Why You Should Always Have More Room Than You Need.
The Karrimor SF brand ambassador, Just, was posed a question recently about rucksack sizes. His answer was inspired by decades of experience.
The question, which appeared on a forum, sounds quite simple. In summary, a guy was looking at two similar packs, one with 40 litre capacity and the other with 45 and he wanted opinions on which he should get.
Many people on the forum insisted that if he could carry everything he needed in a 40 litre pack, then that's what he should get - but Just's answer was different.
Just suggested the larger pack, and for one simple reason - bad packing.
"Go big. Always go big. When you're at home it's quite easy to pack a backpack of any size until it's stretched at the seams. Any compressed gear - like jackets, sleeping bags, and the like - is neatly folded, compressed in the compression bag and stowed. Cooking gear is folded perfectly and stored in its containers. Tents are perfectly rolled and squeezed into their bags. Everything looks perfect - at home. But when you're in the field it's different."
"You need to be able to pack easily in the worst conditions, not just the best."
"In the field - more often than not - you're not packing in ideal conditions. It could be cold, wet, or windy, or any of the above - or all of the above - or you could be in a situation where you need to break camp and move quickly, and recreating those perfectly rolled and compressed bags and sacks just doesn't happen."
"On Arctic expeditions, for example, my sleep system never gets put back in the bag. For a start, stuffing a freezing cold slug into a compression sack when your fingers are so cold that they feel like they're ready to drop off is painful, time consuming and sometimes pretty impossible. My sleep system gets folded in half and laid on the top of the pulk - under the protective cover - because it's easier, it gives it a chance to air, and it remains 'lofted' so it's faster to deploy for use at the next camp. The same goes for my down jacket."
"When I go out in the UK - or anywhere for that matter - I don't use the provided sacks or bags for tents, sleeping bags or most other gear. Often, machines pack new gear into the provided bags, or sometimes it's done by trained and well-practiced humans working with brand new kit in perfect sterile conditions. I ditch those bags and use dry bags in the most appropriate size, which makes packing far easier, and I always use a backpack with a little more capacity than I think I need - it allows for bad packing when I need to, or VERY bad packing if SHTF and I need to decamp in a hurry!"
We asked Just "How much spare capacity do you leave?" and his answer was flexibly vague. "It depends on where I'm going and what I'm doing. In the Arctic, or anywhere with cold and/or wet conditions, or anywhere that I may have to move camp quickly I prefer to have plenty of spare capacity. In warmer environments or more controlled and comfortable locations I still leave spare capacity, but nowhere near as much."
Because that's really the point: you don't pack for the perfect conditions you expect, you pack for the worst conditions you might actually get and when you're cold, wet, tired, in a hurry - or all four - that extra space can suddenly become the most useful space in your pack.