About a year ago I went off to do a variant of the Haute Route. I choose the Mammut Trion Light 28 as my sack. The weather was stable but cold all week so I had a reasonable amount of clothing plus one of the ropes so whilst 28 Litres was enough, it was a bit of a squash for all my kit and I was a bit sick of doing it by the end of the trip. In the photo above I’ve got my down jacket and primaloft shorts on, my shell is on the side but the pack still looks quite full!
On my return I had a look at the Trion Light 38. Essentially it’s the same roll top design as the 28 but with a removable lid stuck over the top (not immediately obvious from the product images from Mammut) and a flat pocket on the front for your snow safety kit.
The lid can be left over the top, hung from the inside of the pack as an organiser pocket or left at home. In this inside pocket configuration a minor issue I had with the 28 was solved which was that it lacked a handy spot inside for your little bits and pieces inside when touring. On the trip I just used a drybag as the last thing into the pack but nice to have a hanging pocket.
The extra 10 Litres was also very welcome but not too much space to be needlessly filled. Both packs are very comfortable and compress down well. Both packs also feature a central aluminium stay which is removable. I have tended to keep it in place for the 38 but remove it from the 28. Both have good tool and ski carry straps and even the larger pack is well under a kilo in weight, an important and often overlooked consideration.
Since the 28 does reduce in volume nicely I realised that all my pack needs in life were met by these two packs, even the everyday tasks of gym and swimming pool. I have swapped back and forth between these packs for about a year now and both are wearing very well for lightweight packs, although the 28 is currently the most grubby! The 38 is definitely my first choice for alpine and touring trips whilst the 28 is great for cragging , summer use and as a small daypack.