The obvious, but unhelpful, answer is – it depends on what you want to carry.
The picture above is my pack from a trip up Mt Baldy in California in April 2017. It was a late season climb, mostly dry rock and trails with good, stable weather, but some hard snow on the summit (10,064ft) and some potentially sketchy icy bits on the Devil’s Backbone on the way up. I knew the route and was confident in the weather, so I didn’t feel the need to take lots of extra clothing and gear – just a light fleece, first aid, food and drinks; the crampons and axe were necessary, the rope was just in case. In this instance, 30L was more plenty.
But for a big day out, like February or March on Ben Nevis, I also want to take a belay jacket, a spare warm layer, 2 or 3 pairs of gloves, 2 x 750ml flasks, lots of food, goggles, a helmet and a bigger first aid kit. For that, I’d take my Mammut Trion Nordwand 38L. Any smaller would be a pain to squeeze everything in, but bigger isn’t necessary – although if I wanted to carry more climbing gear than a couple of slings and an alpine harness it might start getting tight in there… Specific to the Nordwand 38L, the rolltop opening helps get big stuff in and out easily and the movable lid gives me a bit of extra flexibility on capacity.
But for a big day out, like February or March on Ben Nevis, I also want to take a belay jacket, a spare warm layer, 2 or 3 pairs of gloves, 2 x 750ml flasks, lots of food, goggles, a helmet and a bigger first aid kit. For that, I’d take my Mammut Trion Nordwand 38L. Any smaller would be a pain to squeeze everything in, but bigger isn’t necessary – although if I wanted to carry more climbing gear than a couple of slings and an alpine harness it might start getting tight in there… Specific to the Nordwand 38L, the rolltop opening helps get big stuff in and out easily and the movable lid gives me a bit of extra flexibility on capacity.
Originally I thought I could get away with my 30L pack for more serious winter days, but I was wrong. I was originally advised to look at 35-45L, but I like feeling like I have the right stuff with me, so I pack I bit heavier than I could probably get away with. For me, 38L feels perfect.
