Field Tested: Crux AK37 pack

The Crux AK37 is about as simple as a pack can get. There is one main compartment, albeit with the almost-obligatory hydration sleeve, and a fixed lid with a single, zippered pocket. There’s no key clip, no secondary mesh pocket, no other compartments. It’s basically a super-tough sack with shoulder straps and a waistbelt. This simplicity is at the core of Crux’s design philosophy of making tough, no-nonsense alpine packs.

In its 3rd generation, redesigned for Fall 2014, the AK-series of packs now uses a 40% Kevlar / 60% Cordura fabric, 8mm titanium stays and fully welded construction. There are no strippable components, but then the whole thing weighs only 1130 grams. That’s pretty light for a near-indestructible 37-litre pack!

Of particular note is the Kevlar/Cordura fabric which has so far proven to be extremely durable, taking all the abuse I’ve thrown at it without a single tear, despite numerous superficial scratches. I’ve so far dragged it through some canyons, up a number of rock routes, including some hauling in a couple chimneys, and of course countless ice and mixed routes in the Rockies. Readying the pack for this article’s photos (aka packing it), I noticed that one of the titanium ice-tool keeper tabs is actually ovalized from impact on one end — that’s a pretty good indicator of the wear-and-tear this pack’s been subjected to. The fabric is fully coated on the inside, as far as I can tell making it fully waterproof. However, due to the drawcord closure the pack itself cannot be considered a dry-bag.

TheAlpineStart_Crux_AK37_Pack_2The pack has picked up a lot of scratches – but I’ve yet to find a single hole, even after some rather abusive outings.

The top lid is fixed in place, which as long as you pack just the right amount of stuff, isn’t an issue. I do prefer floating lids, however, as it’s easier to strap down a rope, extra gear or just to contain an over-stuffed main compartment. The lid has a single pocket with a water-resistant zipper, and is roomy enough for a day’s snacks and various other essentials.

Inside, the somewhat-shape-holding foam panel is bolstered by two removable titanium stays. These come pre-shaped, but can also be easily bent to your preference. The stays are made of round titanium rods, which I didn’t think anything of until one particularly uncomfortable approach when what had been one of the most comfortable packs I use somehow turned into a kidney-gouging sack of pain. Turns out the round stays have a tendency to rotate inside their sleeves every once in a while, and end up either sideways or backwards, neither of which is comfortable. This isn’t something that happens with flat stays, so it’s just something to keep your eye on if you’re used to other packs.

Getting back to comfort, this is one of the best carrying packs I’ve ever used. Even with a full load and extra stuff strapped to the outside it carries well, but more remarkably, it sits well when climbing, too. The hipbelt folds in on itself and stays out of the way of a harness, though I have found that it’s comfortable even over a harness. The shoulder straps move with you while climbing, but again the fixed lid is a slight issue, getting in the way of my helmet when the pack is full.

TheAlpineStart_Crux_AK37_Pack_6The back panel, shoulder straps and hipbelt are pretty simple, but work well and are very comfortable even when massively overloaded.

Among the other features are hybrid metal-plastic buckles, which according to Carol McDermott, founder of Crux, are less prone to freezing as the point of contact is between two different materials, which react differently to the same temperatures. The waistbelt buckle also uses a hybrid metal-plastic design and is of the pass-through variety to ensure it won’t freeze, or bind, under even the most extreme conditions (see images for explanation!).

TheAlpineStart_Crux_AK37_Pack_11The hybrid metal-plastic buckles work like any other, and are much more resistant to freezing or breaking from impact.

TheAlpineStart_Crux_AK37_Pack_4The hipbelt buckle also uses metal and plastic. You pass the metal bit through the plastic bit and cinch it tight. Harder to explain with photos and words than I imagined, but very simple to operate.

Ice tool attachments continue the Keep It Simple Stupid vein. To attach tools, you just pass the titanium toggle through the tool’s head, and loop the elastic cord around the handle. It’s quick, simple, and works with every tool I’ve tried, from mountaineering axes to modern technical ice and mixed tools.

TheAlpineStart_Crux_AK37_Pack_10Lower tool attachment is exceedingly simple, pass the toggle through and you’re done.

TheAlpineStart_Crux_AK37_Pack_9Upper tool attachment is also quick and easy…

TheAlpineStart_Crux_AK37_Pack_8The simplistic nature of the tool holders accommodates any shape of ice axe / tool.

There are also compression straps, A-frame style ski carry loops, wand pockets and extra attachment points for a bungee cord as well as waistbelt gear loops. The haul/grab loop is massively oversized, and very easy to grab or clip to an anchor.

TheAlpineStart_Crux_AK37_Pack_5The massive grab strap is one of my favourite features: easy to grab, clip to an anchor and even great for organizing gear at a belay.

TheAlpineStart_Crux_AK37_Pack_7There are wand pockets and an A-frame ski carry straps on either side of the pack.

TheAlpineStart_Crux_AK37_Pack_3There are numerous loops for threading cord and creating a bungee system on the outside of the pack.

As you can probably gather from the materials (did you pay attention to all the Kevlar, Cordura and Titanium bits mentioned?!), this is not an inexpensive pack — $270 or so — though it isn’t that much more than directly comparable products. The AK37 is beautifully simple and focused in design, the payoff for which is a lightweight yet robust pack that will survive years of hard use.

Pros: durable, simple design, comfortable, light
Cons: fixed top lid, stays sometimes rotate
Overall: A tough, simple pack, equally suited to dragging through canyons and up mountains alike.

Crux packs are not a common sight in shops, but can be easily purchased through their website ( as well as several US-based online retailers,,

Note: Crux USA provided The Alpine Start with a pack for review purposes, but this in no way influences our opinion of the product.

5 thoughts on “Field Tested: Crux AK37 pack

  1. jc says:

    Hi Raf,

    Fantastic review. Thank you.

    One correction, there is no plastic frame sheet, just the closed cell foam panel.


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  3. Nomsta says:

    Did you feel that that the omission of a rope compressing strap on the top was an issue?

    • Raf says:

      In a perfect world, there’d be a rope strap. And a floating lid. But you can live without either. 🙂

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