Mammut Ducan Spine 50-60

Our take Mammut has taken the latest step forward in the quest to eliminate backsweat with the Ducan Spine. This pack’s backpanel, a narrow strip of reinforced polyester with a central fiberglass stay, lets air flow freely and avoids the shirt-to-back suction common with full backpanels. “I never felt sweaty, even hiking along the Olympic Coast in 70°F weather—with 90 percent humidity,” one tester says. Two swivels, centered between the shoulder blades and iliac crest, respectively, absorb gait sway while transferring weight to the hips. The result is stabilization of loads up to 40 pounds.

The details Mammut subs external pockets for a detachable hipbelt pouch and mesh pockets on the shoulder straps (some testers missed the extra organization). Expanding the generous roll-top adds 10 liters of capacity. Little misses: The sternum strap is too stretchy to hold tension under a heavy pack, and one tester complained about the squeaky suspension.

$260; 3 lbs. 6 oz. (m’s); one size each, m’s and w’s