Petzl Fly Mountaineering Harness | Review - Outdoors Magic

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Petzl Fly Mountaineering Harness | Review

A technical mountaineering and ski mountaineering harness that is just short of sub 100g

Why We Chose The Petzl Fly Mountaineering Harness: Incredibly lightweight yet functional and reliable

With ski tourers, mountaineers and alpinists all requiring gear they can rely on in the high alpine at a weight that won’t hold them back, the realms of ultra-lightweight gear continue to be pushed further and further towards their limits.

This has certainly been the case with mountaineering harnesses and this new incredibly lightweight offering from Petzl shows just how far they’ve come since their modest beginnings as an arrangement of straps and buckles that could be looped together.

It may resemble something from a Victoria Secret catalogue but Petzl’s new Fly harness – which weighs a meagre 100g – really is a proper, fully-certified sit-on harness.

Photo: Mike Brindley

Who Is The Petzl Fly Mountaineering Harness For?

As you can see, this is a particularly refined product. It’s not going to be one that you’ll be taking continuous lobs on at your local climbing wall (you won’t want to take any falls on it full stop for that matter) but instead, it’s a harness for those who require a something light for glacier travel, for crossing easy climbing sections, or for more technical mountaineering.


In terms of features on the Fly, you’ve got yourself two extremely thin (but reinforced) gear loops and ice screw retainers on each leg loop – and that’s just about it. It’ll come as little surprise that a harness of this weight will be short of attachment points (you’re not going to be carrying a full rack with you). The most interesting aspect of it is simply how Petzl have achieved such a low weight for a functional harness.

The standard weight of this is actually 130g. That’s with the three foam pads in place. Remove them and you’re saving 30g. This choice will of course be down to your planned use of the harness, as winter users may find the additional comfort redundant with clothing providing enough support between you and the harness, whereas Alpine climbers who may have a higher fall potential may prefer the foam left in there.

An additional note on removing this foam is that it also makes the harness extremely packable. You’ll find it much easier to fit into the supplied carry bag with the foam removed.

“You can get in and out of the harness without taking your feet off the floor”

One big advantage this harness has over that of typical climbing harnesses, is that you can get in and out of it without taking your feet off the floor – this makes it ideal for ski tourers with skis on their feet, or mountaineers with crampons attached.

Getting into the harness is pretty straightforward, if a little novel. To start, simply bring the waist loop from behind and join it together at the front by threading a bungee cord through a small loop. Then bring both leg loops around each leg, to then tie them off by threading a small knot through another looped bit of cord. It’s certainly a new way of entering into a harness, but this has all been done to remove the need for any heavy metal buckles.

It’s got to be stressed that the bungee attaching the waist belt isn’t load bearing, so you won’t want to clip anything to this – it’s simply there to keep the harness sat snug around your waist. Everything must go through both abseil loops.

A technical and lightweight mountaineering harness. Photo: Mike Brindley
One of the three removable padded inserts. Photo: Mike Brindley
The Petzl Fly harness is extremely packable. Photo: Mike Brindley

Tester’s Verdict

Jordan Tiernan, staff writer on Outdoors Magic and Mpora

“I’ve been using this harness during the 19/20 ski season until it was abruptly cut short following the Covid-19 lockdowns. For that reason, I didn’t get to use it as much as I’d wished during the spring ski touring season, but I have managed to get a fair few days wearing and rappelling from it.

“I’d recommend spending some time at home practising how to get in and out of this, particularly with gloves on. The bungee/cord system can become pretty tricky when you’ve got big gloves on, but you’ll get used to it over time after a little practice.

“Once in, the harness feels light and you barely notice it’s there”

“Once in, the harness feels light and you barely notice it’s there. I usually wear a M/L in climbing harnesses and the large size was an ideal fit with all my winter layers on beneath, so consider sizing up.

“In terms of comfort, I removed all three foam inserts from the harness, as mentioned above, and I found the fit to be comfortable enough with the extra padding that my base, mid and outer layers gave me. I had no issues on fully weighted 30 metre rapells in this harness, even with skis strapped to my pack. I’d also be happy performing quick 60 metre rapells, although I wouldn’t like to be suspended for too long; this is perhaps where the additional padding will have to be reinserted.

“All in all, this is a seriously impressive lightweight harness that’ll make a mockery of your previously ‘lightweight’ 300 gram mountaineering harness. I can see it being a great choice for those looking to get into some more technical scrambles, or mountain ridges, such as Tower Ridge or a Cullin traverse, both in summer and winter.”

Petzl Fly Mountaineering Harness

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