Black Diamond Alpine Light Pants Review

Any climbing pant worth its salt has to hold up to a world of torment—and the Black Diamond Alpine Light Pants rise to the task. I've tested an obscene amount of technical climbing apparel and have pretty strict guidelines for what makes a solid pair of slacks. I didn't label these the best climbing pants on the market for 2025 lightly. The Alpine Light Pants have accompanied me on countless adventures in the years I've had them, from crumbly baboon-infested cliffs in East Africa to full-on alpine traverses in Wyoming's rugged Wind River Range. I've clocked easily over 100 pitches of climbing in them, and they keep on ticking. What's the secret sauce? Check out my deep-dive review below, or see how it stacks up to the rest of the competition in our article on the best men's climbing pants.
 

Table of Contents

• Performance
• Materials and Durability
• Weight and Packed Size
• Breathability and Ventilation
• Features
• Fit and Mobility
• What We Like/What We Don't
• Comparison Table
• The Competition

Performance

In the diverse world of climbing, it's rare that a pair of pants ticks all (or most) of the boxes for vertical pursuits. For everything but high-altitude mountaineering, where chunky soft or hardshell pants are required, the Black Diamond Alpine Light Pants are my favorite rock-wrangling companions. They strike a stellar middle ground in terms of fit—not too baggy, not too loose—and have just the right amount of features without adding bulk. At 10.2 ounces, they won't be the reason you don't send your project, and they have a light, breezy feel despite top-shelf durability. All told, these are some of the most versatile technical pants I own. Below, I'll go into some of the standout specs of these pants, how they stack up with the competition, and the (very) few areas I think they could be improved.
 

Materials and Durability

For me, the material makeup of climbing pants is a key consideration. The Alpine Light falls in the middle of the durability spectrum—light and airy enough for ultralight sport and alpine climbs, but stalwart enough for chimney squeezes and rugged scrambles. While they aren't my go-to pick for bouldering, they are popular amongst pebble-wrestlers and multipitch enthusiasts alike. They aren't necessarily the most flashy design out there, but simply get the job done. The secret sauce, for me, lies in the 85% nylon, 15% elastane single-weave, four-way stretch fabric. The material has adequate next-to-skin comfort and wicks moisture smoothly, with a DWR finish for thwarting light moisture. I had my durability doubts when first sliding them on, but these pants have blown me away. I've put them through the wringer, most recently wearing them on a multi-day climb of the Cirque of the Towers Traverse in Wyoming's rugged Wind River Range and big wall climbs in Zion National Park with great results.
 

On the Cirque Traverse, I found myself squeezing through endless sharp granite chimneys, scrambling up gnarly 4th-class gullies, and just generally abusing the heck out of the sturdy Alpine Light. These slacks crossed the finish line with zero issues or tears to speak of and even fended off a freak flurry of snow midway up the daunting final pitches of the Shark's Nose. The Cirque—and many other zones I've climbed in with these pants—required a long approach and miles of trekking/scrambling mid-climb. The soft fabric walks well and manages moisture like a champ. You don't have to worry about chafing while clocking serious mileage in the backcountry, and the cut is reminiscent of our favorite hiking pants, such as the Outdoor Research Ferrosi and Patagonia Quandary Pants (I'd say it's closer in fit to the Quandary). In short, the Alpine Lights nail a nearly perfect balance of weight, durability, and moisture management in the fabric, making them versatile trousers for all manner of mountain adventures.
 

Weight and Packed Size

Tipping the scales at 10.2 ounces, the Black Diamond Alpine Light Pants don't win any ultralight awards—but that's not what they are billed for. Rather, they hit a happy medium between airy, featherlight climbing pants (such as our favorite ventilated pants, the 8.1-ounce Himali Equilibrium Stretch Pants) and burlier softshell alpine models (such as the popular 13.4 oz. Arc'teryx Gamma Pants). The Alpine Light packs down small—about the size of a Nalgene—and therefore takes up minimal space in a climbing pack. The light fabric is surprisingly durable given how packable and breathable it is, making these pants great for long climbs and traverses over rough terrain where speed and efficiency are key.
 

Breathability and Ventilation

Whether you're sweating through your shirt on blistering desert splitters or huddling in a shiver bivey on the side of a snowy peak, breathable, ventilated climbing pants are key for all-day comfort on the rock. While light, airy fabrics are a boon for climbs in hot climates, you want your pants to manage sweat buildup in cold conditions as well. Cotton-blends produce comfortable fabrics for light climbing with short approaches (such as the 97% cotton, 3% elastane material on the cozy La Sportiva Roots Pants), but cotton isn't as durable, lightweight, or breathable as synthetic materials and isn't a great choice for long, full-on missions. Though there aren't dedicated venting pockets on the pants, the fabric is inherently ventilated, wicks moisture from your skin well, and doesn't feel stuffy and clammy when temps pick up.
 

Also, the shockcord at the cuffs of the Alpine Light Pants allows you to easily roll them up to boost airflow mid climb. All told, while lighter, thinner climbing pants like the polyester/spandex Himali Equilibrium Stretch Pants are noticeably more breathable, we think the Alpine Light hits a great balance between durability and ventilation for most climbing scenarios. They were my steed of choice for some recent toasty big wall climbs in all-day sun on the towering faces of Zion National Park, and I saddle up in them for everything but the most extreme high-altitude climbing objectives.
 

Features

The last thing you want to worry about mid-climb is fussing around with loads of dangly cords, zippers, and extraneous features. While certain add-ons are undoubtedly helpful in climbing pants, I generally look for a streamlined feature set to minimize weight and bulk and maximize comfort on the wall. For pants I intend to rope climb with (sport, trad, bigwall, etc.) I always want a well-placed zippered pocket at the thigh, for safely carrying a phone or other essentials below my harness leg loops. It's beyond frustrating trying to dig anything out of bunched-up drop-in pockets under a loaded harness mid-climb. The right side zip pocket on the Alpine Light is perfectly sized and placed for this purpose. Aside from the side pocket, the pants feature articulated knees and a gusseted inseam for added mobility, a rear drop-in pocket, and CordLock adjustable hems. I wish there were two rear pockets, but appreciate the weight and bulk savings by including only one. Finally, an easy-to-use, low-bulk integrated webbing belt helps dial in the fit and keep the pants in place.
 

Fit and Mobility

While I love the versatility and function of the Alpine Light Pants, they have a pretty baggy cut (which isn't my favorite), meaning they're not the most stylish pick for use around town. This boosts ventilation and mobility, but I personally gravitate toward slimmer fits with stretchy fabrics. The single-weave, four-way stretch fabric affords a good deal of flexibility without feeling too loose, making dynamic, long-reaching movements a cinch. Finally, the articulated knees and gusseted inseam are key for unrestricted range of motion. In the end, while these aren't the most stylish pants, that's not what they were designed for, and they perform beautifully in the mountains.
 

What We Like

• Extremely durable but reasonably lightweight.
• Dialed-in feature set with all the essentials most climbers want.
• Perfectly-placed zippered thigh pocket.
• Stretchy fabric for unrestricted movement with articulated knees and a gusseted inseam for a boost in mobility.
• CordLock adjustable hems for easily rolling the pants up.

What We Don't

• On the pricey side.
• The fit is on the baggier side, meaning these aren't the most stylish pants for front-country use around town.
• Only one rear pocket.
   

Comparison Table

The Competition

The climbing pants market has exploded in the past decade and continues to expand rapidly. New designs are constantly surfacing, billed specifically for certain climbing disciplines, making it tricky to wade through the masses to find the pants that work for your needs. In testing, I've found that the Black Diamond Alpine Light Pants roughly fall in the middle of the spectrum in terms of weight, durability, and feature set. As such, they are incredibly versatile and feel at home in nearly every climbing category. The closest climbing pants I've tested would probably be the Patagonia Venga Rock ($109) and prAna Stretch Zion ($98). The fit of these pants feels very similar to the Alpine Light (though the most recent Stretch Zion feels a good deal baggier around the ankle), and both have comparable feature sets. The Venga pants are a bit heavier and more durable, with an organic cotton blend that doesn't wick moisture as well but feels more comfortable against my skin. The Stretch Zions have my favorite zippered thigh pocket design and feature a similar weight (11.2 ounces). 
 

For lighter, more minimal climbing pants, I'd direct you to either the Himali Equilibrium Stretch Pants ($95) or La Sportiva Roots Pants ($79). Both hover around 8 ounces, though the Himali pants are a good deal more breathable since the Roots are constructed with a cotton blend. The Roots also have a much more tapered, slim cut than the Alpine Light, but the Himali pants are similarly baggy and breezy. If more rugged alpine ascents are in your future—or even high-altitude mountaineering objectives—I'd point you to some beefier designs. The aforementioned Arc'teryx Gamma Pants ($200) are durable softshell alpine pants billed for light mountaineering but are heavier and bulkier than the Alpine Light. For a bump in weather-resistance and protection, the La Sportiva Supercouloir GTX Pro Pant ($549) is a high-end technical hardshell pant designed specifically for extreme mountaineering missions in the greater ranges. In the end, the Black Diamond Alpine Light Pants offer middle-of-the-road versatility for a broad scope of climbing objectives.
Back to the BD Alpine Light Pant Review  See Our Men's Climbing Pant Guide