SectionHiker.com Backpacking Gear Reviews and FAQs 
The Zpacks Arc Haul Ultra 60L Backpack is an ultralight, ventilated, and adjustable-length backpack made with Ultra, a new woven fabric made from Ultra High Molecular Weight Polyethylene (UHMWPE) fibers that is ultralight, waterproof, and more durable than Dyneema DCF. Weighing 19.6 oz, 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: 19.6 oz
- Gender: Unisex, but very female-friendly (see below)
- Pockets: 3 (hip belt pockets are available as an add-on purchase @ $32.95 each)
- Hydration compatible: No
- Ventilated: Yes
- Seam-taped: Yes
- Bear canister compatibility: Yes – Vertical inside
- Volume: 60L (47L main body, 2.5L each side pocket, 8L center pocket)
- Fabric: Ultra 100 and 200, Lycra (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 shaped 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 and has a narrow velcro-stiffener on top. 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 is significantly altered when a pack’s 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. Packing your gear around a full-sized bear canister can also be challenging
The front mesh pocket is made with a Lycra 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 mesh that other manufacturers are currently using to improve durability.
The side water bottle pockets are made with heavier-duty 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 makes 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.
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 pockets are also available in Dyneema DCF or Robic Nylon for slightly less. The daisy chain can also be used to secure third-party pockets to the hip belt.
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.
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, externalized, and adjustable by the end-user.
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 downside is that the pack makes a little noise when hiking as the parts rub together. The closest comparable ultralight ventilated backpacks, the Osprey Exos 58 or Gregory Focal 58, weigh about twice as much as the Arc Haul Ultra, although the latest (2022) Osprey Exos now has an adjustable length torso. Both these packs are also quieter to carry because the frame is internal and all one piece.
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 was an adjustable length torso capability, which lets you raise or lower the height 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.
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 and after the arc depth has been set. See the Zpack’s pack fitting video on the Sizing tab for more details.
Dialing in a really good fit can require some experimentation with different hip belt heights and torso length adjustments: some people prefer the hip belt to rest on the iliac crest, while others like it higher or lower. Though the fact that you can personalize the fit with this pack, speaks volumes.
Zpacks Arc Haul Ultra 60
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 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. Zpacks rates the pack’s max recommended load much higher at 40 lbs, but that 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 a line lock. 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 webbing straps when carrying a fishing rod or attaching snowshoes to the side of my backpack because they are easier to adjust and provide better holding power.
Ultra Fabric
Ultra is being heralded as the new ultralight waterproof wonder fabric for making backpacks because it is more resistant to abrasion than Dyneema DCF in laboratory tests. I think the jury is still out on whether that’s true in the real world too. I’ve managed to wear out or destroy backpacks with every new ultralight backpack fabric that’s been introduced in the past 15 years; I’ll let you know how Arc Haul Ultra 60L is holding up to New Hampshire hiking and backpacking in about 2 years. Of course, by that time, it will probably have been replaced by something that’s supposedly even better. Whatever the case, don’t buy this backpack solely to have one made with Ultra. Buy it for its functional strengths and adjustable fit – which are both superb.
Comparable Backpacks
| Make / Model | Weight | Ventilated | Adjustable Torso |
|---|---|---|---|
| Gregory Focal 58L | 41.3 oz / 1171g | Yes | No |
| MLD Exodus 58L | 18 oz / 510g | No | No |
| Osprey Exos 58L | 45 oz / 1276g | Yes | Yes |
| Osprey Levity 60L | 31.2 oz / 885g | Yes | No |
| Zpacks Arc Blast 55L | 19.9 oz / 565g | Yes | Yes |
| Zpacks Arc Haul Ultra 60L | 19.6 oz / 556g | Yes | Yes |
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 19.6 oz, it’s significantly lighter weight than comparable backpacks even though it has a much more sophisticated and adjustable length frame system. While there is an initial learning curve to adjusting and fitting the Arc Haul Ultra, 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. It is a sweet backpack, but definitely pricey.
Disclosure: Zpacks donated a backpack for this review.
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Is the frame on the Ultra adjustable like the previous Arc Haul? I was under the impression that the curve was predetermined.
Nope – completely adjustable.
Hi Philip, I can see you are using a shoulder pocket on one of the straps but no water bottle pocket on the other. Why is that? What is your thought on carrying the water bottle up front in a water bottle pocket on one of the shoulder straps?
It’s just not my thing. I’m perfectly happy to keep my water bottle in the side pocket. What do I think out it? It just boils down to personal preference. There’s no right or wrong way.
Thanks Philip! Great piece; objective and thorough as usual. I note your comment suggesting about 30# max load, vs. Zpacks’ advertised 40# max. I am also trying to appreciate load carrying of new Haul Ultra compared to my aging 2017 Arc Blast, which has vertical carbon fiber stays, cylindrical rods about 3/16″ OD. That older Arc Blast is great for me up to almost 25 lb max. At >= 25lb, its rod stays bend like cooked spaghetti, side-to-side out of plane of back mesh between the webbing loop anchors, even with densest items packed on bottom. For me, the pack structure loses integrity for hip belt loading and carrying comfort. OK, a 25 lb comfortable max was good enough for the AT, with its frequent water and resupply sources. However, for 5+ day trips on western trails I sometimes want another 5+ lbs of more water and food and seek better load transfer to hip belt. My newer Hyperlight Southwest 3400 with internal aluminum frame carries great up to about 35#, but its back is not ventilated. Finally, my questions:
1. Are the curved (bowed) vertical stays of the Haul Ultra “flat bars” and do they have better side-to-side modulus (stiffness) than with older style cylindrical vertical rods in the Zpacks’ original Arc series?
2. What is the “width x thickness” (or diameter if round) of the vertical stays of the Haul Ultra, which look to be narrower than its horizontal bar stays?
(pictures and verbiage of Zpacks web are not clear for me on these design aspects)
1. They’re flat but they have some thickness (depth) to them so they’re not just flat. I think they do have better side-to-side stiffness, but I’ve seen so many variations, going all the way back to when they used arrow shafts, that I just can’t remember. I’d call and ask them.
2. Again – I will refer you to them. They can give you the precise dimensions.
“I’ve managed to wear out or destroy backpacks with every new ultralight backpack fabric that’s been introduced in the past 15 years…”
I’ve got a friend who worked for his father who was foreman of many major high rise construction jobs. Any time some tool salesman would tout the durability of their product, Dad would refer the tools to his son, who always managed to find a way to break the unbreakable while using them. Son says about himself, “I may not be the sharpest tool in the shed, but I’m certainly the hardest!” You’re in good company Philip!
My Arc Haul is the most comfortable pack I own because of its adjustability. I’m a relatively small female and it’s great to be able to microadjust the torso length. Also, the shape and padding on the shoulder straps are perfect. I really like the dual-pull on the hipbelt, which allows me to transfer weight to the hips better than any other pack I own (I own an embarrassing number of packs).
Personally, I don’t like curved packs (that’s why I can’t use Ospreys). So, I don’t arc my Arc Haul… I just leave the frame stays flat. The trampoline mesh still gives me some separation and ventilation even without an arc.
I’m a true Zpacks loyalist… I own their Arc Haul Zip, Duplex, Free Duo, classic sleeping bag 20 and 10 degree, and more accessories than I can remember. Great company to do business with.
I have the 70 liter version of this pack. Although there is no way to get rid of the arc (which affects what can be stored in the pack, and how), I have started storing my Gossamer Gear extra thin sleeping pad (folded up) in the space between the trampoline mesh and the back of the pack. It fits in there nicely and does not fall out. While this eliminates the ventilation feature of the pack (which I don’t care about), it allows some of the weight of the pack to press directly against your back, which I prefer. Yes, it is strange to buy an arc pack but not like the arc, but this approach works for me. Great pack, with this hack.
I have the “classic” Arc Haul. Can you comfortably push the Ultra 70L version to carry 35, even 40 lbs – base, food, water?
I sincerely doubt it. The only thing that’s different is the size of the bag. The frame and hip belt are identical.
Shannon, reviews say the frame arc is not adjustable. How do you have it flat?
I’m considering the pack if they CAN be flat.
Thx
The curvature on older models was adjustable. I think in this case she’s talking about the torso length which is adjustable. The curvature on the current model is not flat and it is not adjustable.
I noticed that you have the gray which is the ultra 100. I haven’t seen any reviews on that. Now that you’ve had it few months, would you recommend going that route, or just getting the ultra 200 black?
I haven’t had any abrasion issues with the Ultra 100 fabric and I’ve used that pack quite heavily. But if 200 is available, get that. Can’t hurt. I love this pack – fits me great and the ventilation is very comfortable.
Thanks for this review. I’ve wanted to try a ZPacks pack but haven’t yet jumped in. I do dig my HMG 3400 (junction..black fabric) for doing just-about-anything kinda camping, but looking for something that might suit for a more-specialized set of trips starting with a desire to do the JMT next year (I’ve sectioned all of it and done a fair bit in the surrounds). With my HMG pack at ~34 oz, this looks like a great way to drop 12-14 oz (depending on where the actual weight comes in for the Arc Haul) with an (also) US-made pack and still have a frame and room for a decent-sized bear canister (using a Berikade Blazer at the moment which is 12″ x 9″). Sounds as if the pack is likely to fit well given the adjustability…and I’ve been quite pleased with the only significant piece of gear I have from ZPacks at the moment, the Duplex. I suspect I’d end up bumping up to the 70L for the same reason I did a 3400 in the HMG…small weight penalty for the added volume. Sound like a good approach?
sounds good.
Hi Phillip, I want to mention I’m a huge fan of your gear reviews. I usually research most every piece of gear I purchase, but always visit Section Hiker last before making my decision. Most of my equipment is from Zpacks, with my favorite backpack being the 55L Arc Blast. My question is, the Arc Haul Ultra 50L worth gaining 9 ounces and losing 5 liters?
ps: I see you were carrying the Inreach Mini, because of you I stuck with my Inreach Explorer+ Now I don’t know what to do! lol
If you like the Blast, I’d just keep that. That’s a mini2, actually. They improved the interface, came out with a better app, and increased the size of the battery. It’s also lighter. I still kept my Explorer+ though. I wouldn’t bother upgrading as long as you enjoy using the Explorer+.
Thanks for the thorough review, it’s much appreciated. You mentioned that the pack is a little noisy “The downside is that the pack makes a little noise when hiking as the parts rub together.” could you please elaborate on this a little? Is it only under certain conditions or all the time? How loud/annoying is it?
I’m currently using an Exped Lighting 60 (1160 gm / 41oz), it’s a great pack but is wearing out. Occasionally it squeaks a little (perhaps becasue it’s getting old?) and then stops. I’m not sure I’d want a pack that was constantly squeaking. Any insight that you can provide will be greatly appreciated.
I used the pack all summer and autumn after that so I guess I just blocked out any noises. I don’t remember it being a problem.
I bought one and took it for a 25 km test run. No noise that I could detect, so I’m very happy. Thanks for the informative review.
My joints make enough noises to drown out any pack or sleeping pad.
I used my arc haul several years now, and the noise is more like when you’re in the saddle on a horse, actually pleasant to me, of course not as loud. It’s definitely not loud enough to announce your presence.
About the swagger on the frame bars or as I think A. Wonder is talking about saying, “ side-to-side out of plane of back mesh between the webbing loop anchors”. My arc haul bars definitely are out of alignment with the mesh, and haven’t figured out what to do with that yet. Maybe have my pack too crammed full volumetrically though rarely over 28 lbs loaded weight wise. Nevertheless it still works and gets the job done, and wouldn’t trade it, though can’t imagine going as small as a 60 or 55L pack, oh yeah I know it’s done or they wouldn’t offer them.
Hi Phillip, I have the Arc Haul Ultra 70, love the hip belt, large single bag and the material being waterproof for where I live, but having several issues with the shoulder straps. On my first hike the lock buckle where the thin strap from the bottom of the back to the padded shoulder strap tore off at the shoulder strap end (where it is attached to the daisy chain material, which is weaker and the stitching is right under the buckle at the most stressed point). They replaced the pack, but the straps on the new one (which are kind of a plasticy material) keep slipping through the lock buckle and i need to continually tighten them. They keep slipping until the strap runs entirely through the buckle, so its not as if i have it too tight or in one wrong angle / spot. Anyone else have this issue ?
Hi Phillip,
I just started looking at this pack and am very interested, thanks to your review.
You mention that it’s not hydration compatible: “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.”
The picture on the Zpacks website shows a hose running from…somewhere. Not trying to play gotcha, but do you have any thoughts about how a hydration bladder/hose might be rigged? I really prefer a hydration bladder to a bottle when on the trail, although not necessarily in camp.
Link to the picture: https://zpacks.com/products/arc-haul-ultra-60l-backpack#images-15
Tom
From the product description at Zpacks.
“A drinking tube can be threaded out the corner of the roll top closure and secured with the daisy chain on the shoulder strap.”
Just add – I adore this pack. It’s my #1 choice at the moment and what I use when I’m not working.
Not sure if this review is still taking questions/comments…but: don’t the Gregory and Osprey measure the volume of the main bag only, and Zpacks and MLD include the volume of the side pockets, etc…So that the Gregory and Osprey bags actually have quite a bit more volume. Or, am I wrong about that?
Actually – they Gregory and Osprey only measure closed pockets. Zpacks and MLD measure all pockets open and closed.