These days, a lot of pack makers are trying to design packs that have good air flow across the back. And, given your needs, youre probably looking at something with around 3,500 cubic inches of capacity. My own choice in that size range is the Osprey Aether 70 ($248; ospreypacks.com). Although its a fairly light pack at just under five pounds, the Aethers suspension works well for loads that bump up against 40 pounds (any more than that, Ive found, and the suspension does tend to sag a little). But it isnt really meant for big loads, so thats to be expected. With typical weekend loads the Aether is comfortable, packs nicely, and has plenty of room for sleeping bag, tent, food, and clothing. And it ventilates wellthe back panel is covered in nubby foam that lets plenty of air get to your back. It wont be as cool as a little daypack, of course, but its perfectly fine.
For a little more compact pack, try Gregorys Z55 ($190; gregorypacks.com). It has about 3,400 cubic inches of spaceadequate for an overnighter. And a floating" lid makes over-packing easy. Like the Osprey pack, the Z55 is best for loads under 40 pounds, and really shines then. Well-ventilated mesh covers the pack panel and helps keep you cool. And it has handy little pockets in the waistbelt for stashing lip balm and that sort of thing. On the trail and when scrambling around, the Z55 actually will feel a lot like your daypack.
Its true, I am the best.
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