Black Diamond Momentum 3S Harness

Black Diamond Momentum 3S, Blister Gear Review.
Black Diamond Momentum 3S

Black Diamond Momentum 3S Harness

Weight: 370 g / 13 oz

Sizes: S-XL

Size Tested: M

Color: Coal/Lava

Season: 4-season harness

Waist Belt: Bullhorn-shaped OpenAir waist belt using Dual Core Construction

Leg Loops: Adjustable

Buckles: Pre-threaded Speed Adjust buckles on waist belt and leg loops

Gear Loops: 4 pressure-molded gear loops

Haul Loop: 12 kN-rated haul loop

Climber Type: Primarily bouldering and sport climbing

Time Tested: spring and summer of sport climbing

Test Locations: Sinks Canyon, Lander WY; Wild Iris, Lander WY; Wolf Point, Lander WY; Rock Springs Buttress, Jackson WY, Cueva de la Cabra, Jackson WY; Teton Canyon, WY; Grand Teton National Park

MSRP: $59.95


I live in Wyoming, and I have access to some amazing sport climbing in Lander. So while I am first and foremost a boulderer, I’ve spent more and more climbing days tying into the sharp end, and as a result, I recently upgraded to the Black Diamond Momentum 3S.

During these past years sport climbing, I’ve realized that while most climbing harness are very safe, there are certain features—like the design of the waist belt and adjustable leg loops—that can dramatically improve how a harness fits, packs, feels, and breathes.

I was looking for a lightweight, low-profile, comfortable harness that would stand up to the constant abuse of projecting sport routes. The Momentum 3S seemed to fit the bill. Black Diamond markets the Momentum 3S as an inexpensive, “entry level 4-season harness,” and I wanted to see how it compared to other harnesses geared toward specific disciplines.

Waist Belt

The Momentum 3S has a bullhorn-shaped OpenAir waist belt built with Dual Core Construction. This waist belt is supposed to maximize breathability without compromising support and padding. The waist belt is made from two pieces of structural webbing on the top and bottom with mesh running in between. This mesh gap combined with Black Diamond’s OpenAir foam greatly increases breathability while still evenly distributing the load.

Black Diamond Momentum 3S, Blister Gear Review.
Dual Core Construction

I have found that the Momentum 3S breathes exceptionally well, and I have been very impressed that the harness does so without sacrificing hanging comfort.

Recently I’ve been projecting a 5.13 sport route called Super-G at my local crag in Teton Canyon. Because the route is highly technical, I’ve spent a lot of time hanging in my harness and refining beta. The Momentum 3S is a good tool for this kind of projecting since the padding and the OpenAir design ensure that I never come off the route feeling sore from hanging around for more than an hour at a time.

Adjustable Leg Loops / Buckles 

The Momentum 3S has adjustable leg loops with speed adjust buckles. This makes the Momentum 3S a far more versatile harness than the Petzl Sama or Black Diamond Ozone, both of which have fixed-sized leg loops.

The leg loops on the Momentum 3S are easy to adjust, making the harness a four-season harness that easily lets you add or remove layers. It’s a good choice for climbers interested in alpine routes or trips into the mountains. And while you don’t usually need multiple layers at a sport crag, I think the adjustable leg loops will be a good feature for colder days.

I actually found this feature useful this summer while climbing on Jackson’s Rock Springs Buttress—an exposed, alpine crag. Mornings at the Buttress are often cold, and it’s nice to wear heavier pants while warming up. But once the sun hits the south-facing wall, I like to shed the outer layers and still cinch down the leg loops for a secure fit.

I’ve found that the speed adjust buckles on both the leg loops and the waist belt are so easy to adjust, they worked very well at the sport crag. And while I thought the additional buckles would increase weight, the Momentum 3S weighs 13 oz—exactly the same as the fixed-leg loop Petzl Sama.

I really liked the adjustable leg loops on the Momentum, and haven’t had any problems with them. That said, if you know you’re just going to be sport climbing in the summer, I might recommend a fixed-leg loop harness. It’s just one less thing you have to think about, which can be nice if you don’t need the added versatility of adjustable leg loops. I still grab the Petzl Sama when I head out to a sport crag on a warm day because I know I won’t need to adjust the leg loops. But on cold days when I’m wearing extra layers or when I go to the mountains for an alpine route or ski mountaineering, I will undoubtedly take the Momentum 3S.

Momentum 3S, Blister Gear Review.
Matt Pincus on Paul’s Boutique, 5.12c, Cueva de la Cabras, Jackson WY. (photo byLiz Schafer)

Gear Loops

Black Diamond 3S Momentum, Blister Gear Review.q=
Gear Loops

The Momentum 3S has four pressure molded gear loops. These four full-sized gear loops are designed to accommodate everything from a set of quick draws to a full trad rack. They not only provide ample room for racking gear, but they’re also rigid and make grabbing gear off of them quick and easy. This is a nice feature for those occasions when you’re at a tenuous clip or gear placement.

The Petzl Sama, a more sport climbing-specific harness, only has two rigid gear loops in the front and two flexible ones in the back. While having more gear loops doesn’t affect sport climbing performance, this is an important thing for trad climbers and mountaineers to be aware of and is an added advantage of the Momentum 3S.


I have only been climbing in the Momentum 3S for a couple months, so I can’t comment on how durable the harness will be in the long run. But so far, the harness is holding up well and still looks new after several months of almost continuous use.


The Momentum 3S is designed to accommodate different disciplines across four seasons. It’s a jack of all trades, not a master of one.

So while any type of climber could use the Momentum within their chosen style, a big wall climber might prefer a beefier harness that was even more comfortable to hang in for extended periods of time, while a dedicated sport climber might appreciate the simplicity of a harness with fixed leg loops.  

Momentum harness, Blister Gear Review.
Matt on Super-G, 5.13a, Teton Canyon, Driggs, Idaho. (photo by Sherry Pincus)

Bottom Line

The Black Diamond Momentum 3S is an extremely versatile four-season harness that is designed to accommodate all disciplines of climbing, and work for  everyone from experts to beginners.

Beginners looking for a quality, inexpensive harness that will allow them to explore different types of climbing, both indoors and outdoors, will be well-served by the Momentum 3S. Intermediate and advanced climbers that dabble in a variety of styles could consider the Momentum 3S a “one-harness quiver.” But I think climbers who primarily stick to one discipline may prefer a more style-specific model.

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