Yury wrote:I am not sure I understand why so many people are pissed-off by the idea of a 100 liters pack for Pacific North-West mountaineering school.

For me, it comes down to an ethos thing. Only carry what you absolutely need. 100 liters is unnecessarily large and heavy for any route in the PNW, and gear is like gold fish - they grow to fit the size of their containers. I recall climbing with Colin Haley years ago. We were sitting down, having a break, drinking water. He looks at me and says "EB, your water bottle has a sticker." "So", says I. "But EB, stickers weigh", Colin replied emphatically. I recognize that not everyone climbs technical routes where too much weight means failure, but certainly carrying less weight on the trade routes means more enjoyment.

Yury wrote:What about the following scenario?
You hike to a base camp in light hikers and want to put into your pack (in addition to your personal gear):
- a rope
- a helmet
- a pair of plastic boots
- a bear canister

I suspect that you would need 100+ litrers pack for such hike-in.

Rope, helmet, plastic boots can all go on the outside of the pack. Bear canisters are generally not carried in the PNW, although some heavily used areas (e.g. Boston Basin) they have recently become required due to rodent problems. In the Bugaboos we carried very large packs into base camp, then carried summit packs for the actual climbing. That is the only trip where I felt a giant pack was useful.

Yury wrote:What about the following scenario?
You hike to a base camp in light hikers and want to put into your pack (in addition to your personal gear):
- a rope
- a helmet
- a pair of plastic boots
- a bear canister

I suspect that you would need 100+ litrers pack for such hike-in.

The canister would be solveable, but require me to stuff things in a little different way.

I will do a similiar trek-in now in a few weeks with hiking boots, hiking pants and sports shirt and a 75L. Except for the usual hiking/climbing clothing in the backpack, it will also stuff rope, helmet, +6000m double boots, climbing pants, down sleeping bag (overkill huge -30C/-25F bag), harness, ice axe, crampons, carabiners, poles, sleeping pad + backup sleeping pad, too many chocolate bars, extra camera, goggles, down jacket, expedition gloves+mittens and much more. Everything stuffed inside, except the spare sleeping pad, poles and ice axe on the outside of the backpack. With a warmer and less bulky sleeping bag, my Lundhags 45L would have worked as well, however with the helmet attached outside the bag.

The tricky part was to fit the dual climbing boots inside the bag, I had to test and repack a few times before I found a good way to stuff them. Of course the boots are filled with stuff like socks, mittens etc which I will not need during the trek-in. Same with the helmet, it was placed in the top compartment but inside the helm I've got medkits, hardshells and stuff to fill up the space.

When walking on steep, narrow passages and the wind is stronger, it actually makes a difference with a smaller and more tight backpack attached to the body.

Yury wrote:I am not sure I understand why so many people are pissed-off by the idea of a 100 liters pack for Pacific North-West mountaineering school.

What about the following scenario?
You hike to a base camp in light hikers and want to put into your pack (in addition to your personal gear):
- a rope
- a helmet
- a pair of plastic boots
- a bear canister

I suspect that you would need 100+ litrers pack for such hike-in.

That's everything needed for two 6,000m peaks in Bolivia in a 50L Black Diamond Mission pack. Pick a pack with features that allow for certain gear to be carried/attached outside the pack. Helmet, boots, crampons, ice tool/axe, pickets, shovel, white gas container, two 1 liter water Nalgene bottles + parka are all on the outside of the pack. 60m, 8.5 glacial rope's inside. It was a team of three so I had my own tent, stove & pots which could have been shared and make the pack lighter.