Gear Review: Black Diamond Magnum 20 Daypack

Black Diamond Magnum 20
$90, 20L/1,220 c.i., 1 lb. 5 oz.
One unisex size

Strip away all that’s not absolutely necessary in gear and the result often is something you use over and over again. From a 23.5-mile, rim-to-rim dayhike across the Grand Canyon and a 13-hour, mostly off-trail dayhike of around 20 miles in Idaho’s Sawtooth Mountains, to shorter dayhikes in Zion National Park, as well as a seven-mile trail run-hike outside Ketchum, Idaho, and rock climbing at Idaho’s City of Rocks (carrying just water on the run and climbs), I kept slipping BD’s Magnum 20 onto my back—just for its simplicity and, of course, because it weighs barely more than half as much as a liter of water.

Black Diamond Magnum 20 front.
Black Diamond Magnum 20 front.

With no rigid structure to it, only a very flexible plastic framesheet and breathable, perforated foam back panel, and just a 20mm webbing belt (that’s removable to shave a few more grams), the Magnum trades off support for carrying more than about 10 to 12 pounds comfortably for a sleek and light design—it’s one of the lightest daypacks that still sports a basic but utilitarian feature set. It doesn’t compare with the best daypacks for comfort (see my picks for the seven best hiking daypacks). Still, I carried it across the Grand Canyon starting out with about 15 pounds inside (including water, food, clothing, and my DSLR), and the weight never felt onerous or imbalanced, or tugged unpleasantly against my shoulders.


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Black Diamond Magnum 20 back.
Black Diamond Magnum 20 back.

The fit of this unisex pack’s one size seems pushed to the upper end of its range on my 18-inch torso. The thin shoulder straps, made of breathable, perforated foam, don’t extend quite far enough to let the pack’s weight ride primarily on my hips when the pack is fully loaded—I loosened the straps as far as they would go. Taller hikers may find it too small, but it may fit many average-height to smaller men and women well.

Apropos of a daypack made for going light, a deep clamshell zipper that opens widely for quick access to the main compartment, which at 20 liters has plenty of capacity for all-day, three-season hikes.

The Magnum’s features include stretch pockets on each side that hold a liter bottle securely; a front stuff-it pocket large enough for a rain shell with room to spare, and a bungee on the outside of that pocket; zippered top and front accessories pockets; side compression straps; trekking poles/ice axe attachments; and a bike light clip as well as a bladder sleeve and port. With the exception of the side pockets—which could tear easily if you’re not reasonably careful—most of the pack is made with a ripstop nylon fabric that endures abuse as well as many heavier competitors.


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The Verdict

It’s not the pack to grab for maximum comfort when carrying more than 10 to 12 pounds, or if you prefer a fuller feature set. But weighing—and costing—less than most daypacks, Black Diamond’s Magnum 20 is a relatively inexpensive, no-frills pack for hikers and peak scramblers focused on minimizing weight on adventures from a few hours to a long day, and pulls double duty for bike commuting (although not highly water resistant), as a carry-on when flying (large enough for a laptop), or as a light, unobtrusive pack for multi-pitch rock climbs.

There’s also a Magnum 16 ($70, 16L/976 c.i., 1 lb. 1 oz.) that has adequate space for most dayhikers and will save you 20 bucks.

BUY IT NOW You can support my work on this blog by clicking any of these links to purchase a Black Diamond Magnum 20 at,, or, or a Magnum 16 at,, or


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See my “Gear Review: The 7 Best Hiking Daypacks” and all of my reviews of daypacks I like, plus my “5 Tips For Buying the Right Backpack” (which includes daypacks) and all of my reviews of hiking gear.

NOTE: I tested gear for Backpacker Magazine for 20 years. At The Big Outside, I review only what I consider the best outdoor gear and apparel. See categorized menus of all of my gear reviews at The Big Outside.

—Michael Lanza


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