This phrase kept running through my head while wearing the Arc’teryx AR 35: “It shouldn’t carry this well!” Lightweight and built of uber-tough liquid crystal polymer ripstop fabric, the AR 35 is a classic alpine pack with modern innovations perfect for mountaineers looking for a large winter day pack that can also serve as an overnight pack for summer mountaineering.
Arc’teryx Alpha AR 35 Features:
- Main compartment pocket essentials pocket
- Micro-webbing hydration hose loops
- N315r HT nylon 6,6 LCP fabric is a high tenacity nylon with a liquid crystal polymer ripstop grid
- Dual haul loops/carry handles permit hauling or clipping off at a snow anchor
- Fully seam-sealed for water resistance
- Adjustable, removable sternum strap
- 4 cm/ 1.6 in webbing hipbelt
- Thermoformed shoulder straps
- Removable framesheet and back panel for versatility and packability
- Two ice axe loops
- Six integrated front lash points
- Custom webbing daisy chains for lashing items, ice pick capture webbing accommodates a range of angles
- MSRP: $220

Old School Aesthetics, New School Tech
I love classic mountaineering packs with clean lines, simple features, and the ability to morph from a load hauler on the approach to a nimble on-route pack once the climbing begins. The Arc’teryx AR 35 hearkens back to Arc’teryx’s mountaineering packs from the late 90’s — clean, simple packs that carry well and have only the features you need. As a connoisseur of vintage packs, I appreciate the AR 35’s aesthetic sensibilities: the visible grid pattern of the rip-stop fabric, the bright colors that pop on summit shots, and the simple shock-cord to lash on crampons. In short, the AR 35 is old school cool, while simultaneously introducing a number of innovations to this category of packs.
“Single-use” products are no longer desirable in the current gear marketplace. Contemporary mountaineers, raised on high-tech fabrics and burly lightweight suspension systems, want packs that check multiple boxes. These days you seldom climbings trudging to basecamp with the 110-liter car-swallowing monster packs of yesteryear. Instead, mountaineers want a pack with strippable components that is both comfortable on the approach and disappears on-route. Typically, a pack with sacrifice either climbing efficacy for load-hauling capacity, or vice versa.
Through alchemy I still do not understand, Arc’teryx created a pack that accomplishes both goals.

If you have seen this pack in person and are now reading this review, you might find yourself skeptical of such a claim. After all, while the shoulder straps are made of dense but comfortable dual-density EVA foam, the hip belt is certainly not. Upon first glance, the AR 35 hip belt seems similar to the webbing of an ultra-light ski-mountaineering harness. Well, if it is not the hip belt that is doing the heavy lifting, perhaps the magic behind the AR 35’s comfortable carry is the result of some new space-age Arc’teryx suspension system… um, no. The suspension consists of a simple, removable, foam back panel, single aluminum stay, and thin HDPE frame sheet. In other words, the same kind of components you find in any number of alpine packs.

Yet, when these powers are combined, the AR 35 carries heavy loads incredibly well. Then, when the real climbing starts, the pack compresses well, becoming nearly unnoticeable. At no point while climbing in this pack did my arm movements feel inhibited, nor did the hip belt impede with the use of my harness. In short, the AR 35 does everything you dream of in an alpine pack.

Innovative Features
Arc’teryx has been making top of the line packs for quite some time, so it is probably no surprise to hear that the AR 35 carries well. What makes the AR 35 so interesting, however, is that is does all of this at a weight of only 41 oz. (2.5 lbs.). Arc’teryx achieves this weight through a series of innovative features. First, the majority of the pack is constructed of high tenacity nylon with a liquid crystal polymer ripstop grid. Arc’teryx calls this material N315r HT nylon 6,6 LCP. While the name might not roll off the tongue, nearly everything you encounter in the alpine — from scree to ice — will roll of this material.
Moreover, this lightweight fabric is incredibly strong, abrasion resistant, and very water repellent. While I do not recommend deliberately scraping your pack against granite outcroppings during a monsoon, I found the AR 35 immune to most abrasion and light precipitation. Gauging the abrasion resistance of a pack is difficult, so I speak only to my own experience with the AR 35, which included glissading in this pack with just about every spikey thing I owned strapped to the outside of the pack (crampons, mountaineering snowshoes, ice axe, and trekking poles), shimmying my way through sections of crusty spring ice, and using the pack as a seat during rest breaks. The AR 35 showed no signs of wear, despite my best efforts to brutalize it.

The best alpine packs have simple designs — a top-loading cylindrical pack body with minimal straps. Yet, anyone who has used a lightweight alpine pack knows of about pack sag… a literal pain in the butt. Lightweight materials are not rigid enough to keep their shape, which means heavy loads cause the pack to sag. The result is a pack weight that rides uncomfortably on the lower back and interferes with climbing movements. The AR 35 addresses this problem by adding a thin but stout layer of foam to the bottom of the pack. So, even with a heavy load, the AR 35 keeps its shape and allows the pack to ride comfortably on the hips and above the harness.
Next, the AR 35 incorporates a new lightweight and sturdy buckle system on both the lid and the main pack body. The lid of the pack, which is roomy enough for snacks, headlamps, maps, and even a windbreaker, uses two metal hooks to attach to the main pack body via a micro daisy chain. Users can easily move the hooks from one attachment point to another, lowering or raising the lid as necessary. At first this system seemed cumbersome (and a bit difficult to use with gloves); however, after a few days, I found myself enjoying the range of lid adjustment possible with this pack. Regardless of how full I stuffed the AR 35, I could make adjustments to the lid in order keep my kit covered and compressed.

Arc’teryx employed similar techniques with the other straps on the pack. Forgoing traditional buckles, the AR 35 uses small plastic toggles to capture 1 mm loops attached to the lid. The plastic toggles snap into place only when the straps are cinched down. At first, I was concerned that these small plastic hooks would not hold tension or simply break when cinching down the pack straps. I was wrong. Not only did they hold the lid in place, but they also kept constant tension, allowing you to effectively compress the pack.
These same straps and toggles are also for side compression. These “buckles” made opening the pack a cinch: simply flip up on the plastic toggle and the tension is released and the pack snaps open. The same can be said for the rope carry strap on the top of the pack. The rope is held secure on the approach and easy to remove when necessary.
Arc’teryx employs a similar design on the ice tool attachment points. Simple bungee toggles and a pick pocket hold the head of ice tools in place, while a hook and loop strap secures the handle to the pack. More and more packs employ clever tool attachment systems designed to be “intuitive,” but often end up being precarious, complicated, and unable to hold a modern range of tools. Arc’teryx bucks this trend. They created a tool attachment system that is minimal, stable, and easy to use with gloves.

Best Application
Arc’teryx markets the AR 35 as a do-it all alpine day-pack. While I agree with this description, I think the AR 35 is much more than a day pack. The pack feels larger than its advertised 35 liters, particularly when the spin drift collar is extended. And, given how well the suspension carries weight, I see this becoming my go-to pack for overnight alpine ascents in the summer. I wouldn’t recommend this as an overnight pack for those new to mountaineering; however, if your alpine kit is dialed in, you will find yourself reaching for the AR 35 for most alpine endeavors.
The Good
- Comfortably carries heavy loads on the approach
- Compresses down to a slim, back-hugging on-route pack when the climbing begins
- Innovative fabrics are weather and abrasion resistant
- Ice tool attachments are simple and stable
- Internal pocket is great for maps, headlamps, and other essentials
The Bad
- No exterior pockets
- Toggle “buckles” are awkward to use at first
- Lacks dedicated helmet carry
The Bottom Line: Arc’teryx Alpha AR 35
Finally, Arc’teryx earned a reputation for offering top flight products at top flight prices. However, the AR 35 marks a new approach for Arc’teryx. At $219.00 (MSRP), the AR 35 is competitively priced for an alpine pack of this size. However, with its unique feature set, innovative fabrics, and impressive suspension, the AR 35 sets itself apart from the crowd as a multi-use pack capable of replacing a number of packs in a climber’s alpine quiver.
Buy Now: Available at REI