Field Journal

Testing the New Arc’teryx Lithos SL Harness
Written by Mark Bullock // Photography by Mark Bullock & Arc’teryx

The new Lithos SL Harness is Arc’teryx’s pinnacle sport-climbing harness, engineered for redpoint attempts, competition climbing, and high-end performance. To review it for Sidetracked, Mark Bullock took it on some West Country HVS trad routes.

I’ve been climbing for over 20 years and never owned an Arc’teryx harness. I’ve lusted after them a few times – with their distinctively wide ‘swami’ or hip belts and funky colour palettes, I’d seen friends wearing them, but been put off by the significantly higher price point compared to almost any other brand on the market.

So I was excited to open my package – direct from Vancouver – and get a pre-launch look at one of their pinnacle pieces of equipment. It’s their new streamlined flagship harness designed for sport climbing, built around an updated sizing system, as well as lightweight and durable construction. Out of the box, I was surprised by how stiff it felt. Featuring the next evolution of Warp Strength Technology, intended to evenly distribute weight across the waist and leg loops, the Warp 2.0 fabric improves on previous materials to deliver a thinner, lighter, and more durable load-bearing structure. But it felt so stiff, I was sure it wouldn’t be comfortable to wear. Added to that, it’s oh-my-word minimal. Compared to my current harness, the leg loop adjusters and the belay loop are absolutely tiny. Surely this was going to be like wearing a Kevlar cummerbund supported by a wire saw?

No. My very first wear was using autobelays in my local wall. ‘Pleasantly surprised’ would be vastly understating it; I was genuinely shocked how comfortable it was.

I have two existing harnesses in my gear store at home, but essentially I just use one for everything. I don’t sport climb enough to need a super light harness in addition to a trad harness, and similarly, I don’t need something that can cope with big-walling or massive aid racks. My main harness is Black Diamond. I’ve had it for three to four years and I’ve loved it. It has never once occurred to me that it in any way restricts my movements – until, that is, I wore the Arc’teryx Lithos SL and felt sort of naked.

It felt like there was nothing there, and I definitely had more range of motion in my hips, no bunching around my belly button. Pretty hard to describe this sensation, but the Lithos SL helped with a problem I didn’t even know I had. This might be due in part to the design – the rise from leg loop to waist belt – but also in the way the Arc’teryx fit and sizing works. The harness is unisex, and they offer sizes 1A–6B; it’s meant to be a ‘neutral fit’, with customizable waist-to-leg-loop ratio. This is what Arc’teryx have to say: ‘The Lithos SL features a new industry-first sizing system that replaces gender-specific fits with six waist sizes and two leg loop options per size, providing more freedom of choice across a range of body shapes and allowing climbers to dial in a truly personalized fit.’

My next time wearing the Lithos SL was on a trad trip to Cornwall. Loading the two gear loops (one each side) with a double set of nuts, some offsets, six or seven cams, plus extra slings and screwgates, nut key, and belay plate, was frankly is too much. In Arc’teryx’s defence, this is not what the Lithos SL is designed for at all. However, the swami didn’t buckle, fold, nor slide down – some heavily laden harnesses can do this, pulling my trousers out of my jacket and revealing a cold spot on my lower back. It held its shape and position perfectly, and was only really limited by the size of the gear loops. It is obviously designed for a set of quickdraws when clipping bolts, but I really wanted to wear it trad climbing.

I have to say I love it. If we hadn’t been climbing middle-grade multi-pitch, and I’d been carrying a more refined rack (such as just small wires and two to three small cams) for a shorter more obvious pitch, it would have coped perfectly well. In the end I wore slings around my body – which I prefer anyway – and made do with sifting through a bit of clutter each time I needed a runner. So it’s clear that it can work for trad after all, depending on your needs and preferences. And as for all-day comfort, while I was on semi-hanging belays, the surprisingly firm Warp 2.0 swami did not dig in at all; it seemed to just support me, using that surface area to perfect effect. We climbed maybe 15–20 pitches across the day. I didn’t take it off once, and had no sore spots.

The belay loop is pretty crazy. It’s tiny. Less than a centimetre wide, but more than double the strength of previous Arc’teryx harness belay loops. Constructed from high-strength spun fibres encased in a protective sheath, Arc’teryx have managed to improve flexibility and eliminate any hard-wearing points caused by structural stitching.

The TL;DR verdict

A super light – but extremely comfortable – harness that is so beautifully engineered it’s made me want to use it for climbs that are beyond its remit!