Select Page

Gear Review: Osprey Stratos 50 and Sirrus 50 Backpacks

Osprey Stratos 50 in Death Valley National Park.

Osprey Stratos 50 in Death Valley National Park.

Osprey Stratos 50 and Sirrus 50
$190, 47L/2,868 c.i., 3 lbs. 9 oz. (men’s S/M)
Sizes: men’s Stratos S/M and M/L, women’s Sirrus XS/X and S/M

How much do you have to spend to get a “good” backpack? If only I had a buck for every time I’ve been asked that question. Of course, finding a pack you’re happy with is a very personalized choice (my “5 Tips For Buying the Right Backpack” can help you figure that out). Still, like virtually every category of gear, packs come in a range of prices that reflect both the pack’s size as well as its technology, features, materials, and quality of construction—so, yes, price does correlate pretty closely with quality. In search of a pack that delivers good performance without sticker shock, I took the Stratos 50, newly updated for 2017, on a three-day backpacking trip in the Panamint Range of California’s Death Valley National Park.

The Osprey Sirrus 50 in Surprise Canyon, Death Valley National Park.

The Osprey Sirrus 50 in Surprise Canyon, Death Valley National Park.

Known for the comfort and smart designs in their high-end backpacks, Osprey takes aim with the men’s Stratos 50 and women’s Sirrus 50 at weekend backpackers looking for good quality in an all-around pack that’s more affordable. While these two packs don’t match the comfort and weight-carrying capacity you’ll find in, say, Osprey’s men’s Atmos AG and women’s Aura AG series, the Stratos and Sirrus deliver good value in terms of comfort and features for weekend outings or trips of up to four or five days, if you pack lightly.

Osprey Stratos 50 harness.

Osprey Stratos 50 harness.

Redesigned for 2017 with adjustable torso lengths, to let you dial in a better fit, the signature feature is the AirSpeed suspension, a seamless, tensioned mesh panel integrated into the hipbelt and shoulder straps that allows air flow across your entire back, for a superior cooling effect on hot days of hiking.

Considering the fact that the AirSpeed suspension holds the pack’s weight off your back, I found it pretty stable, not tending to shift, even when scrambling up wet, slick limestone and short, third-class sections on an off-trail hike up Death Valley’s Surprise Canyon. The LightWire alloy peripheral wire internal frame with one aluminum stay, and the moderately padded hipbelt and shoulder straps, carry up to about 35 pounds comfortably. The curved hipbelt wraps smoothly over hipbones to distribute weight evenly.

Osprey Stratos 50.

Osprey Stratos 50.

Both of these top-loading packs have a wide enough opening and body for easy loading and seeing inside. Like Osprey’s pricier models, the Stratos and Sirrus have plentiful organization, with stretch-mesh side pockets, a large shove-it pocket on the front with two zippered, vertical pockets on it, plus zippered hipbelt pockets large enough for two or three bars each.

The packs include convenient features like a side zipper for quick access to the main compartment; an integrated rain cover; a zippered sleeping bag compartment on the bottom; a trekking poles attachment on a shoulder strap for freeing up your hands while on the move; dual side compression straps; and a removable lid. The main body of the pack is made of 210-denier nylon crosshatch fabric, while accents and the bottom are made with more-durable 420-denier nylon packcloth—the kind of adequately durable fabrics found in many moderately priced packs.

Osprey Stratos 50 side view.

Osprey Stratos 50 side view.

The Stratos 50 and Sirrus 50—also available in smaller versions, including daypack sizes, and panel-loading designs—won’t make any top-10 lists. You can find packs for backpacking that are lighter and more unique (and more expensive), as well as cheaper. But these packs strike a nice balance of affordable quality from a respected brand, and the addition of torso adjustability makes them even more appealing.

BUY IT NOW You can support my work on this blog by clicking any of these links to buy an Osprey men’s Stratos 50 at,,, or, or a women’s Sirrus 50 at,, or

See my “5 Tips For Buying the Right Backpack” and “Gear Review: The 10 Best Packs For Backpacking,” all of my reviews of backpacks and backpacking gear I like, and these stories at The Big Outside:

My Top 10 Favorite Backpacking Trips
10 Tricks For Making Hiking and Backpacking Easier
7 Pro Tips For Avoiding Blisters
The Simple Equation of Ultralight Backpacking: Less Weight = More Fun


This story took quite a while to write, so if you enjoyed it, please consider giving it a share using one of the buttons below. I’d really appreciate it.


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


Hi, I’m Michael Lanza, the creator of The Big Outside, recognized as a top outdoors blog by USA Today and others. I invite you to get email updates about new stories and gear giveaways by entering your email address in the box at the bottom of this post, and follow my adventures on Facebook and Twitter.


This blog and website is my full-time job and I rely on the support of readers. If you like what you see here, please help me continue producing The Big Outside by making a donation using the Support button at the top of the left sidebar or below. Thank you for your support.


The Big Outside is proud to partner with sponsors and Visit North Carolina, who support the stories you read at this blog. Find out more about them at my sponsors page. Click on the ad below for the best prices on great gear!



About The Author

Michael Lanza

A former field editor and primary gear reviewer for Backpacker Magazine, Michael Lanza created The Big Outside to share stories and images from his many backpacking, hiking, and other outdoor adventures, as well as expert tips and gear reviews to help readers plan and pull off their own great adventures.


Leave a reply

Your email address will not be published. Required fields are marked *

  1. Avatar

    One more question! Is the wrapping feeling the same as with the Atmos AG 50?

  2. Avatar

    Do production units have a side zipper for quick access to the main compartment too?

  3. Avatar

    Im an Osprey guy. Got a pretty large and unnecessary collection(according to my girlfriend)…but hey we all have our addictions. Mines the outdoors. I have last years version of the Stratos 50 and it’s one of my fav packs for all the reasons mentioned in this review. But what I love about it, and why I grab it whenever I fly is it’s shape. Even tho it’s 50L, it is not as tall as my Atmos 50 AG or even my Talon 44! It’s shorter and squatter shape enables me to bring it on flights as carry on without a worry. It’s my go to pack for when I fly.

    • Avatar

      Thank you for this info! I have the Atmos 50 and am thinking about going to the Stratos and it being a legit carry on is a great feature to have. Between that, it being cheaper and coming with a rain cover has likely pushed it over the edge for me.

    • Avatar

      Thnks fpr your answer Michael. It helps!

  4. Avatar

    Hi Jessy, companies sometimes make samples prior to production to share with gear reviewers, and they may make cosmetic changes on aspects like color when they go into production.

  5. Avatar

    How did you get a BLUE 2017 Stratos 50?? It only comes in red or black according to website.


Welcome to the Big Outside

photo of Michael Lanza

Hi, I’m Michael Lanza, creator of The Big Outside and former Northwest Editor at Backpacker magazine. Click my photo to learn more about me and my blog. Click here to sign up for my FREE email newsletter. Join The Big Outside now to get full access to all of my blog’s stories. And click here to learn how I can help you plan your next trip.

Pin It on Pinterest

Share This