Arc'teryx Alpha SL Anorak Review

For multiple years, the Arc'teryx Alpha FL was the top-rated jacket in this review. Recently that jacket has been removed from the Arc'teryx line up and we are unsure when or if that excellent product will return. The Arc'teryx Alpha SL Anorak may look similar, but it's a substantially more lightweight shell which is great for ultralight applications. However, don't expect the same outstanding all-around performance as with the old Alpha FL.

Performance Comparison

Weather Protection

When it comes to weather protection, the Arc'teryx Alpha SL Anorak offers only modest performance. As an ultralight hardshell, it has an especially slim cut to maximize weight savings. Some of our testers were disappointed with the high waist hem and short arm sleeves because they seemed to ride up. This was particularly a problem while climbing because repeatedly raising arms overhead often caused this jacket to come untucked from a climbing harness. We would gladly accept an extra ounce of fabric for a lower waistline that would avoid this issue.

Despite some complaints about the waist and sleeves, we were impressed with the weather protection from the 3-layer Gore-Tex Hadron fabric. We were astounded that this ultralight material continued to bead water after months of testing while also resisting cuts and abrasion from sharp ice climbing gear and coarse rock. The main zipper on this pullover also proved to be completely waterproof and the simple hood fit well with or without a helmet on underneath.

Weight

The most impressive aspect of the Arc'teryx Alpha SL Anorak is its astonishing low weight. At 7.6 ounces for a size large, it was easily the lightest hardshell jacket in this category. Although some other companies do sell jackets that are comparably ultralight, we have never come across another jacket in this weight class that offers close to the same level of weather protection or durability. In fact, we would classify all other sub-10 ounce models as rain jackets rather than proper hardshells. The Alpha SL Anorak is simply the lightest jacket that we believe is suitable for winter climbing.

To enjoy the weight savings, however, you do have to accept considerable compromises. We were happy to climb and ski occasionally in the Alpha SL Anorak but we wouldn't want to use it every day. The Alpha SL Anorak is a great choice for serious human-powered endeavors when ounces really matter but is less ideal for winter activities close to the trailhead. As such, we consider this to be a luxury piece of gear for niche ultralight applications. However, most people will also want a second hardshell more casual skiing or ice climbing days.

Mobility and Fit

We were somewhat disappointed with the fit and mobility of the Arc'teryx Alpha SL Anorak. The waist hemline felt high and the sleeves were a little short. The Gore-Tex Hadron fabric also is not as stretchy as the materials used on some other hardshells. As a result, we noticed the waist and sleeves riding up during dynamic movements.

When it comes to sizing, we found this jacket to be slightly smaller compared to other Arc'teryx jackets. Online customer reviews echoed this observation. If you're in between sizing we recommend sizing up (eg. if you're between a medium and a large, choose a large). However, if standard sizes usually fit, you will probably be most happy selecting the same size.

Venting and Breathability

The ultralight aspect of the Alpha SL Anorak demands that it make some serious sacrifices. Many of the sacrifices come in the form of limited venting possibilities. Its pullover design significantly reduces your ability to vent heat out the main zipper. It also lacks pit zips for shedding heat during a prolonged cardio effort.

On the other hand, we were impressed with the breathability of the Gore-Tex Hadron fabric. This lightweight material seemed to breathe better than the thicker materials used on many other hardshells. Still, the breathability of waterproof fabric is rarely enough to avoid sweating out the inside of a jacket during sustained exertion. Due to this reality and the limited venting possibilities of this jacket, it's best to think of this model as something to take off during an uphill approach and then put on before you start the technical climbing or ski descent.

Features and Design

This isn't a jacket you should buy for its feature set. Instead, it's a jacket you should buy for its simplicity and the weight savings that go along with that. In terms of features, the Alpha SL AnoraK has very few. It only includes a single pocket that's located on the left breast. This small zippered pocket is big enough to hold a phone but not much else. However, the absence of any hand pockets leaves the waist smooth which can reduce any points of irritation below a backpack hip belt or climbing harness.

Beyond the single pocket, the other features are sparse. The hood includes just a single drawcord and the chin does not incorporate any soft fabric swatches to reduce chafing. If you're forced to wear this jacket fully zipped with the hood up for a long period of time, expect to feel uncomfortable. The wrist closures utilize a simple velcro mechanism. We found this capable of keeping the cuffs reliably closed but the short length of the sleeves left them riding up occasionally.

Value

Anyone searching for a bargain on a hardshell to get them through the winter should probably consider another model. The Arc'teryx Alpha SL Anorak is simply too much of a specialty piece to meet the needs of most hardshell shoppers. Even though its price tag might be tempting compared to most other hardshells, it would be a poor choice for an everyday jacket. However, if you already own a sturdy hardshell and are looking for a second lightweight jacket to bring along for the biggest uphill days, then the Alpha SL Anorak is an excellent choice. Among specialty ultralight jackets, we consider it to be a solid value.

Conclusion