Osprey Mutant 28 rucksack review

Osprey Mutant 28 rucksack review

For climbers who will carry their rucksack on longer routes, it makes sense to have a pack that will be as compact and stable as possible while also offering freedom of movement.  However, during the walk in there will also be far more equipment to carry and so then a rucksack that will allow for this too is also needed.  It’s always a trade off.  In recent years many climbers have been choosing a pack that will carry a days kit (albeit with some items like ropes and a helmet to be stored on the outside) but which can then be cinched up as small as possible for the climbs.  The Osprey Mutant 28 seemed to be a great example of this genre and so took one for a test drive.……


The ideal climbing sack will sit high enough to be out of the way of a harness and allow free movement of the hips whilst also being slim enough to allow a free range of arm movement and yet be low enough to allow the head to be tipped back. In reality this usually equates to a fairly boxy shape – exactly like the Mutant.

The ideal climbing sack will be uncluttered but have systems to allow ice axes, skis, bits of climbing hardware, helmets, ropes and maybe a sleeping mat or spare clothing – exactly like the Mutant.

The ideal climbing sack will have a few well placed pockets for small items, guidebooks and will be hydration compatible.  It will also be easy to open and close – exactly like the Mutant.

You get the idea – someone has clearly sat down and carefully thought through all the features a climber needs…..and then come up with good solutions to these requirements.  It is the sort of pack I would have liked to design myself.

In Use

I have used the Mutant for a selection of climbing days.  Some of these were simple single pitch days in the Peak District but, more true to the packs multi pitch capabilities, I’ve used it for multi-pitch climbing in Snowdonia and northern Spain.  I have also used it on a number of hillwalking days and, to get a balanced view on its fit, it has also been used by other climbing friends of both genders.

The carrying comfort of any rucksack should surely always be the primary consideration and I’m happy to report that the Mutant is a great carry.  The back panel is a stiff foam with plastic stiffening sheet and an alloy strip to add rigidity (both are removeable).  This is supported by a simple padded waist belt and shaped padded shoulder straps and a sternum strap.  The rucksack feels great even when fully loaded.  The shoulder straps and back panel are well ventilated and the shoulder straps contour very comfortably around the shoulders.  As mentioned earlier, a number of testers have tried the pack and all have reported a very comfortable fit and carry.  

I tried the rucksack with and without the stiffening sheet and alloy stay.  It works well either way but I definitely found the stiffening system better.  The system offered stability and comfort but also meant I didn’t need to worry that hard items packed towards the back panel would push into my back.  I really like the fit of Osprey packs generally and this one really delivers as well as any I’ve tried.

For a climbing pack, fit then has to extend to consider how well a pack carries when on vertical ground.  Simply put, the Mutant is great again.  The pack sits high on the back and so the harness area isn’t compromised.  It is also low enough at the top so that the head can be tilted back to look upwards even when wearing a helmet.  The shape is quite square at the sides which makes it easy to reach backwards at any angle.  It is really a perfect shape for its intended use. 

Beyond fit, the next most important rucksack factor has to be the features that allow it to carry what you need it to carry.  Firstly, the cuboid shape of the Mutant make it easy to pack and seems, for its 28 litre capacity, to allow a good amount of equipment to be packed.  For example, on a recent trip it was easy to pack a sleeping back at the bottom with space alongside for a Jetboil and Thermarest.  This left plenty of space above for clothing, climbing hardware and food.

Beyond the pack capacity, Osprey have added various attachment points to allow their items to be carried on the outside.  I haven’t yet had chance to try the ski attachments and yet see no reason they won’t work well.  Down each side there’s compression straps which either allow other items to be attached or allows the pack capacity to be reduced when it is part loaded.  They are a standard zig zag style strap system and work as you would expect.

The Mutant closes with a simple zip system.  This makes it easy to get into the pack and creates a very wide opening so it is is simple to get to items inside.  Within the lid there are several pockets.  The top one houses the helmet and rope attachment systems (explained below) although it could still house other items if needed.  Below that is another pocket that is perfect for holding any small items or a guidebook. Lastly, underneath the lid is a mesh pocket that will hold everything else from a wallet to snack bars.  Having all those storage options is a real boon.  

Having a large zip closure like this does mean the pack is never going to be watertight, but almost all rucksacks aren’t watertight anyway – the best way to keep contents dry is to store key items in lightweight dry bags.

As mentioned, the top one of these pockets also contains a strap that can be looped over the pack top to secure a rope or maybe extra clothing.  It secures with a simple alloy ladder lock buckle and works well. Within the same pocket there is an elasticated helmet net that again can be looped over the top.  This again secures with a single buckle and works brilliantly.  A rope can be attached and the helmet still can be looped over the top.  

Beyond that, there are efficient ice axe attachment points and gear holders on either side of the waist belt.  In the back there’s a bladder pocket and plenty of the other little details Ike a sternum strap whistle, key clip and shoulder strap top tighteners.  The Osprey Mutant 28 really is a high performance and comprehensive package.


Osprey only produce packs and travel luggage….and with packs like the Mutant they are clearly at the top of their game.  It is a great climbing pack but will also be a great companion for trekking, mountaineering and scrambling.  I have loved using it and look forward to many more great adventures together. It was praised by all the people that tried it.

There is one other key thing I didn’t mention in this review which is also very significant.  The Mutant happens to also be a great looking rucksack too!  The Mutant retails for £100 and weighs 1000grams and more details, including some great pack videos, can be found on the Osprey website here.

Posted by Paul