The Zpacks Arc Haul Ultra 60L Backpack is an ultralight, ventilated, and adjustable-length backpack made with Ultra, a woven fabric made from Ultra High Molecular Weight Polyethylene (UHMWPE) fibers that is ultralight, waterproof, and more durable than Dyneema DCF. Weighing 21.7 oz (varies slightly by size), the Arc Haul Ultra 60L is set up like most ultralight-style backpacks with a roll-top closure, front mesh pocket, and side water bottle pockets. But what sets this pack apart from other ultralight backpacks, besides its incredibly lightweight and ventilated, suspended-mesh back panel, is a user-adjustable frame that lets you adjust the torso length based on your personal measurements.
Specs at a Glance
- Weight: 21.7 oz (actual weight – medium torso, large hipbelt)
- Gender: Unisex (women’s model available)
- Color: Blue (reviewed), Grey or Black
- Pockets: 3 (hip belt pockets are available as an add-on purchase @ $32.95 each)
- Hydration compatible: No
- Adjustable Torso Length: Yes
- Ventilated (Suspended Mesh): Yes
- Seam-taped: Yes
- Bear canister compatibility: Bearvault BV500 fits vertically while the BV475, BV450, and BV425 all fit horizontally in the bottom of the main compartment.
- Volume: 60L (47L main body, 2.5L each side pocket, 8L center pocket)
- Fabric: Ultra 100, Mesh (front pocket), spacer mesh (shoulder strap/hip belt padding)
- Max Recommended Load: 40 lbs (we rate it closer to 30 lbs)
Backpack Storage and Organization
The Zpacks Arc Haul Ultra 60L is designed like most ultralight-style backpacks with a large main compartment, front mesh pocket, and side water bottle pockets. The main compartment closes with a roll-top with a stiffener in the top to make it easier to roll. While the roll top can be secured on top of the pack by clipping the two sides together, Zpacks also sells buckles and webbing straps along the sides (easily removable), so you can compress your load more effectively. A single strap runs over the roll-top to secure it. The interior is seam-taped, making the backpack highly water-resistant, although we’d still recommend lining it with a plastic bag or pack liner.
The size and shape of the main compartment narrow in the middle of the pack where the pack’s curved frame is arched to create a ventilation cavity. This is true of most ventilated backpacks. When the back of the pack behind your torso curves inward, it loses width and items can be harder to pack or unpack, since you have to reach around the resulting bulge. However, the Arc Haul Ultra 60 can hold a BearVault 500 vertically and the BearVault 475, 450, and 425 sizes horizontally in the bottom of the main compartment.
The front mesh pocket is made with a non-stretch mesh and has an elastic top. It can hold quite a lot of stuff at once and it’s easy to see what’s inside so you know you haven’t misplaced anything. The mesh fabric is comparatively lightweight and less robust than the heavy-duty diver’s mesh that some other manufacturers are currently using to improve durability. An earlier version of the Arc Haul Ultra 60 had a Lyra mesh front pocket, but the newer mesh one is much easier to see through since the weave is more open.
The side water bottle pockets are made with Ultra fabric with drain holes at the bottom and provide excellent durability. They’re large enough to hold two SmartWater bottles, but you can only get one 1L Nalgene into them. They also have non-adjustable elastic running through the top to keep bottles from falling out. While they’re reachable when the pack is worn, the elastic can make it a little challenging to get a bottle back in if you’re carrying anything else in the pockets. That’s not a showstopper, just an observation about the structure and capacity limitations of the side pockets (and my current level of shoulder flexibility).
The Arc Haul Ultra 60L does not come with hip belt pockets and they’re an add-on purchase at $32.95/each. They are attached with an elastic band and hooks to the hip belt, which has daisy chains sewn on its exterior. The daisy chain can also be used to secure third-party pockets to the hip belt. I don’t use hip belt pockets with this pack and I don’t really miss them all that much, although I do attach an accessory pocket to one of the shoulder straps to hold my phone.
The pack is not hydration compatible if that matters to you. There is no internal hydration pocket or hook to hang a reservoir. There are also no hydration ports in the pack body to run a hose in order to keep the interior as waterproof as possible. If you use a hydration system you must run a hose out the side of the rolltop.
Backpack Frame and Suspension
The Zpacks Arc Haul Ultra 60L has a ventilated, trampoline-style frame that lets air flow behind your back so you stay cooler and perspiration dries faster. This makes backpacking much more pleasant in hot and humid conditions. Zpacks is unique amongst UL pack manufacturers in offering this type of frame. While other manufacturers, like Osprey, Gregory, and Deuter offer a similar capability, theirs is much more tightly integrated and encapsulated than the Arc Haul Ultra 60 frame which is completely visible and externalized. But then again the Arc Haul Ultra is substantially lighter weight.
While this gives the Arc Haul Ultra a somewhat Frankenstein-like appearance with all kinds of straps and rods, it’s designed this way on purpose to keep the pack weight as low as possible. The closest comparable ultralight ventilated backpacks, the Osprey Exos 58 Pro or Gregory Focal 58, weigh about 50%-100% more than the Arc Haul Ultra, although the latest Osprey Exos Pro now has an adjustable length torso.
The Arc Haul Ultra frame is quite simple. There are three horizontal crossbars, positioned along the top, middle, and base of the pack bag. Two curved carbon fiber rods are attached to the corners of the top and bottom bars and a mesh back panel is connected to them with webbing straps. The carbon fiber rods form an arc, with the mesh suspended over it. The middle crossbar keeps the pack bag from collapsing backward and filling the cavity created by the arc while protecting your back from objects with hard edges like a bear canister. The backpack’s shoulder straps and load lifters are connected to the top crossbar, while the hip belt is attached to the bottom crossbar. It’s as simple as that.
Adjustable Torso-length
The Arc Haul Ultra frame has an adjustable length torso capability, which lets you raise or lower the top of the shoulder straps up to 4″. This can make a huge difference in the fit of the backpack and its load-to-hip transfer. That and the ventilated mesh back panel are unique amongst cottage ultralight pack makers. They’re also patented which is why other brands don’t use the same system.
The torso adjustment mechanism is also quite simple. The shoulder straps are connected to two vertical interior webbing straps that are connected to the top crossbar and at points just above the middle crossbar. If you push the top of the shoulder strap down to lower it, you shorten the distance between the hip belt and the top of the strap, thereby shortening the pack’s torso length. If you raise the strap, you lengthen the torso length. It’s important that you keep two shoulder strap heights the same, so one shoulder doesn’t do more work than the other. The actual amount of torso length adjustment used is best done by feel while wearing a loaded backpack. See the Zpack’s pack fitting video on the Sizing tab for more details.
Comfort
Weight
Suspension
Features
Adjustability
Sizing
Durability
Comfortable Ventilated Backpack
Shoulder straps
Zpacks uses S-shaped shoulder straps on their packs, which are better for men and women because they wrap around the pecs rather than smash them flat, like the J-shaped straps found on other unisex backpacks. The straps are not sewn directly to the crossbars or the pack bag but are attached by a webbing strap that permits the top of the pad to rotate and conform to the shape of your shoulders for a more personalized fit. The shoulder straps are lightly padded and covered with wicking spacer mesh. The exteriors have daisy chains sewn on the front that make it possible to attach accessory pockets or reposition the sternum strap.
Hip belt
The Arc Haul Ultra hip belt is available in a variety of lengths so you can get a good fit. It’s also replaceable, which is nice if you gain or lose weight and want to change size. The hip belt also has exterior daisy chains suitable for attaching accessory pockets although none are included with the base backpack.
The hip belt is female-friendly because it has upper and lower webbing straps that can be used to create a differential fit and accommodate curvy female hips or flattish male ones. The hip belt is lightly padded, which you’d expect on an ultralight backpack used to carry lighter loads. It provides a great hip wrap that doesn’t slip or buckle when you load the pack up with extra weight. It’s lightly padded relative to heavier Osprey or Gregory backpacks, but perfectly comfortable with loads of 30 pounds or less.
Load rating
While the Arc Haul Ultra 60L has a frame, its primary function is ventilation and doesn’t substantially increase the load-carrying capacity of the pack. I’ve carried multi-day loads with the Arc Haul Ultra 60L and find that the maximum comfortable load including gear, food, and water is about 30 pounds. I don’t think it’s all that comfortable with more, but you can certainly carry more for a long water carry if you have to. With a 13-15 lb base weight, I can carry 4-6 days of food and water quite comfortably. Zpacks rates the pack’s max recommended load much higher at 40 lbs, but I wouldn’t say it’s very comfortable with that much weight.
Backpack Compression and External Attachment System
The Arc Haul Ultra 6oL is fairly light on compression capabilities and attachment capabilities but provides room for you to expand on them if you wish to customize them.
In addition to roll-top, which provides top-down compression, the Arc Haul Ultra has a static cord-based side compression system that’s tensioned with line locks. There are also sleeping pad attachment cords at the base of the pack, which is a nice feature, not found on most UL backpacks. The same cord system can also be used or modified to carry an ice ax or even trekking poles, using the side compression cords to secure the shafts.
If you want to replace the compression “cords” with heavier-duty webbing, that is easy using gatekeeper clips by sliding them into the webbing tabs sewn into the pack’s seams. For example, I prefer wider horizontal webbing straps when attaching snowshoes to the side of my backpack because they are easier to adjust when wearing gloves and provide better holding power.
Ultra Fabric
Ultra is the latest ultralight waterproof wonder fabric for making backpacks because it is more resistant to abrasion than Dyneema DCF in laboratory tests. I’ve been using an earlier version of the Zpacks Arc Haul Ultra 60 for over a year and my field experience agrees with those findings, even for hiking in New Hampshire’s White Mountains where “backpacks go to die.” New Hampshire granite rips the crap out of backpacks made of Robic nylon and wears down the outer polyester layer used on non-woven Dyneema DCF backpacks causing them to pile and fray. But there is no sign of external wear on the Zpacks Ultra packs I’ve been using which is very impressive given our local conditions. Actually, it’s kind of incredible.
Like all new backpack fabrics, Ultra has evolved since it first became available. In this latest version of the Arc Haul Utra 60, the pack is newly available with a blue face fabric (in addition to black and grey) while the inner laminated waterproof layer is much thicker than on previous versions of the pack. When hiking in the rain, the blue face fabric gets visibly wet, but no moisture leaks inside the backpack which is also seam-taped. I’d still recommend using a pack liner or at least a stuff sack for your sleep insulation.
Comparable Ultralight Backpacks (with Frames)
Recommendation
The Zpacks Arc Haul Ultra 60L is an ultralight ventilated and adjustable-length backpack designed for multi-day backpacking trips and thru-hiking. Weighing just 21.7 oz, it’s significantly lighter weight than comparable backpacks even though it has a much more sophisticated and adjustable length frame system. Once you’ve dialed in the fit, the backpack carries like a dream, comfortably transferring loads to the hip belt while keeping your back cool and dry. I really enjoy using this pack, especially in hot weather, where the suspended mesh frame keeps me much drier, cooler, and more comfortable. If you’re trying to significantly reduce the weight of your backpacking gear and want a ventilated backpack, I’d recommend getting the Zpacks Arc Haul Ultra 60L.
If there’s a downside to the Zpacks Arc Haul Ultra 60L, it’s the price. The base pack costs $399 and while that buys you a very durable Ultra backpack, it’s still a huge chunk of change. After that, Zpacks charges extra for accessories like hip belt pockets, a top Y-strap, external shock cord, roll top closure straps, trekking pole holsters, and ice axe loops, which are included for free with most other backpacks. While you can jury rig most of these for much less or buy them elsewhere, it complicates outfitting a Zpacks backpack and increases the cost.
Disclosure: Zpacks donated a backpack for this review.
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