Arc'teryx is known for impeccably high-quality gear, from harnesses to backpacks to clothing. This pack is not one of their shining performances, however. The Alpha AR 55 is designed to be an "All Round" (AR) backpack, and it certainly will function for any of the mountain sports, from skiing to rock, ice, and alpine climbing. But it is just a little below average in performance for all of them. It is more well suited to lighter, bulky loads which fill the pack and give it more structure, so if this is your typical mode in the mountains, this may still be a worthy companion.Editor's Note: This review was updated on October 28, 2022 with information on the revised version of the Alpha AR 55 pack.
Arc'teryx Alpha AR 55 Review
Cons: Bulky, sloppy suspension, less comfortable, wonky (if durable) buckles
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Arc'teryx Alpha AR 55
$250.00 at Amazon
$195.00 at REI
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|$110 List||$144.00 at Backcountry|
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|Pros||Durable, light for the volume||Comfortable, affordable, durable, fully featured||Versatile, simple, durable, well-priced||Lightweight, simple, excellent pack for steep, technical terrain||Durable, comfortable, optimized for ski mountaineering|
|Cons||Bulky, sloppy suspension, less comfortable, wonky (if durable) buckles||Not as lightweight as some packs||Less features, some wonky strap designs||Less durable, less versatile, no side straps||Heavier, novel front access zipper can be difficult to use|
|Bottom Line||Though lightweight and durable, we are disappointed by the carrying comfort of this pack and find the buckles to be difficult to manipulate||This is an excellent pack for most mountaineering uses, excelling in comfort and versatility in all alpine terrain||This is a pack-of-all-trades well suited to a variety of mountaineering pursuits||This is an excellent on-route climbing pack for challenging steep terrain in the mountains||The durability and feature set of this pack make it particularly well suited to ski mountaineering|
|Rating Categories||Arc'teryx Alpha AR 55||Osprey Mutant 38||Black Diamond Speed 40||Black Diamond Blitz...||Ortovox Peak Light 32L|
|Weight to Volume Ratio (20%)|
|Specs||Arc'teryx Alpha AR 55||Osprey Mutant 38||Black Diamond Speed 40||Black Diamond Blitz...||Ortovox Peak Light 32L|
|Measured Volume (liters)||50||37||45||29||30|
|Measured Weight (pounds)||2.93||2.84 (without lid), 3.25 (with lid)||2.93||1.09||2.53|
|Measured Weight (grams)||1330||1288.2||1330||496.1||1148.2|
|Weight to Volume Ratio (grams per liter)||26.60||34.82||29.56||17.11||38.27|
|Frame Type||Internal Frame, removable framesheet and back panel||Inner framesheet with aluminum stays||Removable foam and plastic framesheet with 3 stays||Foam pad||Swiss Wooltec knit back construction|
|Fabric||N315r-LCP nylon||210D nylon with 420HD nylon packcloth on bottom||210d ripstop main, 420d abrasion||Dynex ripstop||Nylon 420D Oxford|
|Pockets||1 main, 2 zippered lid, 1 zippered internal, 1 side, 1 side access zipper||1 zippered lid||1 main, 2 zippered lid, 1 internal hydration||1 main compartment, 1 waterproof top lid, 1 internal zippered||1 lid with 2 compartments, 1 hip belt pocket|
|Hip Belt?||Yes - not removable||Yes - reverse wrap hybrid EVA foam w/ gear loops and ice clipper holsters||Yes - padding removable, not belt||Yes - removable webbing belt||Yes - removable hip belt|
|Removable Suspension Padding?||Yes||Removable framesheet and/or dual stays||Yes||Yes||Yes|
|Lid?||Yes - removable||Yes - removable with stowable FlapJacket for lidless use||Yes - removable||Yes - removable||Yes|
|Hydration System Compatible?||Yes||Yes - internal pouch with buckled hanging loop||Yes||Yes||Yes|
Our Analysis and Test Results
Since we tested the Alpha AR 55, Arc'teryx has released a revised version. The material and many features remain the same, but the brain's zipper pocket has been moved closer to the back side of the pack, and the ice tool securement system at the bottom has been tweaked to be more low profile. The hip belt suspension also appears to have been updated, which addresses some gripes we had regarding comfort and suspension in our testing. However, as we've yet to test the new pack, be aware that our review text below still pertains to the previous model. The two packs can be compared above, with the old Alpha AR 55 on the left and the updated version on the right.
Arc'teryx has had some of our favorite mountaineering products for many years, from clothing to packs to harnesses. This pack misses top marks in this review for a few surprising reasons.
AR stands for "all round" in Arc'teryx product lineups. This is another "pack-of-all-trades" kind of mountaineering pack. This can be a good thing, but it can also be a fault. In the case of the Alpha AR 55, we weren't quite charmed. It was below average in many of our metrics and field tests — not extremely so, but just enough so to leave us disappointed. Admittedly, we have such high expectations of Arc'teryx that this also contributed to our disappointment.
This pack is certainly versatile enough to take on your next mountaineering trip, day trips and overnights included, and you will find it adequate no matter your travel method of choice. It is a relatively simple pack. The main limitation for versatility, however, is the size and the way it carries. We did not like it as much for skiing, for example, due to the girth and stability issues with the suspension. And it is a great size for general mountaineering, but feels a bit too bulky for technical movements in an alpine environment. It has all the components for ice climbing as well, but it feels bulky to climb with, and the hook-and-loop style buckles are difficult to operate with bare hands, let alone while wearing gloves.
Weight to Volume Ratio
In our volume test, we measured closer to 50 liters of usable space in this pack, but we did not count the brain or side pocket volume, and there is no real industry standard on reporting volume — so our test is consistent across all packs in just measuring the volume of the main compartment.
The materials used, combined with the simple and weight-saving design, mean this pack is reasonably light for the 50+ liters of space it provides.
The Alpha AR 55 lost quite a few possible points for comfort. In mountaineering packs, this is a nuanced and very important metric — we need something that can handle a dense load while also allowing for a variety of complex movements, all without impacting our center of gravity too much.
The AR 55 has a bit more girth than our favorites in this category — that is to say, the cylinder of the main pack is more squat, and our favorite designs tend to be slightly narrower, which reduces the amount the pack can impact your center of gravity.
The other issue was with the suspension. The hip belt is sewn onto the pack, and there is a floating triangle of foam sewn in between the two sides of the hip belt. Above this, there is no foam in the back panel other than the full-length removable foam pad and plastic framesheet (with a single vertical stay--we also typically prefer packs with two stays). This allows the pack material to slump a little against the removable framesheet and can put undue pressure on your lower back or just feel sloppy and insecure.
Arc'teryx certainly still hit the mark for durability with the AR 55. The material is rugged, and the design is one of a sturdy workhorse. The buckles, which we will discuss more in the Features metric, were not a feature we liked, but they are certainly durable. If buckles tend to be the weak link in your experiences with mountaineering packs, this could be a good solution for you.
There were several features we really liked on this pack, including the full-length side zipper and the front bungee system. The large, expandable pocket on the opposite side of the zipper may be something people like as it can accommodate a water bottle or wands or a picket, but we found it to be a bit too much and prefer our mountaineering packs to have a more svelte and smooth exterior to reduce snagging in technical terrain. But we really liked the front-facing zipper on the lid!
The sewn hip belt was a structural disappointment, and some may not like that you can't remove it for your summit bid. The main disappointment in this metric is the buckles. They use a hook-and-loop style which is purported to be more durable, and we are quite sure it is. This comes at a significant cost to accessibility, however. The cord was difficult to line up and set into the hook and often required us to remove our gloves to thread it into place. We tried to figure out a method where we could just tug the two pieces together, but the geometry is off, and the loop often wouldn't set in place and would instead pop apart in our hands. Bummer. A similar system is used to attach the heads of the ice axes and felt similarly fiddly. If durability is your primary concern with buckles, this issue may actually be a major strength, and if so, give it a go! Otherwise, try these buckles out a few times at a shop before purchasing this pack.
Arc'teryx is not known to be a budget brand and certainly confirms the old adage "you get what you pay for." They deliver consistently remarkable products. The Alpha AR 55, however, is not their best. There are a few drawbacks and frustrating features. However, if you've read them through and don't think they'll be an issue for you, then this is definitely a good value. This is a highly durable pack that will last a long time, and if the fit doesn't interfere with performance or balance for you, we think you'll be psyched on it.
We were really excited to get our hands on the Alpha AR 55 for this review update. We have loved so many packs from Arc'teryx, as well as many other products like harnesses and clothing. However, this pack was not our favorite due to some fit issues and some function problems with the features. We hope to see an update to this pack as it is a brand that we trust, and the 50-liter size range of packs offered across the industry continues to leave us generally disappointed.
— Lyra Pierotti
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