Arc’teryx Cerium SV Jacket
Size Tested: Large
Stated Weight (size M): 390 g / 13.8 oz
Blister’s Measured Weight (size Large): 430 g
- Moisture-resistant outer face fabric
- Compressible and packable
- Wind resistant
- DWR finish
- Insulated Mid-height collar
- Full front zip with chin guard
- Elastic cuffs
- Adjustable hem drawcord
- Includes stuff sack
- Internal chest pocket with zip
- Two hand pockets with zippers
Reviewer: 6’3″, 185 lbs
Test Duration: 25 days
Test Locations: Vail, Ouray, Rocky Mountain National Park, CO
Spend enough time in the outdoors in the chillier months and you’ll eventually find yourself in the market for some insulated outerwear or midlayers.
Winter climbers frequently find themselves in that most desperate struggle against the cold: the act of belaying.
While skiers routinely fight brutal conditions, they benefit from a more favorable balance of moving vs. standing still. Ditto for mountaineering. The more time I spend moving, the less insulation I need. In addition, that mobility can present opportunities to escape to a sunnier or more wind-sheltered area.
Not so with belaying. Confined to a very small footprint while waiting for your partner to finish the pitch is like being at the bottom of a well—a very, very cold well in the winter months. And if you aren’t prepared at the start of a belay, there simply isn’t a whole lot to be done other than pray that your partner will climb faster. Given that, belaying an ice pitch is where my day most hinges on what I brought to wear. (This is especially true when the lion’s share of quality ice in Colorado hovers around 10,000 ft.)
This is one of the major tricks of ice climbing: you’ve got to stay safe and focus on the climbing while you’re the one swinging the tools, but you’ve also got to manage your belay. I.e., you’ve got to survive a stint holding the rope, but also stay warm enough while doing so that you can then turn around and actually climb rather than immediately bail in search of a hot shower. (Remember: ice climbing is fun! You’re having fun doing this on your day off from your job!)
For the second half of the past ice season and the first few weeks of this new one, I brought the Arc’teryx Cerium SV to help with those unfavorable belay conditions. The Cerium SV is the warmer version of the Cerium LT jacket (size Large – with a hood = 300 grams), following the same logic of construction as the more versatile LT, or the even lighter / lower-profile Cerium SL (size Large – no hood = 200 grams).
The Cerium jackets are constructed with a combination of 850-fill down and two different grades of synthetic insulation (Coreloft 100 and Coreloft 140). Because synthetic fills like Coreloft are heavier but don’t suffer from the same hygroscopic Achilles heel as down, they offer more robust performance when damp, albeit at the price of a small weight penalty.
The Cerium jackets are built to try to have it both ways: Coreloft is used in the areas of the jacket where moisture will build up during use, while the goose down is spread throughout the remaining bulk of the jacket.
In practice, this means that there is Coreloft beneath the arms (where you’ll do most of your sweating), but small panels of the synthetic insulation are also thoughtfully added around the wrists; at the front of the hood where the zipper covers your mouth; and on top of the shoulders where pack straps might normally cause traditional down to bunch up.
The cut and size of the Cerium SV allow the jacket to conform well to the body without limiting movement or discouraging layering underneath. Granted, most winter base layers and mid layers are wool-or-nylon sausage casings, but the Cerium SV manages to fit easily over a cold weather layering system without an excess of material that can snag or become clumsy.
The Cerium SV shares this cut with the rest of the Cerium jacket series, is slightly slimmer than the Brooks Range Mojave, and is similar to the Feathered Friends or Patagonia down jackets I’ve worn in the past—at least as far as torso volume is concerned. And as a taller person, I’m always relieved when the sleeves reach my wrists. The Cerium, thankfully, checks this box.
Weight, Packability, Fill
Despite the use of synthetic insulation instead of down in strategic places, the weight and packability penalties of the Cerium SV are not egregious. In fact, at a measured weight of 430 grams (size Large), the Cerium SV is less than an ounce off from other all-down jackets such as the Feathered Friends Helios. It is less packable than both the Helios and the Brooks Range Mojave, but not tremendously so.
Ultimately, this strategic use of synthetic insulation is a clever work-around that offers a nice combination of the respective advantages offered by down and synthetic insulation. The end result is a high-performance belay jacket that should get you through anything you find yourself doing in the lower 48. Granted, high-altitude mountaineering demands a very specific class of jacket, but as far as continental objectives are concerned, the Cerium SV is the tactical nuclear weapon of cold weather insulation.
The Cerium SV, the warmest jacket in Arc’teryx’s Cerium line, is warmer than the Patagonia Down Sweater and Brooks Range Mojave that I’ve used in years past (though the Cerium SV is heavier and pricier than both). It’s a sizable step up, thermally, from the Cerium LT (the middle sibling of the three Cerium coats, and I find the SV to be warm enough that I only really wear it while idling at a belay stance, never while actively working.
Who’s It For?
This incredible warmth is at once the Cerium SV’s biggest selling point, but also one of the biggest considerations: Do you want / need this much jacket? Over the past year I’ve worn all three Cerium jackets in different conditions, and I ended up wearing the SV for the fewest days, by far.
The reality is that for cragging on cool-but-not-cold days, or for wearing around town, the Cerium LT or SL are more practical. The same is true for the Patagonia Down Sweater, Mountain Hardware Ghost Whisperer, and the like. The Brooks Range Mojave sits between the Cerium SV and Cerium LT, which is to say it’s on the warmer side of all-purpose jackets, and the Mojave gets more casual use than the Cerium SV for me.
However, on those days when it’s brutally cold, the Cerium SV brings more warmth in fewer layers, and easily trumps its thinner counterparts.
After going head-to-head with a collection of other down jackets, the Cerium SV has convincingly staked a claim as my go-to jacket for brutally cold conditions. For many casual users, or those looking for a jacket to do double duty in both active and around-town atmospheres, the Cerium SV might be too much. If that’s the case, then turn your attention to the Cerium LT or the Brooks Range Mojave: you’ll save weight, space, and money for a jacket that can be used most of the year.
For high-altitude endeavors, ice climbing, or any other situation where temperatures are low enough to pose a serious safety threat if they are not managed properly, the Cerium SV is pretty indispensable.