Aimed at those looking for a minimalist yet durable pack for mountain and alpine trips, the Core 35 prioritises functionality over unnecessary features. A low weight, slim compact design and removable features, including all compression straps, make it an ideal pack to climb with. We tested the bag over summer and autumn, both here in the UK and on a trip to the Ecrins, and were suitably impressed.

Who is it for?

The Core 35 is primarily designed as an alpine pack, with a shape and set of features tailored specifically for climbing. But its versatility makes it equally adept for climbing and scrambling in the UK's mountains. For UK winter climbing, I often opt for a larger pack, typically 40L or more and the single ice tool attachment on the Core 35 indicates its intended use outside of winter climbing. Nevertheless, it would be an excellent choice for slightly lighter-equipped UK winter mountaineering days with a single axe.

Its sturdy and straightforward design may also appeal to those seeking a pack that serves them beyond climbing or mountaineering. I've had great satisfaction using this pack for day hillwalking, sport climbing or even an overnight backpacking trip, where I can remove any unnecessary features and rely on its simplicity.

Weight and build quality

There are packs of this size geared towards more ultralight pursuits that are a fair bit lighter, but considering the durability on offer, a weight of 902g on the home scales (Exped quote 880g) is pretty respectable. This can be reduced to just 734g by stripping off all the features.

A 600D polyester outer fabric and 150D lining make the pack feel strong and abrasion-resistant. The inner has a 1200mm and the outer a 3000mm water column for weather resistance, meaning it has performed well in moderate rain but won't remain waterproof in heavy downpours. Both of these fabrics are PU coated which has helped reduce the drying time of the fabric and will also add a little abrasion resistance. Build quality in general is great, with solid and burly finishing.

Fit, comfort and carrying system

Two comfortable padded shoulder straps, an adjustable chest strap, a 50mm webbing waistbelt, and a straightforward padded back panel with an internal removable foam board make up this simple yet effective carrying system. The back length is one size at 48 - 52 cm, so the pack certainly won't be an optimum fit for all users, and it would be best to try it on before buying if you possibly can. I'm about an average height for a man, and for my back length this carrying system has provided the necessary comfort that I need for a day in the mountains outside of carrying particularly heavy loads.

Pushing the remit a bit, I have overloaded this pack to walk in to an alpine refuge for a few days, and decided along the way that I would have preferred a more comfortable and supportive carrying system. You just have to bear in mind that this is a climbing pack, not a trekking pack, and adjust expectations accordingly.

However, the upside to not being a particularly good load carrier is that the Core 35 is great to climb with. I have found it a comfortable alpine pack, both to approach the route and to climb unrestricted in. Due to the soft back panel board, you will want to be attentive when loading with climbing gear and full loads to ensure it's not bulging at the back, but for most mountain days or fast and light climbing hits, this is not a problem with a little care. There also isn't much in the way of fancy venting on the back panel in comparison to many climbing packs, so it does have a tendency to get hot and sweaty. All in all, this has been a comfortable and unrestrictive pack for me, for both walking and climbing.

Features, lid and storage

All of the pack's features - compression straps, waistbelt, attachment accessories - are removable and minimalistic in nature. You get four compression straps, top and bottom on either side, and I've found these to have worked well to reduce the pack's volume or secure a rope on an approach. These are all girth hitched to the bag and easily removable for days when they aren't necessary or to avoid snagging when climbing. The bag has an attachment for one axe, also removable, with two elasticated cinch loops at the upper compression straps to secure an axe although I've found these mostly useful to secure my helmet on the outside of the pack.

The lid is kept simple and fixed to the body of the bag, and because this isn't a floating lid it can feel a little tight on space when the main pack is very full. Whilst climbing with a helmet, the lid's design has meant I have had little restriction when looking up at the climbing ahead.

The lid is attached with a sturdy carabiner to a daisy chain on the body where you can secure other equipment, although I haven't yet needed this. It has a top external pocket and another pocket under the lid for items that aren't accessed as regularly. Internally there is a large flap pocket with a couple of compartments to separate out items. I haven't found this particularly useful when the bag is fully packed as you need to pull out items anyway to access it. But it works well to keep certain pieces of equipment separate and safe from falling out if regularly accessing the main compartment - good at a belay, for example.

Eco credentials

Exped say that the main and liner fabrics are recycled. It's unclear if these are 100% recycled materials so I don't want to draw any conclusions one way or the other. Both these fabrics are also Bluesign certified and PFC-free. On top of this Exped are aiming to be 100% climate neutral by 2024, with more than 70% of their products already climate neutral. All pretty decent.

Conclusion

The stripped-down and durable nature of the Core 35 will appeal to many people who are looking for a great bag that they can take climbing and mountaineering, but which will still be a suitable pack for a hillwalking trip. The tough construction will ensure you can rely on this pack year after year and an entirely removable feature set and slim, compact shape make it great for climbing with. Because of the minimalist design there are some trade-offs when it comes to comfort if carrying heavier loads. But aside from its lack of big-load support this is still a comfortable pack overall - at least if you fit the one-size back length.