Our take If you go through packs like other hikers go through socks, the Alpha AR is for you. It’s made of nylon that’s reinforced with a liquid-crystal polymer (LCP) grid, which increases the tear strength of the material by 30 percent. That means it can take some abuse—squeezing through chimneys, tossing it around at the crag, and sliding through slots. “It got up close and personal with sharp Eastern Sierra granite that would have tattered any other pack, but it came out looking fine,” said one tester after an off-trail, three-day trip to Little Lakes Basin. The LCPs also allow the material to accept longer-lasting coatings (they’re applied at a higher temperature), so Arc’teryx says the Alpha AR’s waterproof PU film should last for years.
The details The lid’s top pocket is roomy enough for a puffy, and a security pocket underneath holds small items. Molded foam shoulder straps, a conically shaped hipbelt, and a plastic framesheet support loads up to 30 pounds.
Trail cred “Even with 25 pounds, I experienced zero sway while bounding down a steep talus field,” our tester said after his trip in the Sierra.