
NOTE: Click here to read my review of the 2018 version of the Osprey Exos 58 and Osprey Eja 58 backpacks.
Ultralight Backpack
Osprey Exos 58
$220, 55L/3,356 c.i., 2 lbs. 8 oz. (small, fits torsos 16-19 ins.)
Sizes: unisex S-L (M 58L/3,539 c.i., fits torsos 18-21 ins., L 61L/3,722 c.i., fits torsos 21-23 ins.)
moosejaw.com
When Osprey introduced the Exos pack series in 2008, it immediately became a leader—and helped redefine how we think about backpacking. It showed us that a backpack weighing under three pounds can serve the needs of everyone from weekenders to longer-distance backpackers and thru-hikers, and it gave ultralighters an option to the minimalist rucksacks that fill that category (which are “minimalist” both in weight and comfort). As a fan of the original Exos packs, I took the new Exos 58 out on recent four-day, 86-mile backpacking trip in northern Yosemite National Park, and a seven-day, hut-to-hut trek on the Alta Via 2 through Italy’s Dolomites in July, and concluded that Osprey has taken something that was very good and made it lighter and better.

The secret sauce in the top-loading Exos—the reason it carries 25 to 30 pounds comfortably while itself tipping the scales at a pound or two less than many competitors—is the perimeter frame made of 6065 aluminum with a stabilizing cross strut. (Picture a somewhat squared-off figure eight.) The frame has only the slightest flex to it along both its vertical and horizontal axes—compared to, say, a plastic framesheet found in many packs that will flex much more—and the frame’s curved shape transfers much of the pack weight onto your hips, where you want it.
The trampoline-style back pad keeps the packbag off your back, making you feel much cooler. In Yosemite, I had a maximum of 25 pounds in the pack. And although we weren’t carrying backpacking gear on our Dolomites hut trek, I carried some of my kids’ clothing and personal gear (so they could hike with light daypacks on the rugged Alta Via 2); between that and my extra clothing and personal items for the two weeks we spent in Italy, I was hauling up to 25 pounds quite comfortably. The hipbelt and shoulder straps, made of highly breathable perforated foam, feel light and cool and disperse weight to prevent soreness. But the hipbelt lacks any rigid structure to it, so you don’t want to overload this pack. The suspension is fixed, not adjustable. The small size, for torsos 16 to 19 inches long, fit my 18-inch torso well, but may feel a little big on someone with a 16-inch torso, especially a small woman.

The design is utilitarian, with smart details. The removable lid pocket has beaucoup space for a pack in this category, plus a spacious, zippered valuables pocket on its bottom side. If you don’t need it, you can shave several ounces by leaving the lid at home, and the Exos has a built-in nylon flap that clips into place as a lid. As a photographer who frequently wants to get my hands free quickly, I like the convenience of the trekking poles attachment on the left shoulder strap—which was also handy when I scrambled slabs and crossed “aided” sections of the Alta Via 2, where you grab a fixed steel cable while traversing a narrow ledge. It also has smartphone-sized, stretch-mesh pockets on each shoulder strap, and standard features like tie-off points for attaching gear and attachments for carrying a single ice axe.
The stretchy front pocket can hold a couple of wet rain jackets, and two hipbelt pockets are big enough for a pair of energy bars or a GPS unit. You can reach into the deep, mesh side pockets from the top or the back side, and there’s a removable bottom strap for attaching a pad. Compression straps, buckles, and other plastic hardware are thin and small to minimize weight. The lightweight, 100-denier, high-tenacity nylon pack fabric is plenty durable, and the Exos 58 suffered no damage on the very rocky Alta Via 2. But treat this pack too roughly and you could tear the mesh front and side pockets.
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One caveat: As with any lightweight pack, especially one with a suspension that holds the pack off of your back, it becomes even more important that you load the pack smartly, keeping most of the weight close to the middle of your spine, and that you get a pack that fits you well. If you don’t do both, or if you put more weight in the Exos than it can handle, it will pull uncomfortably against the front of your shoulders when hiking.
If you generally carry less than 30 pounds backpacking and have modern gear that’s lightweight and low-bulk, or you’re a thru-hiker who wants a pack that offers a quantum leap in comfort and usability over standard ultralight models, you owe yourself a close look at the new Exos 58 or the smaller Exos 48 ($190, 48L/2,929 c.i., 2 lbs. 8 oz.). The Exos 38 ($160, 38L/2,319 c.i., 2 lbs. 5 oz.) is sized for use as a large daypack or for very ultralight backpacking.
BUY IT NOW You can support my work on this blog by clicking any of these links to buy an Osprey Exos 58 at moosejaw.com, ems.com, or rei.com.
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NOTE: I’ve been testing 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.
—Michael Lanza
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Hey Michael, got a question for ya. I’m looking to replace my daypack and was leaning toward this pack because it would also work for lightweight one and two night backpacking trips. I was just wondering what size to shoot for. When day hiking I will also be carrying gear for two kids and we also do some snowshoeing which requires more lays and get to carry along. I’m leaning toward the 58, what is your opinion? Thanks.
Hi Tanner, it’s definitely an ideal pack for overnight and weekend trips. I agree, you want the space of the 58L version, and it’s not that much bigger and heavier, anyway.
I went to my local REI today and he led out both the 48 & 58 Exos in large. I think both of them have the same size frame. They look exactly the same size! The extra 10 liters are very hard to see.
Hi Regan, the two different volumes of the Exos, the 48 and 58, are not hugely different, but I think you would notice it more when you load one versus the other. 10 liters is a significant enough difference that many backpack makers differentiate pack sizes in increments of 10 liters in the mid-size and larger packs. If your gear, clothing, and food fits in the Exos 48, go with it. But the 58 would give you more space if needed. Thanks for writing.