Mammut Trion Pro 50 + 7 Review

The Mammut Trion Pro is a fully featured mountaineering pack, complete with an external zippered organization pocket, which can hold your avalanche rescue gear. This is a decent all-around pack that can handle most mountain sports. It is plenty durable for anything you can throw at it, but it is not comfortable enough to earn its keep on most of our adventures.

Performance Comparison

Weight-To-Volume Ratio

The Trion had a rough go again in this review. The pack has a lot of features, making it very versatile, but adding quite a bit of weight. The Trion has an extra zippered sleeve in the front for quick access to slim and lightweight gear like your avalanche rescue kit, and a zippered back panel which is a favorite feature in snow-optimized packs.

The Trion Pro is not designed to expand very much to accommodate extra gear. This seems like a stylistic difference between American style mountain adventures and European (or Alps) style mountain excursions. In the U.S., we often have long approaches to camp, where we drop our tent and cook set, then slim down our pack and climb from there. In a lot of Alps climbing, you may be staying in a hut, and therefore don't need all the heavy, bulky camping gear.

Both modes are awesome, obviously, but different. And as such, this Swiss-designed mountaineering pack does not expand as much as we would like at times. The collar doesn't provide much upward expansion, and the side straps barely extend enough to hold a short foam pad. (There are two extension straps included to accommodate larger pads.)

The flip side of this minimal expansion is that it forces you to pack well to get your whole kit inside the backpack. We often find that if we carry a 50L pack instead of a 40L pack, the load seems to expand to fill the extra 10L. Likely, we are sloppier in our packing because we know we don't have to be such Tetris masters to get all our gear inside. So we do like that we are obliged to be good packers and get our kit neatly inside the Trion Pro.

The Trion Pro is not light. It weighs just over 4 lbs, and we were only able to get 45L of usable space in our Volume Test. This is a fully featured pack, which is best suited to snow sports. Compared to similar ski-related models, this pack's seemingly heavy weight-to-volume ratio looks much more reasonable. All this is to say, if you're looking for a great ski pack, don't shy away from this pack. It is not the ideal mountaineering generalist, but it might be a good fit if you're looking for a snow-optimized backpack.

Comfort

The Trion Pro still took a dive in the comfort tests this year. No matter how we packed, fit, and adjusted it, it would pull back on our shoulders. Packing it with our winter kit, which is more bulky and puffy than it is heavy, improved carrying comfort. There was a critical point around 25-30 lbs where carrying comfort started to diminish.

The back panel did not sit flush on our back like the models that topped this category. We much preferred the flat back panels featured in the Hyperlite Mountain Gear 3400 Ice Pack, and in the award-winning Arc'teryx Alpha FL 45, as well as our other Top Pick, the Patagonia Ascensionist. The knobby protrusions on the back panel felt uncomfortable. They are not necessarily worth the increased breathability and airflow created by the spaces between them, partially because this is a snow-optimized pack and a sweaty back is often less of a concern in winter-related backpacks.

The hip belt is quite comfortable on this pack, with thinner but firm, supportive padding it allowed a good range of motion. And it is removable for stripping weight off the pack for a summit push. Since this pack is on the heavier side, we did not appreciate this feature. (We appreciate it more on lightweight packs.) The pack itself adds a fair amount of weight before you've even put any gear inside of it. If you want a pack that strips down, or better yet, is so lightweight and comfortable you don't need to, check out either the Osprey Mutant or the Arc'teryx Alpha FL.

The foam on the shoulder pads is also nice and firm, which is ultimately more supportive. We tend to prefer even firmer foam and a little more width to spread out the load, but this can be a matter of personal preference.

Durability

The Trion is made of extremely durable fabrics, earning an above average score in this metric — its strongest score in the review. It is a very well made backpack, holding up the strong Mammut reputation for durable, long-lasting, and typically high-quality gear. This year, the durable nylon shell is rated as nearly waterproof, supporting a 5,000mm water column. This means it will shed rain and snow, but if you set it down in a puddle, it will wet out where it pushes up against a wet surface.

Packs are all made of relatively durable fabrics these days, with a few stand-out exceptions. (Cuben fiber, for example, is particularly prone to holes when it makes contact with sharp or abrasive objects.) For this reason, we also focus our attention on any stress points on the packs or places of unusual wear.

The Trion has such short side straps that not only are they nearly impossible to use, they also wrenched on the seam when attaching ordinary objects such as a 3/4 length foam sleeping pad. Fortunately, Mammut includes extension straps you can clip on, but we found this to be a somewhat cumbersome fix, which also adds more weight than just adding a few more inches to the straps already sewn on the pack.

Versatility

When we put all our observations together and considered that this is a ski-optimized pack that hails from Switzerland, a much more clear picture came into view: this is a pack designed for hut-to-hut style trips. If you travel hut to hut, you won't need a foam pad, so the short side straps won't be an issue there. (We think the foam is a good item to have in case of emergencies or accidents.) Two extension straps can be added to accommodate a full-length foam pad or larger/bulky items. However, we found this to be a cumbersome fix and would have preferred a few more inches on the side straps.

The Trion Pro is very sleek and compact for its volume. It keeps straps contained with elastic loops and sharp objects close and protected. This is great for hopping on crowded trams or managing bustling mountain areas, which are common in the Alps. For a genuinely versatile pack, check out our Editor's Choice winner, the Osprey Mutant 38. Or, if you need a highly versatile mountaineering pack with more volume, you might like the Black Diamond Mission 75.

While this pack scored below average for versatility, we considered its specificity to be a strength. If you're looking for a svelte ski mountaineering pack, this is a good option. Smaller athletes will likely feel this pack is a bit large to be comfortable when it is packed full. But so long as the comfort issues aren't a deal breaker for you, or if it fits you and your equipment better than our testers, this may still be a great pack for you.

Features

If you're after a full-featured backcountry ski pack, this is a decent one. It has some excellent features for the snow enthusiast, and especially those venturing out on hut trips. As such, it got an average score for features. If you want a ski pack, the features are great; however, there were some redundancies that we didn't like and which add a little weight here and there, which adds up.

We like the gear loops on the (removable) hip belt. We did not find it useful to remove the hip belt on this pack, as it is not our go-to for fast-and-light missions. The pack itself is heavy enough due to the burly materials and extra features (like double ice axe attachments and the external zippered compartment) that we wanted the support of that very comfortable hip belt even on our summit pushes. This hip belt also cinches inward with a reversing buckle system. We're not overly fond of this design as it adds extra strap material and therefore extra weight and wind-flapping potential.

Using the following simple technique, we can get our packs just as snug around our hips with a traditional strap and buckle design. Put your left hand on your left hip, holding the hip belt in place, then grab the same-side strap with your right hand. As you push on your left hip, pull that strap out and left. Repeat on the opposite side.

There is a strap under the lid of the pack to secure a rope, a very useful climbing specific feature. And we liked the two zippered compartments on the lid, just the right size for useful items but not big enough to tempt you to weigh the lid down. However, the geometry seemed off, as we often had trouble lining up the lid. It would get in the way of the load lifter straps on the shoulders, or otherwise be difficult to center on top of the main compartment.

We think the redundant ice tool/axe attachments are excessive and add unnecessary weight. In trying to make this pack a generalist, Mammut has detracted from the simplicity of a good mountaineering pack and added weight. It does, however, mean it will likely work as your only pack, it will just be mildly annoying for every activity. To attach your pick-of-choice, you can flip and fold an axe or two onto the pack using the ice axe loop, or you can fasten two ice tools through the buckle system. We're not sure why there are four ways to attach tools when you can only carry two at a time.

Overall, there are a few quirks in the design features on this pack. We think things could be streamlined to shave a little weight and make things simpler.

Best Applications

This pack is best suited to hut-to-hut backcountry ski tours. It is voluminous enough to carry some bivy gear as well. It is heavier than many packs in this review but on par with other snow-optimized backpacks.

Value

Mammut tends to be on the pricier side of the gear, but this pack offers a good value considering the quality materials and durable components. This pack will work for almost any mountain activity, though they list it for Hiking and Mountaineering. We think it makes more sense if you're traveling on snow, but in general, it is a pack full of compromises. While it will work for a range of activities, we think there are a number of frustrating distractions and detractions from the smooth operation of the pack.

Conclusion

During this review, this pack didn't shake out as a versatile mountaineering tool, but it may still be an excellent pack if you're looking for a solid ski or split board mountaineering pack. It is decent enough to work for a variety of mountain adventures, but if you're serious about your mountain sport of choice, we think it's worth it to get a pack that better suits the specific needs of your activity.