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Osprey Stratos 34 Backpack REVIEW

New for 2006, the Stratos 34 daypack provides all the features, fit, and comfort you can ask for from a general use daypack. It’s also bomb-proof, and heavy by our standards.


by Will Rietveld | 2006-03-21 03:00:00-07

Osprey Stratos 34 Backpack REVIEW


With their 2006 introductions, Osprey will have more pack models than brands of cereal in your grocery store. The new Stratos line alone has five models. I tested the Stratos 34 general use daypack/overnight backpack - the largest of the Stratos line, and found a lot of nice features. The Stratos 34 is very similar to the popular Osprey Atmos 35, which was introduced in 2004. In this review I take a hard look at the Stratos and compare it to the Atmos 35. My pick of the two my surprise you.

Photo: The incredible balanced rock in the photo is for real, and can be found in the Red Canyon Recreation Area outside of Bryce Canyon National Park in Utah.

What’s Good

  • Panel loading
  • Excellent fit
  • Four outside pockets plus hipbelt pockets provide lots of convenient storage
  • Internal hydration sleeve plus additional water storage in backpanel cavity
  • Well ventilated backpanel
  • Straightjacket compression system
  • Very comfortable suspension system

What’s Not So Good

  • No hydration tube ports on main compartment
  • No hydration bladder hanger in mesh backpanel cavity
  • Mesh hipbelt pockets allow contents to get wet
  • At 2 lb 13.8 oz., the Stratos 34 is not lightweight





2006 Stratos 34


Internal frame, panel loading


Size Medium tested, 2100 ci (34 L)


2 lb 13.8 oz (1.3 kg) measured weight; manufacturer’s specification 2 lb 10 oz (1.2 kg)


210d high tenacity nylon, 210 x 420d ripstop nylon, two-way stretch-woven nylon with Lycra


AirCore tensioned mesh backpanel, contoured spacer mesh shoulder harness and hipbelt, two side compression straps, two front compression straps, large front panel access with double slider zipper, two side stretch-woven pockets, stretch-woven front pocket, two zippered mesh hipbelt pockets, upper frontpanel pocket with water resistant zipper, internal hydration sleeve with two side ports, zippered access backpanel hydration storage, load lifters, sternum strap with whistle, haul loop, dual ice axe loops, ski loops on lower sidepanels

  Volume To Weight Ratio

45.9 ci/oz size M (based on 2100 ci and a measured weight of 45.8 oz)

  Comfortable Load Carrying Capacity

20 lb (9.1 kg) estimated comfortable load carrying capacity for an average person carrying the pack all day

  Carry Load to Pack Weight Ratio

7.0 (based on 20 lb and a measured weight of 2.86 lb)




Building on the success of their lightweight Atmos pack line, with its innovative AirSpeed frame and mesh backpanel, Osprey is launching its Stratos line of general use daypacks with AirCore frame and mesh backpanel. The Stratos 34 is the largest of the Stratos line. It is a panel loader similar in size and features to the popular Atmos 35 (I will address the similarities and differences later in this review).

Osprey Stratos 34 Backpack REVIEW - 1
Front and side views of the Stratos 34. Osprey’s StraightJacket compression system utilizes the two straps on the front of the pack (left photo) to connect to the two open buckles on the side of the pack (right photo) to reduce pack volume for smaller loads.

The AirCore frame and tensioned backpanel borrow from the AirSpeed design found on the Atmos packs. It consists of two fiberglass struts that anchor into top and bottom Delrin Acetal (high-strength plastic) wings. The assembly fits tightly into a mesh pocket and anchors to a center stabilization disk attached to the main packbag. The result is a concave frame and tensioned mesh backpanel with a cavity behind it.

The AirCore design with its tensioned mesh backpanel is form-fitting and allows full air circulation. It molded to my back like a water bed. While other packs use spacer mesh or other porous fabrics to increase ventilation between the pack and your back, the tensioned mesh backpanel virtually eliminates the wet-shirt-behind-the-backpack issue. Needless to say, this design is a winner, especially in desert environments.

The Stratos 34 suspension system consists of sewn-in spacer mesh contoured shoulder straps and hipbelt. The hipbelt is fairly thin (about 1/4-inch) and soft, but wide to distribute weight. The front buckle uses Osprey ErgoPull straps, which employ a pulley design to apply pressure evenly.

Osprey Stratos 34 Backpack REVIEW - 2
The Stratos 34’s frame and suspension (top left) is full-featured, capable and comfortable. Its AirCore frame and backpanel (bottom left) consists of two concave composite struts creating a cavity that is covered with mesh. There is a zippered access at the top of the backpanel (bottom right) that allows a water bladder (or other gear) to be inserted in the cavity. My sample pack did not have a hanger for a water bladder, so the bladder slumped in the bottom of the cavity as it was depleted (top right).

The mesh backpanel has a zippered access and hydration tube port at the top, so the cavity can be used to hold a water reservoir or a Platypus flask. My sample pack did not have a clip at the top to suspend a reservoir. Inside the main compartment there is a hydration sleeve big enough to hold a 3-liter water bladder. The specifications say that this pack has dual side hydration ports, but my sample pack did not have them. Rather, there was a slit connecting to the backpanel cavity and its one top/center hydration port.

When you add in the capability of the side pockets to carry water bottles, this pack has copious water-carrying capacity - as much as 10 liters - making it especially suitable for desert hikers or adventure racers. I personally liked to put my hydration bladder in the backpanel cavity because it saved room in the main compartment and my back kept the water warm in the wintertime.

The outside of the pack is adorned with useful features. There are three large stretch woven pockets on the front and sides that will hold water bottles or an assortment of stuffable items. The side pockets are ample, big enough to hold two slender 1-quart bottles in each one, and you can reach a water bottle with the pack on. A roomy mesh-lined pocket with water resistant zipper at the top of the frontpanel provides secure storage, and has a key clip inside. It’s big enough to hold your lunch. In the same location there are two elastic accessory cords to help attach items to the front of the pack. The mesh hipbelt pockets are bellowed and run the full length of the hipbelt wings; the zippered opening is 8 inches long. The pockets are most useful for smaller and more stuffable items. A compact digital camera will fit, but the mesh pocket does not provide much protection from dirt or weather.

Osprey Stratos 34 Backpack REVIEW - 3
Pockets everywhere, six in all. The top of the frontpanel has a large security pocket with water resistant zipper (top left). The frontpanel stretch-woven pocket (top right) will hold a jacket, and more. There is a large stretch-woven pocket on each side (bottom left), and each one is large enough to hold two slender water bottles. Each hipbelt wing has a full-length zippered mesh pocket (bottom right), providing lots of room for smaller items.

As I mentioned, the Stratos 34 is a panel loader. The front panel zipper is about ¾-height with a double slider. All of the zippers on the pack have Osprey’s new finger loop zipper pulls that are really slick. The frontpanel has Osprey’s Straightjacket compression system, which provides two straps to attach gear to the front of the pack, or extend over the pack to clip to a buckle on the opposite side to compress the entire pack for smaller loads. Each side of the pack has a lower ski loop and upper strap to attach skis or other gear.

With its innovative frame and full-featured suspension system, the Stratos 34 is capable of carrying weighty and bulky loads, and attaching various pieces of gear (skis, snowshoes, snowboard, accessory sack) to the outside. I tested it with loads ranging from 15 to 25 pounds and settled on 20 pounds as a comfortable load carrying capacity (the maximum comfortable load an average person can carry in this pack all day). It’s well designed and highly versatile. It easily handled every task I put it to.

So, how does the Stratos 34 compare with the popular Atmos 35? The Atmos has an aluminum alloy frame, smaller internal hydration sleeve, and perforated foam shoulder straps and hipbelt for better ventilation. Its frame is stiffer and may carry more weight, but it has two side compression straps instead of the Straightjacket compression system. The lower compression straps extend over the side pockets, which is a nuisance, and the frontpanel comes to a point near the top, which is a bit funky.

I measured the weights of the Atmos 35 and Stratos 35 (in size medium) at 41.2 and 45.8 ounces, respectively. Bottom line, neither pack is really lightweight, so if weight is your most important factor in choosing a daypack you will probably want to look elsewhere. I personally feel that weight is not the most important factor in choosing a day pack, because you only carry it for one day at a time, and carrying a loaded day pack is good conditioning for backpacking. More important (to me) is selecting a pack that really fits well, carries comfortably, and has all the features I need, while keeping weight to a minimum. Based on these considerations, my choice of the two is the Stratos 34. I like its design and feature set better - it’s a very rugged, user-friendly, and versatile pack.

What’s Unique

The Stratos 34 AirCore frame with tensioned mesh backpanel is an innovative design that really works to provide a form-fitting backpanel with plenty of ventilation.

Recommendations for Improvement

I had to look hard to find any faults with the Stratos 34. It would be nice to have a small strap to hang a water bladder in the mesh backpanel cavity, rather than just dropping it in. It would be nice to have side hydration ports on the main compartment to work with the internal hydration sleeve. Overall, the Stratos 35 is heavier than I would prefer due to the use of heavier fabrics and plastic frame components, but every part is functional and this pack is built to last a lifetime.


"Osprey Stratos 34 Backpack REVIEW," by Will Rietveld. (ISSN 1537-0364)., 2006-03-21 03:00:00-07.