ride, but don't expect it to keep you dry in a steady rain for more than about an hour and change.

Fit - The fit is typical for Castelli (i.e., runs small), I wear a medium in most race-fit jerseys (6'2"/168lbs), and a large fits me snug, but with room for baselayers underneath. Unlike some other jackets, the sleeves are snug enough to stay put underneath multiple types of winter gloves (fully insulated or thinner wind-proof style), yet don't feel constricting. The extra material on the back of the neck is a nice addition to a spot that frequently gets cold, but doesn't get in the way of a neck gaiter or balaclava.

In short, at a price much lower than a trainer, this jersey will let you ride in a much wider range of conditions than you thought you could.