The lightest backpack we've ever used, the Outlier Minimal is surprisingly effective as a barebones commuting gear carrier, but for a pack with almost no features, it's a bit pricy.

At a feathery 162g – a third to a quarter the weight of a similar-sized full-featured rucksack – Outlier's Minimal backpack truly lives up to its name. This is a backpack stripped to essentials: a seam-sealed roll-top compartment, a pair of adjustable straps, and, er, that's it. Bells, frills, whistles, extras, doohickeys and gee-gaws have all been ruthlessly binned in pursuit of what Outlier calls 'the simplest and lightest pack we can make that is still suitable for daily use.'

The secret to both the low weight and high price is an ultra high molecular weight polyethylene laminated fabric that Outlier calls Dyneema, though it seems to be more commonly known as Cuben. (Dyneema is a thread made from a similar material that also happens to have cycling applications: the Dutch team at the Olympics will be using shorts from BioRacer with Dyneema panels for crash-protection. Not that we'd ever wish a crash on anyone, but it'll be interesting to see how it holds up.)

To make the Minimal, Outlier teamed up with Hyperlite Mountain Gear (HMG) http://www.hyperlitemountaingear.com/, who had already figured out how to work with this apparently rather awkward fabric, and a 26-litre bag was born.

Outlier and HMG have done a great job, nailing the shape of both the bag and the stiff, broad shoulder straps so it's comfortable with a commuting load: clothes, books, keys, wallet phone, towel etc. I didn't miss a chest strap, but you could add one to the loops on the shoulder straps if you can't live without it.

I was pleasantly surprised how little I missed having lots of extra pockets and compartments, but maybe that's because I'm stupidly absent-minded. With the Minimal I can't forget which side pocket my wallet's in. It's in the big compartment with everything else. Simple.

The Outlier is also the first rucksack I've ever owned that's got me into a conversation at a set of lights. A young musician (unless the violin case on her back actually contained a sniper rifle or smuggled diamonds) looked at it and asked, 'Is that Cuben fabric? I've got a groundsheet made from that stuff. Best groundsheet I've ever used.'

You want a commuting rucksack and a groundsheet to be extremely waterproof, and the Minimal fits the bill. Our sample arrived just as the weather turned glorious, so we simulated a downpour with ten minutes in the shower. No sign of water inside the bag.

The Outlier brilliantly fulfils its brief of a super-light, rock-bottom-minimal pack, then. It's comfortable for general use and commuting, it's tough and waterproof.

However, it's not cheap. Its $152 price tag translates to around a hundred quid and getting it here from the USA adds another $40 or so. At first sight that's a bit jaw-dropping. Shop around a bit and you could get two Osprey Talon 22s for the same money. But compare with other waterproof packs and they're similarly expensive. They also have full harnesses and padding, but the price you pay for that is weights in the 1-1.5kg range.

The value for money question isn't as clear-cut as it first seems, and the Outlier Minimal is unarguably excellent at fulfilling its design brief. If you like to go light and minimal, you'll probably judge it worth the money.

Verdict

Brilliantly minimal, waterproof and practical for commuting but a little on the pricy side.