The Atom SL is designed to handle subtle climate shifts. Balancing air permeability with wind resistance, the shell material allows airflow during active periods, but helps cut the chill during static moments. 40g/m² Coreloft™ Compact insulation is highly compressible, insulates if wet, and delivers its superior performance for very little weight. All the Atom SL’s fabrics are selected to manage moisture and provide comfort while on the move. Sleeves are lined with a comfortable mesh, and lightweight fleece side panels help provide thermal performance and ventilation. Articulated sleeves and gusseted underarms extend freedom of movement.
What the manufacturers say:
Warm weather is never a constant, even in summer. Fog rolls in, a sudden thunderstorm blocks the sun, and changes in elevation and levels of exposure can cause temperatures to suddenly shift. But summer conditions seldom require bulky insulation. The Atom SL Hoody is specifically created to hit the zone where insulation is required, but in a measured amount that suits milder conditions. Providing warmth comparable to a lightweight fleece for significantly fewer grams, the Atom SL is an efficient midlayer in cool conditions and a great standalone during rest breaks, early morning starts, and while enjoying the view from a freshly bagged peak.
- Weather resistant
- Compressible and packable
- Fleece stretch side panels for ventilation
- Mesh lined sleeves
- Arcteryx Nu. water repellent treatment
- Gusseted underarms
- Trim, slim, fit
- Adjustable low-profile uninsulated hood
- No Slip Zip front zipper
- Full front zip with chin guard and wind flap
- Shaped cuffs with stretch fleece
- Adjustable hem drawcord
- Drop back hem
- Two hand pockets with zippers
Arcteryx Atom SL Hoody on test:
Forget the brand name, forget the "social status" that sporting the Arcteryx logo gives, The Atom SL Hoody is a revelation. It looks innucuous at first sight and without that famous logo on the front you'd probably pass it by without a second glance on a sale rail, but the reality is it's precisely because of products like this that Arcteryx has its envious reputation. In many ways it defies logic in the way its minimalist design delivers more performance than many heavier-weight, more featured, competitors.
In terms of fit Arcteryx describe it as Trim and Slim, but don't get fooled by this, there's more room for additional layers than first appears. The drop hem, with a few extra centimetres at the back, is a real bonus in the UK climate and the clever zoning of the insulation makes it a product that's hard to define in terms of seasons or activities. It feels like a flimsy shower-proof shell but it performs across a greater range of temperatures than any jacket we've ever tested. Put simply it's a jacket that quietly goes about its job of keeping the weather out to the point that you forget you're wearing it. It's a mid layer that pretends to be an outer layer....or maybe it's a 3-season outer than pretends to be a mid layer.
Arcteryx Atom SL Hoody in front of the Eiger
Weighing in at 260g it's in the ultra-lightweight to lightweight class as a jacket, and as an insulation layer it's decidedly in the ultra-lightweight bracket. The minimalist weight is a product of the design which limits the insulation exclusively to the torso while the side panels, hood and arms remain uninsulated. You get 2 classic handwarmer pockets, large enough to accommodate a map, with good clearance of the waist-belt when carrying a pack. Of course you should remember that this is marketed as a spring/summer summer/autumn lightweight insulated hoody and not a full-on 4 season mountain jacket ………..but...…..if there's one criticism with the jacket it's that the marketers have been somewhat conservative. It hasn't been easy to test the insulation in the heatwave of a British summer but with the help of a flying visit to the Jungfrau area of Switzerland we managed to put it through a range of temperatures from -5C to 20C.
Coreloft isn't a well known insulation in a market dominated by the likes of Primaloft and Polartech and 40g doesn't sound like a lot of any type of insulation, but if the SL Hoody is anything to go by it's quality. Whether posing in front of the Eiger North Face of flying down a hillside at 50mph hanging prone under a zip line surrounded by cloud and getting hailed it performed perfectly. The stretch panels than continuously from the hem to the wrist, give all the flexibility you need while also helping regulate the internal temperature. Thankfully the stretch panels have also been Polygiene treated as they run directly under the armpits.
Stretch panels run up the sides of the jacket between the panels of Coreloft
The hem adjust by a single toggle inside the hem on the right hand side, with the ability to pull excess cord through to eliminate a loop hanging below the hem. Likewise the hood has a single toggle for hood adjustment, pulling on a cord that runs right around the lower part of the hood at the rear and up to the brim at the front. If there is a criticism with the design it's, surprisingly, in the hood design. As with any Arcteryx hood the one on the Atom SL Hoody holds in position perfectly with head movement but the combination of just a single adjuster and an unwired brim does mean the hood blows off quite easily if the wind picks up.
Defining where the SL Hoody shut sit in the market is difficult. It's definitely a windproof, but feels like a long sleeved shirt to wear, it throws off hail and snow at 3000m+ but you can happily trundle along a bike path in mid summer with the zip undone and not regret having it with you. It's warm enough as an outer layer down to below zero when you're active but you won't regret the weight in the rucksack if it gets too warm in the height of summer. If we had to classify it we'd say it's a 3 season lightly insulated, windproof, breathable lightweight shell that excels at transitions. At times we went from sunburn to snow, and everything in between, in the space of a couple of hours in the Alps and never once did we feel the need to swap it for something more dedicated to the conditions or supplement with an extra layer.