Lightweight and adaptable it can be stripped down, removing the hipbelt padding, frame strut and top lid, or left as off-the-shelf to swallow a long weekend's essentials for a multi-day climb.
What Mammut say:
Trion Light all-year round backpacks are surprisingly light and versatile. The 38+ is our multi-purpose model: Its total back length of only 55 cm and its removable top flap give you great freedom of movement when climbing. In case you need even more flexibility, you can easily remove the T-Frame „Remove & Climb” frame strut. When you also remove the paddings of the hip belt and the flap you get a super light backpack that weighs in at only 630 g. On a ski tour, the very accessible front compartment is perfect for stowing your safety gear.
Suspension system: MOTION T Frame™
Weight [g]: 850
T-frame, "Remove & Climb" frame strut, can be easily removed for enhanced climbing performance
Good back ventilation due to the 3-D EVA foam with air channels
Very light, highly breathable EVA shoulder padding
Length-adjustable, detachable hip belt padding
Height-adjustable detachable flap with internal and exterior pockets
Back length M, 46 cm, perfect for climbing
Large front compartment for safety equipment to allow rapid access
Reinforced side ski attachment
2 ultra-stable ice axe carriers
Compression straps can be tensioned at the side or at the front
Hydration system compatible
Rope fixing strap under the flap
On test with MyOutdoors:
I've been using the Trion for a few months now and it's been an instant hit in my kit list. As we've entered the warmer months the overall lightweight construction and minimal padding have proved very comfortable on longer days in the hills. There are much stronger packs out there for hauling gear in, but the Trion makes up for that in comfort and load transference. The EVA shoulder straps have a good amount of give and owing to a thin construction, can be cinched in at the chest strap tightly with no discomfort for me. The waist belt is also thin, but wide. Once adjusted to size correctly it provides good support, is non restrictive and is, of course, harness compatible. Crucially for a climbing pack, I felt reassuringly 'bolted into' the Trion, while not suffering from any chest or breathing constrictions. I would recommend a comfortable upper limit of 12-14kg as a maximum load. Beyond that you may be looking for more support.
Overall, the capacity is a generous 38 litres +, enhanced by the roll top enclosure, back pocket and detachable lid. The lid has a mesh pocket inside, with a key-clip, plus a decent sized tapering pocket on the top. A neat feature is that the lid re-attaches into the back of the pack on small eyelets, so you can continue to access the pockets for essentials. Once removed, you can then keep adding to the main compartment and roll it closed, ready to stow a rope or helmet on the top. There remains good head clearance when looking up in a helmet. Like many dedicated climbing packs, the Trion can be stripped back, removing the lid, the motion-T frame in the back-piece and even the hip-belt, to weigh in at 630g. In this mode it moulds well to my back, although I prefer the hip belt attached for the extra security.
The pack fabric isn't waterproof but the roll top will keep snow out well. So far the 100 denier fabric, reinforced at the base with a 210 denier ripstop nylon is proving hard-wearing but reassuringly lightweight.
Other main features are the stowing systems and sleeve pocket on the rear of the pack. Tipped by Mammut as ideal for safety gear, the rear pocket does indeed fit a detachable snow shovel and other kit in easily. The pocket is also good for jackets and other kit to grab, removing the need to keep unrolling the top through a days climbing, walking or in a mountain emergency.
The compression straps team up with ski straps at the base, to facilitate ski touring trips, or can be used for storing ropes draped over the top of the pack.
The water bladder pocket is generous enough for 2 litres and the exit port is on the right. Some people prefer a central option to choose a side, but I don't feel that's too important.
Lastly, the 'ultra-stable' ice axe stowage is excellent. Quick and easy to store or deploy a variety of axe shapes, either crossing over technical axes, longer axes for glacier work, or ski and walking poles, they work simply and well.
The only minor niggles I've had so far with the Trion has been the eyelets and hook system for the lid are fiddly and small. Clearly they save on weight and make the construction neater, but probably aren't possible to remove or fasten with gloves on. They're ok with a bit of practice though. Secondly, the shoulder straps squeak a fair bit. This isn't a disaster, although a bit distracting and could be unique to my pack.
The Trion Light 38 is a well thought out pack by Mammut, fitted out to be fully functional in alpine environments. It is also versatile enough to use as a trekking pack, suiting a fast and light approach to summit bagging and scrambling. If like me, you prefer a shorter back length and manoeuvrability of your head, then the Trion may suit.
A good compromise between being lightweight and durable enough to be abused has been found. There is enough give in the ripstop nylon to allow it to be fairly stuffed with gear, without feeling like you're going to pop some stitching. It has a good looking design and remains unfussy and very functional.