Before the storm. The new for spring 2009 Osprey Exos 46 (shown) and 58 packs will weigh just over 2 pounds and are full-featured.
We have previously reviewed the Osprey Aether and Atmos backpacks and found their feature set much to our liking, but their weights pushed our upper limits, and we could barely call them "lightweight." Osprey is solidly re-entering the lightweight backpack competition with its new Exos pack, which is a brand new pack series specifically designed to be lightweight. The Exos packs will be available in spring 2009 in 34, 46, and 58 liter volumes.
|2009 Osprey Exos 46 and Exos 58|
|Built in internal frame, top loading with floating top pocket|
|Exos 46 is 2800 cu in (46 L)
Exos 58 is 3500 cu in (58 L)
|Size M tested. Measured weight: Exos 46 2 lb, 3.3 oz (1 kg), Exos 58 2 lb, 6.5 oz (1.1 kg)
Manufacturer specification: Exos 46 1 lb, 14 oz (845g), Exos 58 2 lb, 3 oz (997g)
|Unisex S, M, L|
Torso Fit Range
|Small fits torso less than 18.5 in (47 cm), hip less than 31 in (79 cm)
Medium fits torso between 18.5 – 20.5 in (47-52 cm), hip between 30 – 34 in (76-86 cm)
Large fits torso longer than 20 in (51 cm), hip larger than 33 in (84 cm)
|70d x 100d shadow-check and 160d x 210d window rip-stop|
|6061-T6 aluminum, polycarbonate cross piece|
|Floating top pocket with zippered access and zippered mesh map pocket on the underside, stretch pocket for MP3 player or small GPS on shoulder strap, two mesh side pockets with top and side access, large front stretch-woven kango pocket, two mesh hipbelt pockets, full width front compartment under kango pocket with zippered access on both sides (one side on the Exos 46), two front tool holders (one on the Exos 46), four side compression straps, one top compression strap, two ice axe loops, two sleeping pad loops, Stow-on-the-Go trekking pole attachment, AirSpeed mesh backpanel, load lifters, adjustable sternum strap with whistle, ErgoPull hipbelt, 3L internal hydration sleeve with two hose ports|
Volume To Weight Ratio
|79.3 ci/oz for the Exos 46, 90.9 ci/oz for the Exos 58 (based on 2800 and 3500 ci, respectively, and measured weights of 35.3 and 38.5 oz, respectively)|
Maximum Comfortable Load Carrying Capacity
|30 lb estimated comfortable load for an average person carrying the pack all day|
Carry Load to Pack Weight Ratio
|13.6 for the Exos 46 and 12.5 for the Exos 58 (based on 30 lb and a measured weight of 2.21 and 2.41 lb, respectively)|
|Exos 46 US$179
Exos 58 US$219
Suspension System and Features
Although the Exos was designed to be lightweight, it borrows a lot of design elements from Osprey’s current Talon and Atmos backpack lines. Every component was optimized for light weight and functionality. It’s rather amazing that a backpack with a built-in frame can be so light and at the same time have so many features (see the list in the Specifications section).
This review covers both the Exos 46 and Exos 58 backpacks, which differ mainly in volume. The feature set is nearly identical on the two packs, with only a few small differences.
Views of the Osprey Exos 58 (and 46). The frontpanel view (top left) shows the pack’s large front stretch-woven kango pocket and dual tool loops. The pack’s AirSpeed backpanel (top right) is a trampoline type for increased ventilation. There is even a small pocket on one shoulder strap for an MP3 player. A side view (bottom left) shows the pack’s large mesh pockets with top and side entry and narrow compression straps that will also attach items to the side of the pack. The top view (bottom right) reveals a zippered mesh map pocket under the top cap, top compression strap (orange), and drawcord closure.
The new AirSpeed mesh backpanel on the Exos packs is not as deep as previous versions. The gap is about 1 inch, enough to provide good ventilation without interfering with pack volume or the pack’s center of gravity. The peripheral contoured tubular frame is 6061-T6 aluminum.
At first look, Osprey’s BioStretch (mesh covered slotted foam) shoulder harness (left) and hipbelt wings (right) seem thin and inadequate, but the suspension system performed well with moderate loads (see my field testing section below).
The peripheral tubular aluminum frame of the Exos is curved to wrap around the hips. Hipbelt wings and shoulder harness (see photo in previous panel) are attached to the backpanel mesh rather than the frame. This is not a design intended to carry heavy loads.
The Exos packs do NOT have an adjustable torso length like many larger Osprey packs. Rather, the shoulder straps and hipbelt wings are sewn to the backpanel and the only adjustment available is to lengthen or shorten shoulder straps and load lifters. Getting a proper fit is a matter of choosing the proper pack size. The Exos will be available in unisex sizes small, medium, and large (torso fit ranges are listed in the Specifications section).
During summer 2008, I tested both the Exos 46 and 58 on numerous backpacking trips carrying a wide range of loads. I tested the Exos 58 (58 liters) first, assuming it would be the optimum size for lightweight backpacking. However, using typical lightweight backpacking gear and loads in the 25- to 30-pound range, I was never able to completely fill it up. The Exos 58 has a lot of room! It has eight separate pockets, so a large portion of my gear fit in the pockets alone.
The side mesh pockets on the Exos (left) have a side entry that enables a hiker to reach and replace a water bottle without taking the pack off. My favorite feature on the Exos pack is the large zippered compartment under the kango pocket on the frontpanel (right). The Exos 58 has zippered access on both sides, while the Exos has access on only one side. The pocket will hold numerous frequently needed items and make them easily accessible on the trail.
On one occasion, while volunteering for the Hardrock 100 Endurance Race, I used the Exos 58 to carry in 40-pound loads of supplies and food to a remote aid station, climbing 1000 feet over a three mile distance. The pack carried the weight just fine without popping a seam and transferred the majority of the weight to my hips, but I had to tighten the hipbelt really tight to keep it from slipping off my hips.
Although the Exos 58 carried moderate (25 to 30 pounds) loads comfortably, the heavier loads described above are beyond its comfort range, except for hikers with strong shoulders. Thus, for summer backpacking, the Exos 58 seems to have too much volume for its weight carrying capacity. On the other hand, the Exos 58 would be an excellent choice for winter backpacking, where more volume is needed for bulkier insulated clothing and gear.
Realizing that the Exos 58 was a bit too roomy for me, I tested the Exos 46 during the second half of the summer. Although 46 liters seems small, I found the volume to be closer to my needs for summer backpacking. On a six-day, 100-mile backpacking trip on the Continental Divide Trail, I was able to get all of my gear and eight days of food (31 pounds initial weight) into the Exos 46. It carried the weight comfortably enough, but I was happier when pack weight dropped under 25 pounds. It would help if the shoulder straps were a little wider to distribute the weight more.
My carry load tests closely agree with Osprey’s recommended maximum carry weights of 20 to 30 pounds for both the Exos 46 and 58. Bottom line, the Exos backpacks are not designed or intended to carry heavy loads. My field testing confirmed that.
Exos 46 on the Continental Divide Trail in Colorado. Because of its numerous pockets, the pack has more room than its 46-liter size would indicate. The Exos also carried well on day-length trips from a base camp (right).
The Exos is a brand new pack model, and it’s remarkable that Osprey got most of the details right on the first try. In spite of its light weight, the Exos is loaded with features. I found it rather amazing that an internal frame backpack weighing slightly over 2 pounds can have so many features (including eight pockets!) and durable fabrics.
Osprey states "The Exos Series was designed with the knowledge that, in the long run, going light with a pack that has no suspension burns more energy than is gained by ounces saved." If they are referring to a frameless backpack, I personally would never carry 20- to 30-pound loads in a frameless pack. Granted, some frameless packs, like the GoLite Pinnacle and Jam2 are capable of carrying heavier loads more comfortably, but the updated Pinnacle and Jam2 for spring 2009 will weigh 2 pounds and 1 pound, 10 ounces, respectively – nearly as much as the Exos. My current pack of choice to carry 20 to 30 pounds is the Six Moon Designs Comet (27 ounces, $170 with stays) that has removable stays, but again the Comet weighs nearly as much as the Exos and does not have the feature set of the Exos. Needless to say, the Exos is now my pack of choice for carrying 20- to 30-pound loads.
However, the Exos is not quite perfect, and I have a few small issues to mention here, which hopefully will be addressed in the production pack.
- The side mesh pockets are way too tight (see photo above), so they will not hold much when the main compartment is fully expanded
- The sternum strap is adjustable, but I found its lowest setting to still be too high
- The load lifter straps slip some; I needed to tighten them about twice a day
- I didn’t have much use for the sleeping pad straps on the bottom of the pack, and they catch on branches while bushwhacking (Osprey says they can easily be cut off.).
Overall, I’m very impressed with the new Osprey Exos backpacks. This is a pack designed from the ground up for lightweight backpacking, assuming you want a pack that has room for everything and plenty of organizing and convenience features. The Exos will carry a 20- to 30-pound load with comfort and is capable of carrying up to 35 pounds when necessary. Both packs have more room than their size (46 or 58 liters) would indicate, so be sure to take that into account when choosing which one to get.
- Sets a new weight standard for a built-in internal frame backpack.
- Mesh backpanel provides ventilation and does not interfere with pack volume or center of gravity.
- Lightweight, durable fabrics and frame material.
- Large stretch kango front pocket is very handy for carrying a wet shelter or stuffing a jacket.
- Contoured tubular frame is very lightweight, yet is capable of complete weight transfer to the hips.
- Numerous pockets for organizing and convenient access.
- Fits well (if you choose the correct size).
- Comfortably carries moderate loads.
What’s Not So Good
- Torso length is not adjustable.
- Side mesh pockets are tight when pack is full.
- Load lifters slip and require retightening.
- Sternum strap is too high.
Recommendations For Improvement
- Lower the sternum strap.
- Bellow the side mesh pockets and increase the size of the top opening.
- Revise the load lifters so they don’t slip.
- Widen the shoulder straps to distribute weight.