The Logic Behind Backpacks A backpack should do two things well:\r\n1) Carry everything you need for your adventure; and\r\n2) Ride on your back comfortably.\r\n\r\nIt\'s important to keep number two in perspective. A loaded pack with 30 to 40+ pounds hanging off of your back for hours is not really going to feel comfortable. So let\'s shoot for “reasonably comfortable.\"\r\n\r\nThis Mountain Logic segment dials down on the three main considerations when selecting a pack: size, fit, and features.\r\n\r\n\"When choosing between two packs of different sizes, I pick the larger one. A little extra room in the pack makes it much easier to work out of on the mountain. \" Ed Viesturs