opefullyThe Durston Kakwa 40, unassuming at first glance, is a premium pack made with ultralight materials that offers surprising comfort and the functionality of packs that are much more expensive. I’ve taken mine from Canada, to the Alps and then to Hokkaido and cannot imagine there is a better pack at this weight and price point.
The Durston Kakwa 40 Review
- Sizes Available: 40 and 55L
- Weight: 800 grams for 40L
- Material: Ultra 200X
- Frame: Hollow Aluminum Upside down U
- Size Tested: Large
- Tester Height: 187cm
- Origin: China
What is a Kakwa?
The Great Divide Trail runs the length of the Canadian Rockies from Waterton Lakes to Kakwa Lake Provincial Park, roughly 1,140 km of bush-bashing, mosquito-dodging, lake-swimming wilderness. “Trail” is used loosely here; significant portions of the GDT are strictly off-trail. Dan Durston, the pack’s creator and the first person to yo-yo hike the GDT back in 2017, named the Kakwa after the route’s northern terminus. It’s a tough hike, and this pack is named, and designed, accordingly.
Design Philosophy of the Kakwa 40
With the pack’s name in mind it is easy to see why the pack was designed the way it was. The Durston Kakwa 40 was designed to be as light as possible but never at the expense of durability, load carrying ability and comfort.
Construction: Built Like a Tank
The Kakwa 40 comes in either Ultra 200X or Ultragrid. I tested the Ultra 200X, so that’s what this review covers.
Ultra 200X is a 3-layer laminated composite. The face fabric is 66% 200D UHMWPE, the same class of fiber as Dyneema, and 34% recycled polyester. Beneath that sits a diamond crosshatch of black UHMWPE yarns laid at 45 degrees, which is intended to keep the material from warping or stretching under load while boosting tear resistance. The interior is lined with a recycled polyester film that makes the fabric itself fully waterproof.
The Ultra 200X has a rough hand feel that has not softened after a full year of use. There’s minor stretch at a few points on the shoulder straps, but the pack has otherwise held its shape well, water resistance intact, and still looking clean apart from some ground-in dirt.
The seams, however, are not taped, so the pack as a whole is not waterproof. It handles a light drizzle without issue, but in sustained rain you’ll want a liner or waterproof stuff sacks for items you do not want to get wet. I’ve been caught in a few downpours and wished my down jacket had been bagged up. It wasn’t soaked, but it was wet enough that it wouldn’t have kept me as warm as it should.
Construction quality is overall very high. The seams are fully double-stitched with heavyweight thread, reportedly by the same factory that builds packs for Arc’teryx. After 1,000km of trail and a lot of international travel, I’ve had zero catastrophic failures. However, there is a small separation at the base of the left waist belt that seems to be going absolutely nowhere. I’m going to take this bag for another round of the Alps so I’ll let you know in 4 months how it holds up!
Shoulder Straps, Lightweight Frame and Padding
The S-shaped shoulder straps are covered in Ultra 200X with closed-cell foam padding. The yoke sits 8.5cm wide, keeping the straps from crossing over your traps, a small detail that makes a real difference on long days in the mountains especially when the weight of your gear picks up.
Load lifters at the top of each strap keep the pack pulled tight to your back and help the back pad stay flat to your back. Fair warning though: the straps are very long and will need to be rolled up, cut off, or tucked into front pockets. I should have trimmed mine ages ago but its a minor bug bear.
Tucked into the backpad and held in place by a very serious piece of velcro is the hollow aluminum U-frame and thin sheet of lightweight closed-cell foam. Both are removable, though I’m not sure why you would bother at 800g all-in for the Kakwa 40. There’s no trampoline or external channeling, so it does get warm against your back. By the end of most days the Ultra 200X is pretty well saturated, though I’ve never sweated all the way through even hiking eight hours in 30°C heat. Somehow it also doesn’t smell nearly as bad as you’d expect after this much use.
As the backpad of the Kakwa 40 is composed of the Ultra 200X, aluminum frame, and foam sheet care must be paid when packing the bag. If you randomly throw your gear in the pack you will likely end up with a bulge somewhere and need to repack.
Waist Belt
The Durston Kakwa 40 is rated to carry 45 pounds, which is a lot, and more than my 48-year-old knees are interested in finding out about. I have keep my carries to under twenty pounds and found that the frame transfers weight to the substantial hip belt effectively while keeping it from twisting under load.
Like the rest of the pack, the waist belt functions far better than its understated looks suggest. There’s no pre-curved shape or stiff foam but there is a very pliable 10cm tall closed-cell foam that lets the waist belt cup naturally around your hips. The dual-strap reverse pull snugs the waist belt incredibly well as it pulls equally from the top and bottom of the belt. It works better than it has any right to and can allow the pack to be carried as high or as low on your hips as needed.
On both sides of the waist belt are legitimately great hip belt pockets. They are both roomy enough for snacks, chapstick, a Zoleo or trail garbage. Amazingly, they are true single-hand pull. A small thing that is often not done right.
External Carry Options
The standout external feature is the kangaroo pocket on the back panel. It’s mesh with an elastic top sheathed in Ultra 200X, which lets wet gear breathe without going inside the pack. Rain in the forecast? Stuff your shell in there and you can grab it in seconds without digging through the bag. A Dyneema pocket would look cleaner, but the mesh hasn’t stretched, warped, or torn across more than 100 days of use, so it’s hard to argue with it. The mesh will breathe better than Dyneema as well allowing gear to dry quicker.
On the right of the pack body is a low-slung, angled stretch pocket that holds two smart bottles or Nalgenes easily and is reachable without taking the pack off. I keep my Katadyn BeFree here when I need it. On the left is a taller pocket with a flat closure that swallows any trekking poles and an umbrella with ease. Towards the backpacd side on the right is a small zipped pocket. I used this to stow tent pegs.
Each shoulder strap has a top-opening mesh pocket sized for bear spray, a phone, or sunglasses. I use mine for a Hydrapak bottle though neither the teardrop nor flat-bottomed 500ml Hydrapak soft flasks fit fully inside. You either have to loop a bungee over the cap to keep it from flopping around or under fill the bottles to 450ml and tuck the neck just below the pocket lip. Minor, but it’s the kind of thing you notice every single day. Apparently the new 500ml Pocket Flask Speed will fit. I have not gotten my hands on one to test this out.
There’s a large Y-strap over the top of the main body of the pack for lashing a rope, sleeping bag, tent, or foam pad to the outside of the pack. I don’t do many overnighters so I haven’t needed it. The strap is non-removable and very long so it does a lot of flapping around when empty. I have used a small piece of velcro to roll the excess up up but wish there was a non-permanent way to remove it.
The Y-strap., like all the other buckles on the Kakwa 40, closes with a Z-Type buckle. I find Z-buckles come undone a little too easy, especially when given a slight side load. I have replaced the waist buckle (because I stood on it and broke it). Hopefully, future iterations of the Kakwa have a standard buckle.
There is a hydration port on the right side of the pack but alas there is no hangar inside the bag. Thsi seems to be a strange oversight.
The Durston Kakwa 40 on the Trail
I’ve walked at least 1,000 km across the Haute Route, the Tour du Mont Rosa, a week in Hokkaido, and more days around BC than I can count. The Durston Kakwa 40 has become my favourite trekking pack and I say that as someone who swore they’d never leave a top-lid compartment behind.
The Kakwa 40 is comfortable, tough, and largely weather resistant at a weight most comparable packs can’t touch. Its understated look belies how much thought has gone into it.
I’d read plenty of glowing reviews from the Durston community, too many to dismiss as brand fanfare. So I reached out to Dan for a chance to review one, and I’m glad I did (and that he agreed!). It was my sole pack for summer 2025 and performed fantastically.
My gripes are a short list. The shoulder pockets don’t quite swallow a 500ml bottle, though that may be solved if the new Hydrapak bottles fit. The buckles are Z-type, and I’ve replaced the waist buckle — by necessity rather than preference. The Y-strap is non-removable, and there’s no hydration bladder hanger inside. All of these are easily managed, save for the bladder hanger, especially when weighed against the pack’s load-carrying ability, weather resistance, low weight, and comfort.
It’s rare that I’m not actively hunting for the next piece of gear to test. With the Kakwa 40, I’m happy to take it for another season of hiking in the Alps.
Looking for a Durston Kakwa 40, head on over to Durston to pick one up!
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BlackSheep was provided with a free sample of the Durston Kakwa 40 for this review. This in no way affected our editorial stance. This post also contains affiliate links; if you choose to purchase gear through these links, we may earn a small commission which supports our independent testing at no extra cost to you.
