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Arc'teryx Beta SL Pant - Women's Review

Pushes the boundaries of our expectations.
Top Pick Award
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Price:  $275 List | $206.19 at REI
Compare prices at 3 resellers
Pros:  Durable, light, comfortable, excellent range of motion
Cons:  Expensive, can’t fit over boots
Manufacturer:   Arc'teryx
By Lyra Pierotti ⋅ Review Editor  ⋅  Jul 17, 2019
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#4 of 9
  • Water Resistance - 25% 9
  • Comfort and Mobility - 20% 8
  • Breathability & Venting - 20% 7
  • Weight - 15% 8
  • Packed Size - 10% 9
  • Features - 5% 5
  • Durability - 5% 9

Our Verdict

Arc'teryx holds up its impeccable reputation with the Beta SL rain pant. These pants won our Top Pick Award for mobility and versatility. They were so comfortable we could make technical ice climbing moves with ease when wearing them. The side zippers only reach halfway up the pants, making it difficult to get them over most mountaineering boots, but once they're on, they perform as well as most lightweight hardshell pants. These rain pants push the limits of what we can do in lightweight rain pants, but remain light enough that they make an excellent emergency shell for lightweight hiking trips.

Updated Version Available

The Beta SL pant has been significantly updated since our testing period. Read on to learn more about these changes.

July 2019

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Our Analysis and Test Results

The Latest Version of the Beta SL

Arc'teryx has made significant changes to these rain pants, including amendments to the overall design, choices of fabric, and most obviously, full-length leg zippers instead of the 1/4 zip of the previous version. Below is a quick outline of some new features.
  • Zippers changed --Quarter-length side zippers have been updated to zippers that run the length of the pant.
  • Updated waistband — Integrated, adjustable belt added.
  • Updated materials --Updated materials used in construction, N150p-X GORE-TEX fabric with Paclite Plus technology.
  • Price increase --A steep price increase accompanies the updates, from $200 to $275.

We link to the new Beta SL, but as we've yet to get our hands on the latest version of these pants, the following review refers to the previous model.

Hands-On Review of the Beta SL

The Arc'teryx Beta SL are designed as an emergency weatherproof pant—light enough to justify carrying it on any adventure in case the weather changes unexpectedly. In our tests, we found it to be even more versatile than advertised. Our favorite use for these pants was hiking and, surprisingly, ice climbing. We loved how lightweight these pants were—we often kept them in our ice climbing backpack. We had to take our boots off to slip the pants on, but as an emergency shell pant, this still worked for us. This meant we could add little weight to our pack, and if we arrived at our ice climb to find the obvious line was under some dripping water, we could put these on and climb on. Sweet, and well worth the six ounces.

We could even go ice climbing in the Beta SL.
We could even go ice climbing in the Beta SL.

Water Resistance

The Paclite material from Gore-Tex is a tough, waterproof shell material with taped seams. The pores of this fabric are smaller than a droplet of water, so mechanically, it just can't get through—unless you sweat, and get wet from within (see Breathability & Venting, below).

In our tests, we found these to be among the best in the review. We stuck our legs under dripping waterfall ice climbs and watched the water roll right off.

The Gore-Tex Paclite  up close.
The Gore-Tex Paclite, up close.

But in the modern world, most waterproof fabrics are roughly on par regarding their ability to keep water out—with rare exception. As such, we looked at other features which affected waterproofness. In the simplest terms: are there other ways water can get us wet when wearing these pants? The simplicity of the Beta SL ensured that water stayed outside. The side zippers are waterproof and only go halfway up the leg. This means they cannot be vented and may not slip on over your bigger boots, but they reduce weight and the opportunity for water to get through the fabric. There are no pockets, as well, which is one less hole to cover or seal with a waterproof zipper.

The waistband is elastic with a simple shoelace style adjustable drawcord. We liked the OR Aspire pants waist design better, with the grippy waistband, but the adjustability of the Beta pants ensured we could slip these on easily over our hips and cinch them tight to keep them up.

The cuffs were well designed: smooth and adjustable with a metal hook to attach to your shoelaces.
The cuffs were well designed: smooth and adjustable with a metal hook to attach to your shoelaces.

The cuffs also have a metal shoelace hook, similar to a gaiter, which helps keep the pants low over your shoes, and an adjustable elastic drawcord to close the cuff around your boots. If your shoes are waterproof, this provides an excellent seal against the elements and makes it reasonable to post hole through the snow in these pants.

Comfort & Mobility

The Beta SL was our favorite lightweight ice climbing or technical shell pant.

We were able to put these on over our comfortable soft shell climbing pants when we got to our ice climb and discovered that it was dripping with water right where the climbing was best—the shape of these pants allowed the best mobility and range of motion in this review. In fact, between the excellent shape and ultra light weight of the fabric, we could hardly tell we had put on a shell pant over our climbing pants. Impeccable design.

Wardrobe change: from skiing to ice climbing in the Beta SL.
Wardrobe change: from skiing to ice climbing in the Beta SL.

We could climb, ski tour, and hike comfortably in these pants. They stayed securely over our boots with the drawcord and gaiter-style shoelace hook, which allowed us to move quickly and fluidly through the mountains without worrying about whether or not our pants would remain securely sealed against the elements.

Breathability & Venting

The Gore-Tex Paclite material is among our favorite waterproof/breathable fabric. This is a lighter product from Gore-Tex, and as such, we find it to be more breathable than thicker waterproof materials. This makes sense, as breathability essentially depends on the ability of your body to pump heat through the membrane—a thinner membrane feels much more breathable in our tests. This can come at a cost to durability, but we often find that it is well worth it—except if you're looking for pants for hard labor like working on cars or a farm.

These pants fell behind the OR Aspire in this category, however. The two pants are made of the same Paclite material, but different face fabrics—and the Beta SL has no venting. It became clear to us that these pants are likely products of their home ranges: OR is from the Pacific Northwest, a humid and relatively mild climate where venting becomes a necessity because it can be hard to pump moisture from a humid environment (inside the pants) to another humid environment (outside the pants). Arc'teryx is optimized for colder, drier climates, where it is easier to pump water vapor from inside the pants to the drier air outside.


The Beta SL weighs an impressive six ounces for a small pair of pants. It is a highly streamlined pant designed as an emergency storm proof layer.

This makes it easy to justify packing it in nearly every pack you might carry—just in case. The pants don't have many convenience features, which helps keep them light. For example, there are no pockets, and they have somewhat shorter 1/2 length side zippers which make it harder to get them over bigger boots. These are optimized for hiking, but still might find their way into your summer mountaineering kit, or you might just put them on at the trailhead for a ski tour when the weather is a bit wetter or stormier.

The Beta SL didn't have a stow pocket  but packed down really small.
The Beta SL didn't have a stow pocket, but packed down really small.

Packed Size

These pants pack down small, but they don't pack into a pocket—because they have no pockets. We didn't penalize these pants much for this, however, because we don't typically need a small package with a clippable loop to clip pants to our harness when climbing. We like this feature for down jackets, hard shell jackets, and wind shirts, but we don't find it as useful for pants. If the weather turns, we're usually going to rappel or descend, so we will throw on a shell jacket and flee to shelter, then we can usually dig out shell pants from our pack if need be.

However, a packable pouch can provide good protection for the fabric of the pants, which might be useful when packing the pants among objects like crampons, carabiners, stoves, etc. that could snag or rip the pants when pulling them out of your backpack. On the flip side, pants are easier to stuff into your climbing pack because you can stuff one leg down one side of the pack, and cram the other leg in another infinitesimally small space. In the end, we thought the lack of pockets and a stowing option or clippable loop was not a big deal.


The Beta SL is light on features—but optimized with thoughtful design features that keep it light weight and improve its versatility.

For cold weather use, we liked the smooth panel on the inside of the ankles. It is similar in design to crampon panels, which protect pants from knicking or holes when wearing crampons; however, it is not made of more rugged material. Additionally, the adjustable elastic drawcord in the cuffs also helps keep the fabric in and reduce chances of snagging.

The Beta SL even fits over our ski boots.
The Beta SL even fits over our ski boots.

The waist is a simple design, elastic with a shoelace style adjustable drawcord, keeping it light and easy to slip on and secure over your hips. The limited features, however, may reduce the versatility of these pants. But if you don't need the features they're missing—like full side zips, one of our favorite features—then you'll be super psyched on these pants.


The Beta SL gets a perfect 10 for durability in this review. This is hard to achieve in lightweight pants, but we were so impressed by the cuff design, a panel that mimics a crampon patch without using thicker material, that we thought it deserved top durability marks. We took these pants ice climbing around sharp ice tools and crampons and stuffed them into our mountaineering and ski touring backpacks. They held up impressively well through months of testing.


Arc'teryx is never known to make cheap gear. But it is often, impressively, well worth the money. These are not as versatile as our Editors' Choice winner, the *OR Aspire*, but if they fit your needs, you will get a lot of wuse out of them, and find them very useful.


The Arc'teryx Beta SL is a thoughtfully designed, phenomenal shell pant. It is light enough to be a great rain pant for hiking and burly enough to fill the niche of a lightweight hardshell pant. While they may not be the most affordable storm proof pant, they are still a surprisingly good value: durability, thoughtful design, and climbing comfort combine to create a fantastic bad weather pant.

We couldn't quite fit mountaineering boots through the Beta SL without taking the boots off.
We couldn't quite fit mountaineering boots through the Beta SL without taking the boots off.

Lyra Pierotti