Berghaus Bioflex 45 (2012)

Berghaus has been developing the Bioflex back system for a few years now and for 2012 the system has been revamped to be lighter, but this sack is still on the heavy side at 1620g. However, according to Berghaus the Bioflex system reduces stress, strain and fatigue – so it is possible that this will compensate for the extra weight. The hipbelt rotates around a central pivot to provide unparalleled freedom of movement and comfort, which I particularly liked for scrambling as it felt as if there was no hipbelt to restrict movement. You can also lock off the movement if you prefer a more rigid back system. The body of the Berghaus Bioflex 45 is narrow, making it ideal for scrambling. There are two main compartments, but you can zip away the divider to create one compartment if preferred and still use the external ziparound base entry for stashing wet waterproofs for example. You get mesh wand pockets and compression straps that are useful for stashing trekking poles or ice axes. A second set of compression straps on the base could be used to stash gear. The lid has a very large zipped pocket, which is great for guidebooks, hats, gloves and food.

Weight 1620g
Capacity 45 litres
Compartments 2
External zipped pockets 1
Wand pocket yes
Compression straps yes
Men’s back lengths one size
Women’s back lengths one size



The Berghaus Bioflex 45’s rotating hipbelt provides unparalleled freedom of movement, which compensates for the increased weight of this pack. For general mountain walking, scrambling and easier mountaineering it’s a great all-rounder, and it won our ‘Best in Test’ accolade.

Review by Graham Thompson
First published in Trail magazine October 2012