Mountainsmith Mayhem 45

Brand: Mountainsmith

Model: Mayhem 45

Why we like it

It has best-in-class packability, thanks to a super-long, wraparound zipper.


Testers said it cinched the flattest of any pack in the test due to long, wraparound webbing and a large mesh front panel. Smart: Compression straps run under and over the side mesh pockets without blocking water bottles.


A 44-inch zipper peels back the fixed lid and continues all the way down one side of the packbag, splaying it open like a gutted fish. “I could access anything in seconds, top to bottom,” says one tester. Ding: The fixed lid inhibits overstuffing.


“On our third day in Zion National Park, we faced an 8-mile uphill slog, fully packed,” says one 6’4” tester. “The pack rode right on my iliac crest, bearing the brunt of 35 pounds.” He credited the “textbook” load transfer from the light, wire frame. The shoulder straps adjust to torso sizes from 16 to 21 inches, but the framesheet was still too long for some testers; one reported it dug into his lower back.


All the molded backpanel pads are wrapped in airy mesh with pinhead-size holes. While it sits close to the back, our tester “never felt like the pack was creating sweat pools.” The mesh on the hipbelt and shoulder straps has bigger, pencil eraser-size holes.

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