The Osprey Exos Pro 55 Backpack is a ventilated and adjustable-length ultralight backpack that weighs 33.2 oz. It’s basically an ultralight redo of the heavier Osprey Exos 58 Backpack, that’s 11.8 oz lighter-weight using recycled fabrics with a few minor changes to the design. Despite the weight reduction, the Exos Pro 55 remains a quite lively and dynamic backpack that is responsive and fun to carry. However, the use of thinner fabrics means that this pack is going to be somewhat less abrasion resistant than the heavier Exos 58, which is something to consider if you’re rough on backpacks.
Specs at a Glance
- Weight: 33.2 oz (size S/M)
- Stripable top lid weight: 2.6 oz
- Volume: 55L
- Closure: Top lid
- Adjustable Torso Length: Yes
- Ventilated: Yes
- Hydration compatible: Yes
- Pockets: 6, plus the main compartment
- Frame: Internal aluminum perimeter frame
- Torso: S/M: 17″ – 20″ (L/XL 21″-23″ also available)
- Hip Belt: S/M: 28″ – 50″ (L/XL 30″-50″ also available)
- Bear canister compatibility: BV500 or Garcia Backpacker’s Cache fit horizontally or vertically in the main compartment. They can also be held in place under the floating top lid pocket.
- Materials: 100D Nylon x 200D UHMWPE ripstop w/DWR treatments made without PFAS
- Maximum recommended load: 30 lbs
Who is the Exos Pro 55 For?
If you already own the heavier Osprey Exos 58, switching to the Exos Pro 55 is an easy way to shave close to 11.8 oz of pack weight while retaining the backpack feel and most of the features you’ve grown used to. The Exos Pro 55 is also a good option for people who want a lighter-weight ventilated backpack but don’t want to give up the convenience of a top lid pocket or the external attachment features found on more conventional multi-day backpacks. While you can switch to a more minimalist roll-top backpack like the ventilated Zpacks Arc Haul Ultra 60, doing so can require a pretty big change in how you pack and interact with your backpack during the day. Whichever way you choose to go, Osprey and Zpacks are still the only pack manufacturers to offer ultralight, ventilated, and adjustable-length backpacks.
How is the Exos Pro 55 different than the Exos 58?
The Exos Pro 55:
- Is 11.8 oz lighter weight than the Exos 58 (may vary depending on sizing).
- Does not have a second pocket under the top lid.
- Does not have separate sleeping pad straps on the front of the pack.
- The front stretch pocket has fabric loops along the sides that can be used to hang gear.
- The front stretch pocket has less mesh and more solid fabric for better durability.
- The left-hand hip belt pocket is open and not zippered.
- The adjustable torso length is secured using small dowels instead of larger plastic discs.
- There is a silicone print at the base of the suspended mesh to prevent slippage.
- The sternum strap only has three positions instead of a sliding rail adjustment.
- The shoulder straps are less padded.
- The shoulder straps only have 1 hydration hose keeper, not two.
- There’s no stow-on-the-go trekking pole holder.
- Uses thinner (200d) fabric in high-wear areas.
Backpack Organization and Storage
The Osprey Exos Pro 55 is very different from most ultralight backpacks because it’s configured with a floating top lid instead of a dry-bag style roll top. With a single large top zippered pocket (with key fob), the floating lid lets you sandwich extra gear between the lid and the top of the pack’s main compartment so you can carry extra technical equipment or supplies that won’t fit inside your pack. Top lids are a great feature, especially when you need to carry bulky gear like bear canisters, rope coils, foam pads, or tent bodies that won’t fit into the main compartment of your pack. The top pocket also provides handy access to hats, gloves, snacks, and navigation gear and is indispensable for cold-weather use.
If you don’t need the top lid on the Exos Pro 55, you can remove it to save gear weight. This reduces the weight of a small/medium Exos Pro 55 by 2.6 ounces bringing it down to a respectable 30.6 oz (1 lb 14.6 oz).
There’s a nylon flap under the top lid that is permanently attached to the pack, what Osprey calls a FlapJacket, that covers the drawstring opening of the main compartment. When you remove the top lid, the FlapJacket is used to protect the main compartment from the rain in its stead. The rear of the FlapJacket clips into the same rear straps and buckles used by the top lid so you’re not left with any extra straps or buckles to get in the way. When it’s not needed you can stuff it into the main compartment or into the internal hydration pocket.
While the Exos Pro 55 also has good open storage in the form of side and front pockets, the main compartment is where the bulk of this pack’s capacity is. With over 3350 cubic inches of room, you can put a ton of gear and food inside. Being a mainstream backpack manufacturer, Osprey computes the volume of their packs using industry norms and only counts covered and zippered storage when they calculate backpack volume. If you are comparing the volume of the Exos Pro 55 with a pack from a cottage backpack maker, be aware that they often add in open and closed pocket volumes so the Exos Pro 55 will feel quite a bit larger and hold considerably more gear.
While the main compartment curves inward to accommodate the shape of the ventilated frame near its base, the main compartment is so large that the pack is still easy to pack. Still, because it is ventilated, you’ll want to position the heaviest items as close to your back and hips as possible. With the exception of a hydration pocket, hang loop, and top compression strap, there’s nothing inside the Exos Pro 55 main compartment like a sleeping bag compartment to break up the seemingly cavernous space. Still, it’s easy to see inside the main compartment because lightly colored fabric panels help channel light to the pack’s interior. I’d still recommend packing the Exos Pro 55 with a pack liner for moisture/rain protection (See Five Ultralight Pack Liners Compared.)
Osprey included hipbelt pockets on the Exos Pro 55 but they’re slightly different than those on the current Exos 58. The left-hand pocket is now open on top and doesn’t have a zipper. I thought I’d hate that, but it’s actually pretty useful for stuffing trash into. The right-hand pocket is still zippered and large enough to fit an iPhone X into along with some snack bars.
But the pockets are sewn onto the hipbelt in such a way that the back of the pocket has to be able to curve when it wraps around your hips…which is a good way to break a SmartPhone screen. I’d advise against putting anything similarly oversized and inflexible into them.
This is the result of the fact that Osprey keeps the hipbelt wings on the Exos Pro 55 and Exos 58 short, so they wrap around the back and sides of your iliac crest (hipbone) but don’t extend more forward to the front like other backpacks. They still provide effective load-to-hip weight transfer, but I personally prefer longer hipbelts because it means the hipbelt pockets are positioned in front of my torso and not along the sides or back of my hips. You do get used to the shorter hipbelt quickly on the Exos Pro 55 and Exos 58, but it is a different approach to hipbelt length and pocket placement than on backpacks from other manufacturers.
In addition to the main compartment, the Exos Pro 55 has two stretch-side mesh pockets that can be used to store water bottles. The mesh is not strong enough for off-trail travel and I would recommend you stay on trails with this pack in order to keep the pockets from tearing. Each pocket is reinforced with solid fabric on the bottom for better durability and has a holster-style opening cut in front, which lets you position bottles sideways so you can pull them out and replace them when on the move.
You can also pack a tall bottle and screwed-on filter in the side pockets, but they aren’t reachable when wearing the pack and tall bottles fall out of the holster pockets if you try to rest them there.
There is also a large stretch stuff-it pocket on the front of the pack which is useful for carrying items that you want easy access to, without requiring that you stop and open your backpack. I can’t live without a stretch pocket like this and use it to stuff light layers or snacks that I want easily accessible during the day. It’s also a good place to stash a wet rainfly, so you can easily pull it out to dry when you stop to admire a view.
Backpack Frame and Suspension
The Osprey Exos Pro 55 is a ventilated suspended mesh-style backpack. Breathable mesh is suspended in front of the back panel creating a ventilated space behind your back that’s designed to evaporate sweat before it can soak your shirt. The mesh is tightly stretched across the 360-degree aluminum frame which also serves to anchor the hip belt and load lifters. The aluminum frame on the Exos Pro 55 is the secret sauce that “makes” this pack. It’s super lightweight and stiff, providing great load transfer to the hips, so you can load up this pack and still get a very comfortable carry. The carry is actually quite amazing, even with a full load.
This new Exos Pro 55 also has an adjustable torso length with 4″ of adjustability that is very lightweight and simple to use. This is a huge benefit for new backpackers who have less experience sizing and fitting a new backpack. You lengthen or shorten the torso length, the distance between your hip bones and your C7 vertebra, by moving the shoulder strap harness up or down since the position of the hip belt is fixed. This is done using a simple dowel and ladder system which slides up and down along the track on the back of the backpack.
The shoulder straps and hipbelt are both covered with a stretchy mesh fabric that is soft and helps wick moisture to prevent rubbing and chafing. The shoulder straps are lightly padded and have one elastic hydration hose keeper strap on the front. However, while the shoulder straps are comfortable, you’ll be somewhat challenged to attach accessory pockets to them, something that is increasingly popular with backpackers and day hikers alike. The same can be said for the lightly padded hip belt.
Unlike the Exos 58, the sternum strap on the Exos Pro 55 can only be positioned at three locations. To adjust it, you need to push the plastic buckles connecting the sternum strap to the shoulder straps through small cord loops to reposition them higher or lower. It takes a little patience to do this but it’s not difficult and makes for a very secure anchor.
The Exos Pro 55 comes in two sizes S/M and L/XL in terms of torso length, while the hip belt length is nearly identical across both sizes (28″-50″ vs 30″-50″), instead of radically different, making it much easier to get a hipbelt that fits you regardless of your torso size.
External Attachment Points and Compression System
The Osprey Exos Pro 55 has two compression straps on each side of the pack. The top strap is anchored on at the top corner of the front stretch pocket and runs to the frame just below the front load lifter, while the bottom strap is configured as a Z crisscrossing over the side water bottle pocket before attaching to the back of the hip belt pocket I’m not a huge fan of the Z-style threading pattern because I think it makes it difficult to strap bulky gear like snowshoes or a folding pad to the side of a pack. I find two horizontal-side compression straps to be optimal instead.
But one thing that’s missing from Exos Pro 55, but is provided on the Exos 58, is a pair of sleeping bag straps for attaching a folding foam pad, like a NEMO Switchback or a Thermarest Zlite pad to the bottom of the pack below the front stretch pocket. This is very difficult to do with the lower Z-Style side compression straps because they’re not long enough to easily fit over one of these folding pads. You can do it, but it requires a lot of effort and makes it very difficult to put anything into the front stretch pocket because the pad is tightly compressed against the pack. I’d recommend rigging up your own elastic cord loops for attaching a pad to the gear loops running alongside the front stretch pocket instead.
You also can’t thread the side compression strap through the side water bottle pocket on the Exos Pro 55 and it can only run on the outside of the mesh pocket. This is because the hipbelt pocket is the anchor for the bottom side compression strap…which is a screwy way to design it because that compression strap will pull the hip belt off your hip if you need to tighten it. These functions are best decoupled.
But don’t let the Z-style straps (which are removable by design) deter you from rigging up two horizontal compression straps instead. One of the great things about the Exos Pro 55 is the distribution of gear loops around the perimeter pockets, the pack bag seams, and even the top lid, making it easy to rig up your own custom compression system with an extra cord lock and some guyline or a piece of webbing. If I used the Exos Pro 55 regularly, I’d probably remove the side compression straps off and replace them with my own cord and cordlocks.
- Lightweight and high-capacity (55 L)
- Dynamic frame that makes loads feel lighter
- Large bear canister fits horizontally
- A lightweight perimeter frame provides great load transfer and control
- Lightly colored fabric strips improve main compartment visibility
- Lots of external attachment points all around the pack
- Difficult to attach accessory pockets to the shoulder straps or hipbelt pockets.
- Difficult to pull tall items out of side pockets while wearing the pack.
- Z-style side compression straps are awkward to use with bulky gear.
- No sleeping pad straps.
Comparable Ventilated (Suspended Mesh) Backpacks
There aren’t many lightweight (sub 3 pound) ventilated backpacks available today, with or without adjustable torso lengths.
|Make / Model||Weight||Adjustable Torso Length|
|Osprey Exos 58||2 lbs 13 oz / 1276g||Yes|
|Osprey Exos Pro 55||2 lb 1.2 oz / 941g||Yes|
|Gregory Focal 58||2 lbs 9.3 oz / 1171g||No|
|Zpacks Arc Blast 55||1 lb 3.9 oz / 565g||Yes|
|Zpacks Arc Haul Ultra 60||1 lb 3.6 oz / 556g||Yes|
Zpacks also has several models that are very competitive with the Exos Pro 55 including the Zpacks Blast 55 (See our Zpacks Blast 55 Review) and the Zpacks Arc Haul Ultra 60 (See our Zpacks Arc Haul Ultra 60 Review.) While both of these packs are much lighter than the Exos Pro 55, they’re also much more expensive. On the other hand, if you want a ventilated backpack with an adjustable torso length that’s set up like an ultralight roll-top pack, they’re the only game in town.
The Osprey Packs Exos Pro 55 Backpack is a top-loading backpack with an adjustable torso length that’s easy to fit and configure for many different kinds of hiking and backpacking trips. Weighing just 2 pounds 1.2 ounces, it boasts a reinforced perimeter-style aluminum frame and ventilated suspension that provides excellent comfort and control for loads up to 30 pounds. If you want a large but ultralight (55L) hydration-compatible backpack with a real frame and a top lid, the Exos 55 Pro is a great choice that’s designed for multi-day backpacking, thru-hiking, and section hiking.
The thing that I like less about this pack is the way it forces you to pack a certain way when it comes to carrying water bottles, adding accessory pockets, or strapping gear to the outside of the backpack. I prefer more flexibility in this regard, but that’s my personal preference. Despite that, I could see being perfectly happy using an Exos Pro 55 for a long-distance or section-hiking backpacking trip, particularly in hot and humid weather where a ventilated suspended mesh frame is a huge win.
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