Field tested: Arc’teryx Atom SL Vest

If you’ve read a few of my reviews, you’ll know my biggest pet peeve with climbing tops is a combination of short sleeves (especially with my ape index) and short hems, which inevitably causes it to untuck from my harness mid-route. For this reason, I’ve always championed pieces like the Patagonia R1 pullover (and long may it reign supreme). But I must say, I’m starting to come around to vests—after all, sleeves can’t be too short if they don’t exist! 

Being an ‘SL’ (Superlight) piece, I expected the Arc’teryx Atom SL vest to size quite snugly, but when the large arrived I was practically swimming in it. Thankfully Arc’teryx swapped it for a medium, which fit perfectly. Comparing it to the Nano-Air Light vest (Patagonia’s equivalent), they’re an almost identical cut, with the Atom SL feeling ever so slightly roomier in a medium and a centimetre longer at the hem. I slightly preferred the fit of the Atom SL, but raise your arms in either vest and the hems don’t so much as flinch beneath your harness—what is this sorcery?!

The Arc’teryx Atom SL vest sports the same materials and insulation as the Atom SL hoody, they essentially just cut off the arms. The outer shell is 20 dernier Tyono™ nylon fabric (like other Atom jackets), the inner lining is 20d Permair™ nylon fabric, and it’s filled with 40g/m² of Coreloft insulation (20g less than the Atom LT hoody/vest). This is also on par with the Nano-Air Light, which uses a slightly heavier 30d polyester fabric and 40g/m² of their own FullRange® insulation. The main difference with the Atom SL is the stretchy grid fleece side panels, which add some much-appreciated ventilation but more importantly, make it feel like you’re not even wearing a vest while climbing. I love the freedom of movement while wearing the Atom vest over a baselayer, and I find it noticeably more unnoticeable during very contortionist and athletic climbs compared to the Nano-air light, both bouldering and on a rope. The same goes for using it as a mid-layer, thanks to the cut and reduced bulk. This makes a big difference when the layers start to stack up in cold conditions—it’s no mystery why Colin Haley and Steve House like vests so much.

Of course, it wouldn’t be a review if I didn’t have any gripes…and I’ve got two. Firstly there’s no chest pocket. While Arc’teryx was thoughtful enough to include two harness-friendly zippered hand warmer pockets, they somehow thought this was more important than a zippered chest pocket (a strange choice considering most use vests as a mid-layer). They may argue this was to keep the weight low, as the Arc’teryx Atom SL vest weighs a mere 172g on my scale (43g less than the Patagonia vest), but I’d rather pay the weight tax and have somewhere to keep my phone/batteries/snacks warm. My second gripe comes in the form of a fleece-lined collar. While a fleece-lined collar should be a nicety, it somehow feels wrong on this vest, I think it’s unnecessary and more often than not I find myself annoyed by it. The fleece routinely collects chalk/dirt/bush debris and doesn’t do well with moisture. I would’ve preferred they either left the collar alone (like on the Patagonia vest) or used an Octaloft/Polartec Alpha Direct type fleece (I realise this is extremely pedantic). 

Final thoughts

For me packing this on a trip is a no-brainer; it’s so versatile that I can almost always find a place for it in my layering system. During the hotter months, I’ve mostly been using it as a standalone layer for early morning bouldering on granite. But once it gets cold again, it will no doubt be under a layer or two on some sandstone redpoints. It provides slightly less warmth than a Patagonia Nano-Air light vest, but feels better to climb in thanks to the stretchy grid-fleece side panels and has more room for layering (and costs a bit less). If Arc’teryx added a chest pocket and ditched the fleece-lined collar, I’d be one happy (perfectly temperature-regulated) chap. 

Key Details of the Arc’teryx Atom SL Vest

• Product: Arc’teryx Atom SL Vest
• RRP: $260.00 AUD
• Weight: 172g (measured)
• Insulation: 40g/m² Coreloft
• Materials:
  • Outer: 20D Tyono™ nylon
  • Liner: 20D Permair™ nylon
  • Side panels: Stretchy grid fleece
• Best For:
  • Climbers needing a lightweight, breathable layer
  • Use as a standalone in mild temps or a mid-layer in cold weather
  • Excellent for movement-intensive routes or bouldering
• Pros:
  • Super light and packable
  • Great freedom of movement
  • Harness-compatible fit
• Cons:
  • No chest pocket
  • Fleece-lined collar collects debris

Overall Rating: ★★★★☆ (4.3/5 Blue Offsets)