Arc'teryx M270 Harness

Once upon a time, adjustable leg loops were the sign that you were an 'all-rounder', that you had a pair of crampons as well as rock shoes. The logic was if you needed to put your harness on after your crampons, then the leg loops would need to open fully so that you did not need to step into them. Nappy-style harnesses like the Black Diamond Bod got around this problem with their design but they tended to be less comfy for summer climbing. The traditional padded waist- and two-leg loops style is better across the seasons, but anyone who has tried to do up the waist and leg loop buckles of a fully opened adjustable harness, on a spindrift blasted mountain side while wearing gloves will know what an infuriating tangled puzzle of straps and padding they can rapidly become.

The M270, lithe, strong and winter-specific, 80 kb
The M270, lithe, strong and winter-specific
© Toby Archer

I guess like many others, when I got my first harness with 'zip-lock' buckles rather than traditional double-backs I stopped fully opening the loops on my harness. When winter climbing you then have two choices, just remember to put your harness on before your crampons - easy enough to do - or find a safe place to sit whilst you carefully pull your harness on over crampons - also not nearly as tricky as those who haven't tried might think, at least with my size 42 feet. Once some climbers had rejected the need for fully opening leg loops, the next step was clearly to rethink what else they wanted in a winter harness and the answer was: not much. Most modern harness designs are getting lighter, but when you have warm layers of clothes on anyway, harness padding also becomes less important. Over the last half a decade or so, it suddenly seemed that many top winter climbers, be that on water ice, continental style bolted mixed or in Scotland were wearing lightweight sports harnesses, notably the Petzl Hirundos. Arcteryx, long a leader in harness innovation, have fully embraced this trend with the M270, a fixed leg loop, super light and simple harness designed specifically for ice and mixed climbers.


"A fixed leg loop, super light and simple harness designed specifically for ice and mixed climbers."

The M270 uses Arcteryx's 'Warp Strength Technology', where the fibres of the webbing that would normally form just the structural strength of a harness, are spread out, meaning the webbing can be both the strength and the 'padding' - the comfort - of the harness. By doing this, Arcteryx's harnesses are lighter than traditional designs where padding is added. It also makes them very compact when folded up - a bonus for any winter climber whose day start with a multi-hour hike to get to the ice. With the M270, Arcteryx has gone all out for lightness and compactness using “Vapour Mesh” for the leg loops. This is what it sounds like, a strong, stiff mesh that you can see through. The leg loops are wide and, despite being 'just' mesh, give plenty of support. Overall, the design and technologies used make a remarkable light and compact package, and worn over my normal winter layers, the harness is just as comfy to hang in as any other whilst being basically unnoticeable when being worn for climbing and walking around in.

Toby Archer ice climbing in the Arc'teryx M270
© J Ormala

Toby Archer on steep ice at Angelniemi, SW Finland, with the M270, 108 kb
Toby Archer on steep ice at Angelniemi, SW Finland, with the M270
© J Laajarinne

The racking provision on the M270 is worthy of note. Arcteryx have given the harness just two normal racks (the plastic stiffeners on them are removable so you can choose to have them sloping forward or backward), one very light webbing loop at the back - just fine for my belay device and prussiks - and then 15 ice clipper slots. Despite being a weekly ice climber for over a decade of winters, I didn't own any clippers, having made DIY ice screw racks years ago and always having been completely happy with them. Hence one important consideration is that if you don't own clippers you are almost certainly going to need to buy some to get the most out of the M270! If you have clippers already, then fine, but otherwise you'll need to add the price of them to the M270's already not insubstantial cost.

For pure ice I've found between the two big gear racks and the ice clippers the M270 is good. I often carry my screamers and quickdraws in winter on an over the shoulder sling anyway, but there is plenty of room on the racks if you prefer that. For British-style mixed climbing with nuts, hexes and cams along with the odd warthog or turf hook, I definitely needed to use a bandolier (just a 60 cm sling works for me in winter) in addition to the M270's racking. If you hate bandoliers yet carry a big rack in winter, then the M270 may not be the harness for you for that simple reason.


"The racking provision on the M270 is worthy of note."

Generally falling off ice climbs is a bad idea, but on my first day out with the M270 I did take a decent sized fall off a mixed climb, and from that I can assure readers that the M270 worked just fine! If I do have a problem with it, it is on sizing. I looked carefully at Arcteryx's size chart and found I was in the middle of 'medium' for waist size, but definitely 'large' for thighs. Being non adjustable leg-loops I had visions of not being able to get the medium over my cyclist's thighs so ordered the large. As it turn out there is loads of room in the leg loops - so much so that they move around and sometime need readjusting when abseiling to be comfortable; not ideal. Obviously trying one on is always the best option, but if that is not possible I would pay more attention to waist sizing and not worry about the thigh measurement so much. One other minor gripe is that the excess tape from the waist belt only has one loose loop to hold it out of the way, and this doesn't work too well. I've ended up tucking it in the waist band. No problem with winter clothing on, but could be uncomfy otherwise.



Overall the M270 is a lovely but rather specialist bit of kit. Arcteryx's own description 'designed for performance-focused ice and mixed climbers' seems very fair; it won't be the difference between you getting up Tower Ridge or not, but for those pushing the harder grades, if it's racking system works for you, the M270's lithe strength makes it a very attractive choice. A winter-specific harness may seem a bit decadent to some, but then some of us spend a third or more of our climbing year in crampons, plus of course it will mean your summer harness will wear out less quickly!


Arc'teryx M270, 138 kb



  • Lightweight: 275g
  • Low profile
  • Two drop seat buckles
  • Self locking buckle
  • Thermoformed tie-in point
  • Belay loop
  • Low-profile webbing haul/gear loop
  • Wear safety markers on tie-in points
  • Fifteen ice clipper slots
  • Large width 'WST' (Warp Strength Technology) swami belt
  • Two injection molded reversible and removable gear loops
  • 'Sure Fit' elasticized leg loop connectors provide a snug fit
  • 'Vapor Mesh' leg loops



Marmot Genesis softshell jacket: Toby ice climbing in North Wales, 134 kb

About Toby Archer

Toby is based in Finland. He describes himself as: "a writer and researcher specialising in international security politics; finally no longer a PhD student; hopeless but enthusiastic climber; part-time gear reviewer; keen multi-role cyclist; idealist and cynic"

Climbing keeps him from getting too depressed about politics. He blogs about both at:

Light from the North - chilled thoughts from the top of Europe.

For more information visit Arc'teryx M270
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