Friday, 18 August 2017 09:27

Osprey Mutant 38l long term review

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First impressions are important but when you're spending around £100 on a 38 litre pack you want to know how it feel 6 months, or a year, later. We gave Bryn the job of putting the Osprey Mutant through a long term test and review to see how it holds up to prolonged use.

What Osprey say:

A pack designed for year-round ascents. Super light, flexible, strippable and seasonally versatile you can rely on this perennial climbing partner. In the winter you will welcome the snowshedding backpanel, side ski carry loops and dual ToolLock™ system which allows quick and secure ice axe attachment. In the summer you'll be feeling the heat but enjoying the EVA die-cut ventilated shoulder harness and the ability to strip 380g from the total pack weight by removing any features you won't need. The main entry to the Mutant 38 is through a floating and removable top lid, which means you can overload your pack like a packhorse or remove the lid totally for greater head clearance and lighter weight. Lesser climbing packs have minimal weather protection and compression when in this mode, but not the Mutant 38. Utilise the built-in FlapJacket™ that not only provides a weatherproof closure; it keeps your gear fully compressed. Also integrated into the top pocket you will find a rapid deploy mesh helmet storage pouch. The reverse-wrap Splitter™ hipbelt delivers your choice of comfort, minimalism or gear racking options. Rock climbing in the summer or ice climbing and ski touring in the winter, your Mutant will never be off your back.

Weight: 1.19 kg (M/L)

Maximum Dimensions (cm): 63 (l) x 27 (w) x 25 (d)

Main Fabric: 210D Nylon Dobby


On test with My Outdoors:

This is a long term review of the Mutant 38. I have been using it regularly since last autumn and overall it has not disappointed. It has mainly been used as a hauling pack for multi night trips, scrambling, and overnight camps high in the Peak District and the Cumbrian Fells. It is a versatile pack in this sense and not just to be devoted to crags in my opinion.

OspMut 7

The Mutant is a classic climbing pack; it has no side pockets nor hip belt storage and is easily stripped to make a lean system for routes on rock or ice. Crucial for packs designed to be scuffed across rock and dropped on the floor regularly, it is pretty tough, made from 210 denier nylon The only noticeable damage in over ten months of use has been some small holes on the mesh across the back system. These don't seem to want to spread and proved cosmetic.


In my experience, Osprey packs have a deceptive amount of room. The capacity of the Mutant is great and enhanced by its floating lid. This allows you to keep stuffing extra jackets into the top and still fit a 60m rope across the top, slipping the hanging rope behind the compression straps. There is no compression strap for ropes which may bother some.

The pocket in the lid is ample enough for weather gear and water and there is asmaller mesh zipped pocket in the top of the inner compartment, which is adequate for small sundries.

The floating lid is easily adjusted, is removable and reveals a flap closure. This is good for reducing weight and improving head manoeuvrability, but the main snag with the 'Flapjacket' is there is nowhere to stow it when you use the full lid set-up. If you stuff it between the drawstring top closure, then it allows spin-drift and driven rain into the main compartment potentially. I have been just laying it across top of closed inner pack before cinching the top lid. It's not a serious failing, just a lack of attention to design from Osprey.

OspMut 6

The ice axe attachments are easy to use, with glove-friendly elasticated stays at the bottom and side, allowing quick deployment. The compression straps on the side of the pack have three points of adjustment and allow skis to be inserted. The helmet 'bra; a stretchy mesh deployed from a lid pocket works reasonably well, but does flop around a little on the move. The helmet stays put however.

OspMut 2

Another area that may bother some climbers is you can't fully strip out the belt. The belt is a gear racking option for some

OspMut 3

but if you're on a multi-pitch route in a harness, then you're likely to rack your hardware there, thus the belt could go. This would be a minor weight saver, but if the belt were removable then there is less clutter to snag as you climb. Currently the option is to wear the waist-belt or fold it behind the pack. When folded to the rear, the gear hanging options have gone anyway.

OspMut 4

A feature which is a little odd is there is an internal gear compression strap across the top of main compartment. While seeming a good idea, in practice offers little benefit in my opinion. I've found that the drawstring enclosure and side compression combine to work effectively enough. Osprey could have improved this overall by making a rope and compression strap over the closure to the main compartment.

Taking the niggles aside, let's look at how it performs overall. It is designed to carry decent weights on the approach or through routes in the mountains. I can't really get more than 13kgs in it before it's crammed anyway and it carries this weight superbly. I've used the pack more for winter backpacking and mountainous treks than alpine climbing. It remains comfortable and requires little adjustment once I cinched in all the strapping. The EVA die-cut shoulder straps are minimised yet really comfortable and I've had no aches other than the usual demands on my body over longer days walking.


The back system has been overhauled on the current Mutant model and now has a removable frame. It is sculpted well and remains stiff and stable, cradling my lumbar nicely, with enough venting on hotter days for my liking.

OspMut 5

Overall, I get on well with the Mutant. It isn't perfect, but works well and my criticisms aren't failures, merely niggles. It is lightweight enough for a robust pack and can be stripped to save an additional 380g. It is reasonably weather resistant and very comfortable with higher weights on long days out. Where it wins is it's toughness and comfort.