The lightest sport climbing specific harness with adjustable leg loops, the Black Diamond Siren is ideal for a woman looking for a lightweight harness with adjustability. It has a slim, compact profile that is light and mobile, but not very comfortable to hang it. You might even forget that you have this harness on, until you have to hang in it and your toes go numb. It has a unique Mondo gear loop with a central divider, which holds a lot of quickdraws and prevents them from shifting too far to the rear on overhanging terrain. It also has abrasion resistant patches on the waistbelt and leg loops for added longevity. If you are looking for a lightweight, sport-specific harness and don't plan on hanging in it for very long, then this model is a good choice. Otherwise, our Editors' Choice winning Camp Supernova is a much better option. It's only .5 ounces heavier, much more comfortable, and more versatile to boot.
Black Diamond Siren Review
Cons: Little padding, uncomfortable to hang in
Manufacturer: Black Diamond
Our Analysis and Test Results
This harness is made with Black Diamond's Dual Core XP Construction, with two bands of webbing and 3D mesh paneling to help distribute the load. It comes with BD's trakFIT leg loop adjustment system, which is an adjustable fixed loop. It has one Mondo (aka large) rigid, plastic-coated gear loop on each side, but they have a plastic separator so really there are four loops total. The waistbelt and leg loops have abrasion resistant patches, and there is no haul line loop or extra loop in the back for a chalk bag.
Standing & Hanging Comfort
When it comes to standing comfort, the Black Diamond Siren was the most comfortable out of all of the models that we tested. It is light and hardly detectable while climbing and walking; the waistbelt is only two inches wide (compared to four inches on the Arc'teryx AR-385a), and it is super thin. This proves to be its downfall when hanging, however, and in that metric it received our lowest score. There is little to no padding on the waistbelt and legs and our legs quickly went numb in our hang test. Although manufacturers may not think that a sport climbing harness needs to be as well-padded, our sport climbing testers spend a lot of time hanging while working on a project or belaying someone who is. So, unless you're not planning to hang around too long - or you're just going for the send - we recommend an all-around harness like our Editors' Choice winner for everyday sport climbing use.
This harness was designed as a lightweight sport climbing harness, and in that sense we think Black Diamond did a great job. It's easy to move in and one of the lightest harnesses that we tested (11.5 ounces in a size small). The only harness that was lighter was the Mammut Zephira (10 ounces) and while that harness was more comfortable to hang in, we did not like the large angled gear loop which caused all of our quickdraws to shoot towards the back of the gear loop when the climbing got steep. While the Black Diamond Siren does have a large "Mondo" gear loop, it comes with a plastic divider to avoid that problem. You can fit around seven quickdraws on each side of the divider, or fourteen total per side of this harness, which is plenty for even the longest of sport routes. The Mondo loops are fixed and plastic-molded, sitting away from the harness for quick and easy clipping and unclipping. The loops will not fit a lot of traditional gear though, so if you are mostly a sport climber but occasionally like to do long routes, you'd be better off with a more versatile harness like the Camp Supernova or Black Diamond Primrose.
There is no haul loop on this harness, and the lack of padding and thin, mesh waistbelt kept our back from getting too sweaty when climbing on a hot day. It also folds down very small, equivalent to the notoriously compact Arc'teryx models. This is a bonus if you need extra room in your crag pack for your chair, speakers, sunshade, two puffy jackets, thermos and gourmet lunch.
The Black Diamond Siren also scored better than any other harness in this metric. The thin waistbelt did not impede our movement, and the elastic on the leg loops made funky leg maneuvers easy to do.
This harness works well for sport climbing and gym climbing where not much gear is required. It does not work well for trad climbing or multi-pitch climbing since there are only two gear loops and no haul loop.
This is the lightest sport climbing specific harness with adjustable leg loops, which is a nice option for women with different proportions from what the different manufacturers deem "average." The trakFIT system doesn't adjust quite as much as a buckle — we were able to get about 2-3 inches of adjustment, compared to 4-6 inches on a standard buckle, but that is more than the 1 inch or less that you will find on other fixed leg harnesses, like the Mammut Ophira and Zephira models. The slider is a neat feature: it is small and light, and does not need to be double-backed, so it adds almost no weight or complication to the harness, while allowing it to fit a wider range of women and/or accommodate heavier clothing layers on chilly days.
The leg loops do detach with a hook closure that is slightly more difficult to use than a buckle. It is also difficult to adjust the rise, as the elastic on the legs loops goes around and through the hook closure. However, once you adjust it the first time it won't lengthen or shorten accidentally and you will not need to mess with it again.
The Black Diamond Siren is most at home sport climbing or gym climbing. Black Diamond recommends this harness for light and fast missions, and we could see taking this up a route like the Snake Dike on Half Dome in Yosemite National Park, which involves a lot of hiking, little gear, and slabby belays at natural stances. Otherwise, we'd want a beefier and more comfortable harness for long routes that have extra features like haul loops and more racking space.
For $70, this harness is mid-range in price. Unless you sport climb exclusively, a more versatile and less expensive harness like the Black Diamond Primrose — which is only an ounce heavier — is a way better deal. This harness does have BD's "Bombshell" abrasion resistant coating on the waistbelt and leg loops, which should help increase the longevity of the material.
We have a few mixed feelings about this harness. While it is light and mobile, and great for steep sport climbing, it is not very comfortable to hang in, and truth be told, sport climbers spend a lot of time in their harnesses either working a route or belaying someone who is. If we could be sure that you'd never have to hang in this harness for more than a minute, we'd recommend the Siren in a heartbeat, but the reality is a little different, and we think a harness like the Camp Supernova with a little more padding and a lot more comfort is probably a better bet.
— Cam McKenzie Ring