Arc'teryx Gamma LW Pant
The Arc'teryx Gamma LW Pant (formerly Gamma SL) is best suited for lightweight softshell summer alpine activities and warm-weather hiking in temperatures of 45-70°F. At 8.4 ounces in size medium, it uses Fortius 1.0 softshell fabric made from 43% recycled nylon with four-way stretch and a light DWR treatment. Best for technical climbing, scrambling, and fast-moving mountain pursuits where breathability and mobility matter more than weather protection. Not suitable for cold conditions or sustained rain. Key features include gusseted crotch, articulated knees, zippered pockets, and cinchable cuffs.
Is the Arc'teryx Gamma LW Pant Good for Hiking?
Yes, particularly for summer alpine hiking where you're moving fast and need breathability. The Fortius 1.0 softshell stretches in four directions, which means no resistance when high-stepping over obstacles or making wide stem moves on scrambles.
The fabric weight sits perfectly between lightweight trail pants like the Incendo Pant and heavier softshells. At 8.4 ounces, it's light enough to wear comfortably in temps up to 70°F without overheating, but substantial enough to provide abrasion resistance on exposed granite or basalt.
The gusseted crotch adds range of motion without creating excess fabric. Combined with articulated knees that bend naturally, these pants move better than straight-cut hiking pants. The cinchable cuffs keep debris out of your boots during talus scrambles or dusty trail sections.
For cold-weather hiking below 45°F, you'll want the standard Gamma Pant instead. The LW version prioritizes breathability over insulation, so it won't keep you warm when temperatures drop.
Does the Arc'teryx Gamma LW Pant Work for Climbing?
Absolutely. This is where the pants excel. The four-way stretch fabric moves with you on technical routes without binding or restricting motion. Whether you're reaching for a high hold or making a long stem move, the material gives without feeling loose.
All pockets have zippers, which matters when you're upside down on an overhang or hanging from a belay. The thigh pocket fits a phone securely, and the hand pockets work for quick items like chalk or energy gels. No rear pockets means nothing digs into your back when wearing a harness.
The low-profile waist adjuster sits comfortably under a climbing harness without creating pressure points. Unlike panty belt systems, the in-pants design stays flat and doesn't interfere with harness fit or movement.
Wind resistance is moderate. The DWR treatment sheds light moisture, but sustained wind will cut through eventually.
Slimmer Cut with Three Inseam Options
The LW version runs slightly slimmer through the legs with a more athletic cut. At 6 feet and 165 pounds, I wear a 32 Regular and find the fit trim without being restrictive. The straight-leg design looks cleaner than baggy technical pants while still maintaining full mobility.
Arc'teryx offers three inseam lengths: Short (30"), Regular (32"), and Tall (34"). This beats most hiking pants that only come in one length. The adjustable cuffs help dial in the fit further, letting you cinch them above your boots or leave them loose depending on conditions.
The waistband sits slightly lower than the standard Gamma, which some climbers prefer for harness compatibility. A soft fabric liner on the interior waistband reduces abrasion when wearing a pack hipbelt or harness for extended periods.
Sizing runs true to Arc'teryx standards, which means slimmer than brands like Patagonia or Outdoor Research. If you're between sizes or prefer a relaxed fit, size up. Check current sizing at Arc'teryx's website.
Gamma LW vs. Standard Gamma Pant
Weight is the obvious difference. The LW weighs 8.4 ounces, compared to 12.5 ounces for the standard Gamma. That 4-ounce difference comes from the thinner Fortius 1.0 fabric compared to the Fortius DW 2.0, which means better breathability but less weather resistance. The standard Gamma blocks wind more effectively and provides warmer insulation for shoulder-season use. The LW breathes better during high-output activities but offers minimal warmth when stationary.
Both pants use similar construction: gusseted crotch, articulated knees, zippered pockets, and adjustable cuffs. The feature set remains consistent across the Gamma line. The main choice is whether you prioritize breathability (LW) or weather protection (standard).
For comparison, the Outdoor Research Ferrosi splits the difference at 10 ounces with slightly better breathability than the standard Gamma but more weather protection than the LW.
Temperature Range and Breathability
The Gamma LW Pant handles 45-70°F comfortably during active use. Below 45°F, you'll want to wear base layers or switch to warmer pants. Above 70°F, lighter options like the Gamma LW Shorts make more sense in real heat.
Breathability is the LW's strongest feature. The Fortius 1.0 softshell allows greater airflow than heavier softshells. I stayed comfortable even when working hard in 60°F temps with full sun exposure.
The pants dry fast after getting wet from creek crossings or morning dew. Not as quick as synthetic hiking pants, but faster than cotton or heavy softshells. Plan on 2-3 hours of active wear to fully dry in moderate conditions.
Durability and Abrasion Resistance
The Fortius 1.0 fabric resists abrasion better than most hiking pants despite its lighter weight. After a season on granite scrambles and basalt ridges, mine shows minimal wear beyond some sun fading.
The knees and seat show no visible abrasion despite regular use on rough rock. Cuffs hold up well to constant boot contact. Laminated cuffs prevent fraying at the hem, a common failure point on softshell pants.
The DWR treatment fades over time. After about 40 days of use, water no longer beaded as effectively. Retreating with Nikwax restores performance. Wash in cold water, line-dry, and the pants maintain their shape.
When to Choose the Gamma LW Pant
Buy these if you need lightweight softshell pants for summer alpine climbing, fast-moving mountain objectives, or warm-weather hiking where breathability matters more than weather protection. They work great paired with a lightweight shell jacket when conditions shift.
Skip them if you primarily hike in cold conditions below 45°F or need maximum weather resistance. The standard Gamma Pant or Palisade Pant makes more sense for shoulder seasons and variable weather.
The Gamma LW Pant fills a specific niche: technical mountain pants for warm conditions that require durability and stretch without excess weight or warmth. For that use case, they're hard to beat.
