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Arc'teryx FL-365 Review

A versatile and mobile harness good for all disciplines, but with a high price tag
arc'teryx fl-365 climbing harness review
Credit: Arc'teryx
Price:  $145 List
Manufacturer:   Arc'teryx
By Andy Wellman ⋅ Senior Review Editor  ⋅  Nov 12, 2019
  • Hanging Comfort - 35% 6.0
  • Standing Comfort and Mobility - 20% 8.0
  • Features - 20% 6.0
  • Belaying Comfort - 15% 6.0
  • Versatility - 10% 8.0

Our Verdict

Arc'teryx discontinued the FL-365 harness as of Spring 2020.
Automatically cinching elastic leg loops
Large amount of gear storage
Four ice clipper slots
Not super light
Not very comfortable for belaying
The Arc'teryx FL-365 is a streamlined harness with fixed elastic leg loops that effectively snug up to the perfect fit regardless of how much clothing is being worn underneath. It is very similar to the other Arc'teryx harnesses, except for the difference in leg loop design, which are made of fixed, auto-cinching elastic. It is versatile for all styles of climbing, from rock to ice, and is notable for its very supple design that uses Arc'teryx's Warp Strength Technology to make a very thin, but wide, waist belt and leg loops which move easily as you do and are easy to stuff into the climbing pack. The main knock against this harness is its price tag, which is a bit out of line when considering the higher-performing options for around half the cost.

Our Analysis and Test Results

Despite the "Fast and Light" connotation that comes from the "FL" in its name, this harness is only 0.6 ounces lighter than the heaviest Arc'teryx choice, and the only noticeable difference is in the design of the leg loops. Instead of the clunky adjustable buckles, these leg loops have retractable elastic bands that stretch as much as needed to put the harness on but then cinch up snug against the leg once in place, an innovative design that we like. For this reason, we enjoy this harness more than the AR-395a and would recommend it first not only for its more refined design but also its slightly lower price tag.

Performance Comparison

arc'teryx fl-365 climbing harness review - the fl-365 is a "fast and light" harness, which essentially means it...
The FL-365 is a "fast and light" harness, which essentially means it has elastic fixed leg loops rather than buckle adjustable ones, as you can see here. These leg loops stretch as you put the harness on, and then automatically cinch snug around your leg.

Hanging Comfort

This harness uses Warp Strength Technology to disperse the weight of a climber throughout the entire waist and leg loops, rather than a design where there is a thin piece of webbing with padding over the top. It seems to work quite well, but the design also has far and away the fattest (bottom to top) waist belt of any that we have tested. Where it rests against the middle of the lower back, we like the fat design, but when hanging, we noticed that because it is so fat on the side of the body as well, it crushes in against our kidneys and lower ribs even more than most. We also have a problem with the leg loop design. Since it is made of such a thin piece of webbing, it tends to twist and gouge into our femoral region on the inside of the leg more than most. Don't get us wrong, no harness is all that comfy to hang in for protracted amounts of time, but compared to a lot of top-quality competition, this one is not very comfortable.

arc'teryx fl-365 climbing harness review - hanging belays can be an uncomfortable experience, but one that we...
Hanging belays can be an uncomfortable experience, but one that we take in stride when we leave the ground for the day. Here Stefan hanging out over the void on Levitation 29.

Standing Comfort and Mobility

The most significant advantage of the design is that it's very supple and mobile. We love how the harness moves with us as we walk about. That said, the very fat waist belt again presents a bit of a problem for us on warm days, when we find it to be quite sweaty. Also, when carrying a large rack, we feel it tends to slip down and chafe a bit. The freely moving gear loops and the very thin waist belt make this an excellent choice for wearing under a pack, and its mobility makes it a good choice for alpine and mountaineering use. However, due to its bulk, we find it to be far more noticeable to wear than most harnesses.

arc'teryx fl-365 climbing harness review - one of the best parts about the very thin design of this harness is...
One of the best parts about the very thin design of this harness is how flush it sits next to your body, making it an ideal choice for carrying a pack, or in this case the rope and some rack, on an approach up the slabs in Red Rocks.


This harness has all of the features you could conceive of a harness having, but we don't like the way that they perform quite as much as the features found on the highest rated Petzl models. It has four large, plastic-covered gear loops that are easy to clip and flexibly rest against the body, but we don't like how they taper downward to a point (we prefer a flat gear loop) because then all the biners crowd into each other and try to overlap, making it harder to unclip the one you need quickly. We also find that the sewn-on keepers for the webbing tail of the doubled-back waist buckle require the tail to be woven amongst the gear loops, and it gets in the way of our clipping once again. This harness does have the nice option of four ice clipper slots, and we think that the design of the elastic leg loops is superior to the bulk of the adjustable buckles found on the AR-395a, and so rated this one slightly higher for features.

arc'teryx fl-365 climbing harness review - you can see many of the features found on this harness here...
You can see many of the features found on this harness here, including the ice clipper slots. You can also see how the keeper loops for the tail of the waist belt buckle tends to hang in the way of the gear loops, which we wish wasn't so. You can also see how the gear loops with a low point tend to cluster the carabiners together, which we find makes them slightly harder to quickly and easily unclip.

Belaying Comfort

We think the FL-365 makes belaying more comfortable than the 395-a. We find that when holding a climbing friend while belaying, their weight is localized almost entirely on the leg loops, particularly as they wrap around the inside of the leg. These leg loops taper significantly in this region, and the added bulk means that we were more likely to need to adjust how it is hanging quite a bit, but also means that the sharp edges of the webbing don't gouge into our skin as badly as we would expect. Even still, we don't find extended belay duty in this harness to be all that pleasurable.

arc'teryx fl-365 climbing harness review - stefan belays on a sloping ledge near the top of levitation 29, a...
Stefan belays on a sloping ledge near the top of Levitation 29, a classic 10 pitch route in Red Rocks. The FL-365 is a bit more comfortable for belaying than the AR-395a, but is still not the most comfortable.


This is a very versatile harness, usable for sport climbing, trad and long free routes, and even ice and alpine climbing. With its thin waist belt, we feel like it is even a good choice for mountaineering. However, it is heavier and bulkier, and not quite as comfortable as the harness we consider to be the most versatile, and its fairly snug fixed leg loops do not provide the same level of adjustability as models that have adjustable buckles.

arc'teryx fl-365 climbing harness review - we used this harness for many days of sport cragging, and also on...
We used this harness for many days of sport cragging, and also on long multi-pitch routes in Red Rocks, and think it is easily one of the most versatile. Its feature set also make it a great choice for winter climbing, so it is indeed a "quiver-of-one".


This harness retails for a little bit less than its comparable Arc'teryx cousin. Since we like the leg loop options on this harness better, we think it is a better buy considering it's also a bit cheaper. However, there are a handful of harnesses that we think perform quite a bit better and are way more affordable (like half as much!), so we wouldn't necessarily consider this to be the best value purchase.

arc'teryx fl-365 climbing harness review - the thin face climb "watt's tots" at smith rock was the first sport...
The thin face climb "Watt's Tots" at Smith Rock was the first sport climb in the US. The versatile FL-365 is a good comfortable choice for sport climbing.


The Arc'teryx FL-365 is designed to be "Fast and Light," with fixed elastic leg loops to cut down on weight and bulk. It is one of the most versatile harnesses you can buy but comes at a pretty high price compared to the competition.

arc'teryx fl-365 climbing harness review - whether multi-pitching or cragging, winter or summer (or dry rock in...
Whether multi-pitching or cragging, winter or summer (or dry rock in the winter, as in this photo), this Arc'teryx model makes for a versatile choice. Stefan pulling the pitch 2 crux of Levitation 29.

Andy Wellman
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