Review: Osprey Mutant 38L Climbing Pack

I’ve had a few Osprey packs over the years, from a monster 65L Aura AG that I lugged around Australia and New Zealand, to a svelte 2.5L Kitsuma that was my hands-free hydration system for local, lockdown wanders during COVID-19. My favourite is an aged Tempest 16, which is my go-to day pack for fell walking and is definitely testament to Osprey’s craftsmanship as it just keeps going.

I like to think I take a fairly minimalist approach to my gear, but I’ve definitely found backpacks to be a bit of a sticking point in this respect, you can’t really just have one pack that covers every activity. Sure, you might cover a few bases with a particularly versatile hiking pack, but when it comes to climbing, especially the colder variety, there are a few things your rucksack really does have to have.

With that in mind, I’m looking for a climbing pack that’s going to work for winter suffer-fests and the midgier, halcyon summer rock days as well. I need tool locks, gear loops and somewhere to store crampons on the outside of my bag as faff frustrates me deeply, which brings me neatly to; faff-free openings, closures, compressions straps and a convenient pocket for the things I need to keep handy. And speaking of handy, I really, really don’t want to have to take my gloves off to fasten or unfasten things if I can possibly avoid it. When the wind is gusting and you’re being smacked in the face with spindrift, the last thing you want is fiddly fastenings.

I need a tough, rugged rip-stop construction that can handle abrasion from hauling and squirming my way up esoteric chimney climbs, a slim profile that isn’t going to have me wedged in said chimney, and a comfortable, form-fitting back panel. Quite importantly, I like my climbing pack to compress down as much as possible once all the gear and ropes have been dumped out, the sandwiches have been eaten, and it’s time to climb.

I’ve been testing the Mutant 38L in Mars Orange (which is a little more on the red end of orange and a great, highly visible hue for mountain activities) and a size S/M. The availability of size options is always a plus with Osprey, as an ill-fitting pack can really put a downer on your day. The Mutant fits me well in terms of length and width, and the waist belt sits so as to not press on my hip bones, something I’ve found to be a problem with unisex style packs in the past. The chest straps are moveable to suit your shape, or removable entirely, as are some of the other multiple straps on the pack.

I can’t decide if it feels a little over-engineered or in fact, just a very adaptable pack

It feels pretty light, lighter still when you remove the lid. There’s a flap jacket which protects the draw-cord opening if you decide to leave the lid behind, a helmet carry which can be attached to the top or front of the pack, a rope stay, gear loops to the waist belt and loop for your ice screw holder. There are definitely straps. I can’t decide if it feels a little over-engineered or in fact, just a very adaptable pack.

Osprey would not be the first brand that comes to mind if you said ‘climbing pack’ to me. I associate the brand more with hiking and backpacking, and my reservation with an Osprey climbing pack would be largely to do with the amount of straps and slightly surplus-feeling features their designs sometimes seem to have. That said, Osprey athlete Kristin Harila is a bit of a hero of mine, so if it’s good enough for her…

Whilst the straps are all useful elements on this pack, when pulled tight on a windy day there is definitely that familiar flapping to put up with. However, it looks good, feels robust and has everything I want and then some, so maybe my reservations were unfounded after all…

Comfort

I’m really chuffed with how comfy this pack has been so far. The Mutant comes with an Atilon framesheet and dual aluminium stays in the back panel which can be removed independently of each other if you like to travel really light or prefer less rigidity. Even without this, it was comfortable on a long day out.

Adaptability and Versatility

The Mutant easily transitions between single-pitch crag days to full-on winter excursions in the corries. Basically, you can set this pack up to suit how you like to carry your gear – helmet and rope inside or outside, lid or no lid, etc. – but if you already have a system that works, it might feel like some of these features are a bit surplus.

Water-repellency

Some brands profess to have decent water resistance in their packs, but proofing can come at a cost to weight and stretch in the pack’s fabric. The Mutant’s PFC/PFAS-free DWR coating does a brilliant job at keeping your stuff dry on wet and snowy days, but is still lightweight and has a decent amount of give.