Gear Junkie

Designed for day-long excursions including mountain trekking, hiking, peak bagging, adventure racing, and the like, Gregory’s Z22 manages up to 25 pounds of cargo in its 1,300 cubic inches of capacity.

But what makes the little pack unique is its suspension system, which allows air to circulate behind the back panel, between the pack body and your back, thus keeping you cooler.

Or so the theory goes.

Gregory’s (www.gregorypacks.com) air-flow back panel area props the pack slightly off your back in a manner similar to what Deuter USA and a couple other companies have been doing for years.

But Gregory’s “Jet Stream Dynamic Transfer System” is a bit unique, as it has a tensioning system that stiffens the frame — and offers more support — when more weight is loaded into the pack, doing double duty to keep the pack off your back while also dynamically adjusting with its loaded weight.

The Z22’s harness system is mounted to the main pack on crisscrossing bars. They flex and push out off the pack — thus maintaining the air pocket — when more weight is added.

In my tests, the panel did indeed prop the pack slightly off my back. Its effect is all but unnoticeable while wearing the pack, which is to say the Z22 does its job: It fit fine even with the major new product feature added on.

Some air flows through the opening, keeping you cooler to an extent, though it’s no miracle innovation. I think of the Jet Stream Dynamic Transfer System as just a nice added feature.

But beyond this item, the pack’s clean design has made it my favorite rucksack this spring and summer. It has just one big main pocket with a hydration sleeve; a small zipper pocket on top; and stretchy mesh outer pockets for random extras.

Oh, and there’s the requite hip-belt stash pockets for storing sunscreen, food, salt pills, a compass, and other need-now necessities. (For most adventures, I won’t wear a pack without hip-belt pockets anymore.)

The Z22 goes for $99, which is a fair deal.

For me, the pack carries well and has most of the components I need on a day hike or quick adventure.

Sitting empty, the pack weighs 2 pounds, 10 ounces. That’s a tinge heavy for something this small.

But it comfortably carried about 20 to 25 pounds in my tests, and the suspension system/air-flow area seemed to do its job.

No real complaints here at all.

(Stephen Regenold writes The Gear Junkie column for eight U.S. newspapers; see www.THEGEARJUNKIE.com for video gear reviews, a daily blog, and an archive of Regenold’s work.)