Jeffrey H. Ryan Hiker Author Photographer Speaker Podcaster Director

FlexCapacitorSometimes old habits die hard.

Case in point: my choice of backpack.

Over the years, I’ve carried more than thirty different packs into the wilderness. Day packs, weekend packs and beasts built for multi-day and even multi week trips. For the past ten years, I used the same pack for trips that lasted 5 to 20 days. I saved up until I could afford a (then) state-of-the-art carbon fiber frame pack. It met my two most important criteria at the time: It needed to carry a lot of gear and it had to weigh less than the pack I had been using for the same purpose.

When a local outfitter was going out of business, I snagged the last one. It was a sweet deal all around. It weighed less than the aluminum frame pack I had been using, had giant capacity and I even saved 40% off the retail price.

A lot has happened in the intervening years. For one, the technology has really changed. Outdoor companies are hyper-focused on creating ultralight gear. Where a through-hiker on the Appalachian Trail used to carry about 40 lbs. of gear, now the average base weight is around 24 lbs.

The idea of packing light isn’t new. (As far back as 1924, the Appalachian Mountain Club’s Arthur Comey was giving a presentation called “Going Light” and wrote a pamphlet about it.) But the means of obtaining a light pack have never been greater. Everything got lighter. Hammocks have become the hottest trend in shelters. Even tents have cool new designs that let you use your hiking poles as tent poles to save weight.

After finishing up my section hike of the AT in 2013, I started looking for ways to lighten my load. (I know. I could have done it sooner. But I wanted to finish with the same old school gear.) I got a new ground pad that shaved off a few pounds and gave that a test drive two weeks ago. That was a nice start. I also bought a new solo shelter with the aforementioned dual purpose pole design.

But the real game changer arrived in the mail today.

With the help of adventurer Andrew Skurka, Sierra Designs rethought pack design. They came up with the aptly named Flex Capacitor pack. This pack solves two significant issues at once.

1. Shedding excess weight

True minimalists want their pack to be basically a sack with straps. Everything else adds weight. I understand the reasoning, but in practice, I can’t go there. I prefer more structure to my packs. It’s how I roll. At 2 lbs. 11 oz. (size M/L) the Flex Capacitor fits my needs perfectly. The “Y-shaped” aluminum tube frame gives it enough integrity to comfortably carry heavy loads and the lumbar and shoulder pads allow air to circulate between my back and the pack. Nice touch.

The designers also shaved weight by streamlining the bells and whistles. My carbon fiber pack had a lot of beefy straps and buckles on it. It also had a detachable hood that doubled as a fanny pack. That was useful at times, but also added more weight than it was worth carrying all the days I didn’t need it. By eliminating the roll-down inner collar, floating hood and buckles and replacing it with a zippered top, Sierra Designs eliminated a lot of top-heavy weight.

2. Solving the capacity dilemma

In the past, I had to choose my pack for a trip based on one thing: How much space I needed on day one. The problem is that your pack needs change as you’re out on the trail. As you eat your food, your pack gets smaller. On day five, you have extra space that you didn’t have on day one. Some pack designers tried to solve this by adding cinch straps to the sides, but they never really worked well. Sierra Designs did it right. Their gusseted bag and cinch strap system lets you adjust the entire pack size to accommodate precisely what you are carrying on a day-to-day basis. Brilliant!

Nice Touches

The Flex Capacitor has some nice extras built in. Two waist belt pockets let you keep a guidebook, map and other essentials in reach without having to take the pack off. A shoulder holster carries a 20 oz. water bottle, bear spray or whatever you prefer. A removable interior pocket is designed to hold a water bladder on short trips (there’s a pass-through hole for the tube as well). Sierra Designs also makes four sizes of waist belts for the pack, so you can be sure of getting the right fit.


When I pulled the Flex Capacitor out of the box, I was immediately struck by how their team created something special. I stood on the scale with it, then stood on the scale with my old pack. The difference was a full 5 lbs. I can’t wait to get this baby out in the field. I am sure I’ve found my new “go to” pack. It will be hard to knock this one off the “favored gear” list. I’ll provide an update when I’ve put it through its paces for a while.

You can check out the pack here. There’s also a nice video walking you through the feature set.

Sierra Designs Flex Capacitor retails for $199.99.

2 Responses

    1. I’ve been carrying a pack belt holster for years and regretted that nobody still made them. It’s so great to be able to check a map or take a photo without taking your pack off.

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