Sierra Designs

Flex Capacitor 40-60

lightweight, adjustable capacity, cost

only two back lengths

Capacity: 60 litres Materials: 100D nylon-poly ripstop/420D nylon Oxford Closure: zipped lid Back system: curved DAC Pressfit aluminium frame, scapular & lumbar pads Back length: 55cm (S/M), 61cm (M/L) Compartments: one Pockets: 1 lid, 2 stretch side, 2 stretch shoulder strap, 2 hipbelt, mesh hydration sleeve Features: side/front compression straps, ice axe/trekking pole straps Maximum recommended load: 23kg sierradesigns.com

This lightweight pack has been a favourite for several years. After much usage, including on my 500-mile/800km Colorado Rockies walk three years ago, it’s still in good condition and should last for many more trips. I chose it for this trip because I like it and I didn’t have any big packs on test. The 60-litre capacity was a bit more than I needed but the pack has front and side compression straps for reducing the volume, and I did use these to stop the load shifting round inside. Having plenty of room also meant I could pack my quilt and insulated jacket loosely, which is better for their longevity than being tightly compressed.

The Flex Capacitor has a stiff frame and well-padded hipbelt. It handles heavy loads well and was very comfortable with the 12kg of this trip. The frame is Y-shaped and curves away from the back so there’s an air gap between the foam scapular and lumbar pads that helps reduce condensation build-up. In the heat this worked well at keeping my back fairly dry.

The big zip opening makes packing the bag and accessing items inside easy, which is good as the pockets are quite small, even though there are six of them.