Sierra Designs Flex Capacitor review: a versatile beast of a backpack

The construction of the Flex Capacitor is much like a duffle bag: a cavernous void to fill up with kit. Straps on the exterior allow loads to be cinched down. (image credit: The Gear Loop)
This allows the pack to be filled and the straps pulled to keep everything from moving about if it isn’t completely full. (image credit: The Gear Loop)
We tested the Flex Capacitor up in the Scotland and Wales and took it on short jaunts and all-day epics, where we were lugging ice axes, crampons and stoves. (image credit: The Gear Loop)
The pack was very stable on both ends of the spectrum and the compression straps provide a handy place to stash an ice axe on long walk-ins. (image credit: The Gear Loop)
The pack also has well-padded shoulder and lumbar straps, which we found comfortable on even the longest days in the hills. (image credit: The Gear Loop)
Both sets of straps have pockets, which we think is a superb feature, with the lumbar pockets proving particularly large and easily accessible on the move. (image credit: The Gear Loop)
We love its unique looks and the duffle bag ability to throw everything into one compartment, but appreciate these talents might not be for everyone. (image credit: The Gear Loop)