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Osprey Exos Backpack Review

Osprey's new Exos 46 and Exos 58 backpacks are designed specifically for lightweight backpacking, and, at just over 2 pounds, set a new weight standard for an internal frame backpack with a built-in frame. Plus, they're durable and full-featured.

Hightly Recommended

Overall Rating: Highly Recommended

The new Exos 46 and 58 packs are a lightweight backpacker's dream come true. They set a new weight standard and are full featured. Every feature has been scrutinized for weight and functionality. I found a lot to like while testing the Exos; my nitpicks are few, and most will likely be corrected in the production model.

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by Will Rietveld |


Osprey Exos Backpack Review - 1
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)

  Sizes Available

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

  Frame Material

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.

Osprey Exos Backpack Review - 2
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.

Osprey Exos Backpack Review - 3
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.

Osprey Exos Backpack Review - 4
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).

Osprey Exos Backpack Review - 5
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).

Field Testing

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.

Osprey Exos Backpack Review - 6
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.

Osprey Exos Backpack Review - 7
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.

What's Good

  • 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.


"Osprey Exos Backpack Review," by Will Rietveld. (ISSN 1537-0364)., 2008-11-25 00:10:00-07.


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Osprey Exos Backpack Review
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Addie Bedford
(addiebedford) - MLife

Locale: Montana
Osprey Exos Backpack Review on 11/25/2008 15:03:50 MST Print View

Companion forum thread to:

Osprey Exos Backpack Review

Timothy Cristy
(tcristy) - F

Locale: Ohio
Relative size on 11/25/2008 19:53:21 MST Print View

Will, how does the total storage space of each compare to your Comet? I have a SMD Starlite that works great for winter, but is much too large for my summer loadout. I am trying to decide which size Exos to try, so knowing whether they have more or less space than your Comet would help answer that question.


Joe Clement
(skinewmexico) - MLife

Locale: Southwest
Exos on 11/25/2008 20:19:25 MST Print View

So this thing carries the same weight a Mariposa Plus, Comet or Pinnacle does, but weighs and costs quite a bit more. So are all the pockets, and the trampoline really worth the difference?

Ashley Brown
(ashleyb) - F
Re: Exos on 11/25/2008 20:25:12 MST Print View

> So are all the pockets, and the trampoline really worth the difference?

The other major difference is that the exos has an internal frame for supporting the load. The others you mention are frameless packs.

Ashley Brown
(ashleyb) - F
Re: Osprey Exos Backpack Review on 11/25/2008 20:28:19 MST Print View

Will, thanks for the review.

Quick question on the fabrics. How are the 70d x 100d shadow-check and 160d x 210d window rip-stop fabrics distributed (is one of them orange and the other grey?). Would you say that this pack is of comparable durability to one made by ULA (with dyneema gridstop)?

Huzefa Siamwala
(huzefa) - M
Re: Re: Exos on 11/25/2008 21:29:07 MST Print View

>The other major difference is that the exos has an internal frame for supporting the load. The others you mention are frameless packs.

One can argue that Mariposa plus and Comet are internal frame packs. I think using sitpad with Mariposa would give some ventilation too.

Harlan Bruce
(gbruce) - F

Locale: DFW MetroPlex
Pinnacle pack loads on 11/25/2008 21:50:56 MST Print View

I have carried 30-32 lbs comfortably in my Pinnacle pack a couple of times with no trouble at all. The lack of frame does not seem to be a problem to me.

I would not temp fate by trying any more.

As I improve my gear selection for milder weather, my weight is dropping off, and I should be down to about 25 lbs for next summer's trips. I refuse to sleep on a foam pad. :-)

Roleigh Martin
(marti124) - MLife

Locale: Moderator-JohnMuirTrail Yahoo Group
How well would a Bearikade Cannister pack in the largest Exos pack? on 11/25/2008 23:24:07 MST Print View

Would a Bearikade Weekender Cannister lay horizontally in the largest Exos pack? (It barely does in the Granite Gear Vapor Trail). How would the Bearikade Expedition Cannister fit vertically in the pack?


Mark Verber
(verber) - MLife

Locale: San Francisco Bay Area
Re: How well would a Bearikade Cannister pack in the largest Exos pack? on 11/25/2008 23:44:26 MST Print View

The weekender fits nicely into the Exos 58 vertically... something that it didn't do with the Atmos 50. I didn't try it horizontally because I never use it that way... but I think it might fit.

Roleigh Martin
(marti124) - MLife

Locale: Moderator-JohnMuirTrail Yahoo Group
Re: How well would a Bearikade Cannister pack in the largest Exos pack? on 11/25/2008 23:48:06 MST Print View

Mark, do you have the largest Exos pack to give it a try? What I hate about vertical placement of the Bearikade is the hassle of how to make use of the space around the cannister, while laying it horizontally, no space is wasted as it consumes the whole circumference of the pack at that point in the pack.


Mark Verber
(verber) - MLife

Locale: San Francisco Bay Area
Re: Re: How well would a Bearikade Cannister pack in the largest Exos pack? on 11/26/2008 07:34:09 MST Print View

A friend of mine has one. He lives in a difference city. I got to play with it a bit but don't have regular access to it or any real experience yet. I can give him a ring and see if he can try it... though I don't remember if he owns a bearicade or not. I know he has a bearvault he could try.

For me, the canister vertically has worked well because I have some long and reasonable thin items that go up the sides next to the canister, and I like being able to access the contents of the canister without taking it out of the pack.


Jim Colten
(jcolten) - M

Locale: MN
Re: Pinnacle pack loads on 11/26/2008 08:48:06 MST Print View

I have carried 30-32 lbs comfortably in my Pinnacle pack a couple of times with no trouble at all.

That's encouraging (am waiting for a used Pinnacle to arrive).

I should be down to about 25 lbs for next summer's trips. I refuse to sleep on a foam pad. :-)

Maybe that new thermarest due out in spring will help that situation. But you'd better start saving now, not inexpensive.

Roleigh Martin
(marti124) - MLife

Locale: Moderator-JohnMuirTrail Yahoo Group
Re: Re: Re: How well would a Bearikade Cannister pack in the largest Exos pack? on 11/26/2008 09:02:00 MST Print View

Mark, I'm curious -- we all pretty much pack much the same stuff. What is your long and thin stuff that goes alongside the cannister?

Jean Rogers
(Boonga) - M

Locale: Northwest
Sizes seem made for men not women on 11/26/2008 09:14:48 MST Print View

Too bad the fit isn't adjustable. My torso size - 17.5" would put me in the "small" size, but my hips are no where near "31." Osprey should realize that women are made differently and we have larger hip sizes for a reason. Also, after having numerous children, not all of our waist sizes return to our college size. Women are really getting into lightweight backpacking, so Osprey - don't forget about US.

Mark Verber
(verber) - MLife

Locale: San Francisco Bay Area
Re: Re: Re: Re: How well would a Bearikade Cannister pack in the largest Exos pack? on 11/26/2008 11:07:50 MST Print View

>What is your long and thin stuff that goes alongside the cannister

On one side it is shelter (typically gg the one) and on the other a ba clearview. Both are folded to be the same length as the bearicade and go into the corners nearest to my back. Then the bearicade goes in.


Roleigh Martin
(marti124) - MLife

Locale: Moderator-JohnMuirTrail Yahoo Group
Re: How well would a Bearikade Cannister pack in the largest Exos pack? on 11/26/2008 14:37:27 MST Print View

Mark, what is a "BA Clearview"? Thanks!

I figured it out -- it is this, right?

Edited by marti124 on 11/26/2008 14:38:09 MST.

Roleigh Martin
(marti124) - MLife

Locale: Moderator-JohnMuirTrail Yahoo Group
Will, what does "hip larger than 33 in (84 cm)" mean? on 11/26/2008 14:44:51 MST Print View

I'm not used to seeing backpacks go by anything other than torso length. What does "hip larger than 33 in (84 cm)" mean? That is not waist, correct? How does one measure that and what if the hip says "long" but torso length says "medium", then what does one get?


Will Rietveld
(WilliWabbit) - MLife

Locale: Southwest Colorado
Response to Exos Questions on 11/27/2008 12:07:59 MST Print View

Hi all. Looks like there's lots of good discussion on the New Osprey Exos backpacks. I would like to add a few comments:

Timothy, the Exos 46 is approximate equivalent in volume to the SMD Comet. As you know the actual usable volume of a pack can vary, despite the stated volume. I find the Exos 46 and Comet to have enough volume for a typical lightweight backpacking trip, and can be stuffed to carry the extra food for an extended trip. I managed to get food and gear for an 8-day trip into the Exos 46.

Joe, comparing the Exos with the GG Mariposa, SMD Comet, and GoLite Pinnacle is comparing apples and oranges. I put packs with removable stays into a separate category. With stays in they have an internal frame, but they don't have the comfort and real load carrying capacity as a pack with a built-in internal frame, like the Exos. For a little extra weight you get more comfort. It goes up from there, eg with a Granite Gear Nimbus Meridian you get still more comfort with a little more weight, etc.

Ashley, I would judge the fabrics in the Exos packs adequately durable for lightweight backpacking, with heavier fabrics and reinforcements in wear and stress areas as needed. But they are not as tough as Dyneema Gridstop.

Roleigh, I don't have a Bearikade, so I can't give you a definitive answer. The reason for the hip sizing is the bottom of the pack's frame is contoured to cradle your hip, so they list the maximum hip size each pack will fit.

Best, Will

Bruce Grant
(smartass) - MLife

Locale: Pacific NW
Hardrock on 11/27/2008 17:51:52 MST Print View

Will, your comments on the pack are much appreciated at this point. I have both an Atmos 50 for bigger loads and a Talon 30 for lighter ones. While I find the Talon to be excellent, I was never happy with the fit of the Atmos nor how much main bag space is lost with the angled frame. I was looking for a potential replacement, and it sounds like waiting for the release of the Exos was well worth it. It is also good to see that the Exos does not suffer the same problem as both other pack models, with the side pockets being truly accessible with no compression strap running across them.

As an aside to this excellent review - as one of the runners in the Hardrock 100 this year, thanks so much for volunteering!! It sounds like you were at the Pole Creek station? You should have had the Exos pack plopped close to the goodie table; if it caught my eye I probably would gladly have given up a few minutes of race time to ask a few questions about it :-) I truly appreciate you taking time to volunteer and help the runners. Sometime I'd like to spend six days doing 100 miles of trail in beautiful Colorado like you did instead of 30-something hours ;-)

Delta, BC

Fred eric
(Fre49) - MLife

Locale: France, vallée de la Loire
exos on 12/04/2008 01:10:54 MST Print View

I cant wait to see this pack released
i curently own a stratos 32 and an atmos 50.
they are the only packs i can use with the state of my back ( was lucky to survive a speeding car vs bicycle accident )
i cannot for exemple use a talon 44 with a moderate load (6-8kg ).

while the atmos is very confortable, its a pain to get the hottest of my 2 sleeping bag in it
and the maximum i am able to stuff on top of the bag is one week of food.

I am planning a 10 days hike in Greenland next summer, so maybe one of those 2 bags is the solution instead of buying another sleeping bag.
And i would save 300G at leaston the backpack weight.

By looking at the one before last photos, i am impressed by the volume of the 46l one, it looks like it would hold more stuff than my 50l atmos.
I will definitly need to have a look at the 2 bags before choosing.