Flex Capacitor Backpack


For most backpackers, the Flex Capacitor 40-60 Pack will be ideal for 3-season trips between 3 and 7 days in length. It weighs just 2.5 pounds, but it’s fully featured: durable all-nylon construction, six external pockets, two compression straps, removable hydration sleeve, and a suspension system that was tested with loads up to 70 pounds.

Its most unique feature is a front-side gusset that can be collapsed or expanded to uniformly adjust the pack volume between 40 and 60 liters. Normally, two packs would be necessary to cover this range.

Reader Q: Can a bear canister fit horizontally in the Flex Capacitor?

By Andrew Skurka / January 3, 2018 /

A question from reader, Scott F: To this specific question, my answer is: I don’t know for sure, but it should. I don’t own a Bearikade so I have not tested its compatibility, and I don’t recall any guided clients last year with both a Flex and a Bearikade. However, I know that the BearVault 500…

Preview: Sierra Designs Flex Capacitors 25-40L, 40-60L and 60-75L

By Andrew Skurka / October 29, 2019 /

The original Sierra Designs Flex Capacitor backpack has performed and sold well since it was released three years ago. So Sierra Designs recently expanded the Flex Capacitor series with two new editions, while also updating the original. I was involved with the design and launch of the original Flex Capacitor. But I haven’t been affiliated…