Fjallraven Keb Eco-Shell Trousers review: Waterproof, windproof, worth £400?

This September, I got shipped out to the Lake District to walk the Fjallraven Classic, a 50km hike which runs through deep valleys and over boggy fells. Facing rain and hail predictions, the Fjallraven team assured me that all I needed to stay dry and warm was a pair of Keb Eco-Shell Trousers. Nervously, I accepted their advice.

For context, around 15 years ago, Swedish outdoor gear producer Fjallraven and waterproof membrane giant Gore-Tex parted ways.

Gore-Tex membranes were unbeatable for waterproofing and breathability, but they relied on PFAS chemicals and DWR coatings that were harmful to the environment and non-recyclable.

In line with its environmental pledge, Fjallraven stopped using Gore-Tex and began developing its own waterproof fabric.

That fabric is now Eco-Shell: a three-layer material made from recycled polyester, treated with a PFAS-free, PFC-free durable water-repellent coating. We’ve seen Eco-Shell used in jackets for a few years, and frankly, we've never been especially impressed,

But after a week of hiking through a wet and windy Lake District, with these being my only waterproof hiking trousers, I finally saw this material (and Fjallraven's design philosophy) shine.

Waterproofing and breathability

On paper, the Keb Eco-Shell trousers are top tier: a 30,000mm hydrostatic head and breathability of 26,000g/m²/24h. That puts them ahead of even the Arc’teryx Beta trousers, long our benchmark for the best waterproof hiking trousers.

They’re also completely windproof, so you can skip an insulating layer beneath in all but the coldest conditions. I ended up pairing them with hiking shorts!

Price, however, raises the stakes. At around £420 (about $450), these are among the most expensive walking trousers on the market. Few trousers make this many claims, though, and in use they justify much of the cost.

During my multi-day hike in relentless rain and occasional hail, they stayed bone dry and offered noticeable wind protection, adding warmth without bulk. Crucially, they remained genuinely breathable: even on 20-mile days I never noticed clamminess or sweat build-up.

The fabric lacks any wicking treatment, but it’s permeable enough that moisture simply evaporates, keeping the inside dry and airy. I'm genuinely amazed by this – so many waterproof trousers get wet and sticky on the inside, but the Kebs were comfy even against my bare skin.

Fit and freedom of movement

The Eco-Shell fabric itself isn’t especially stretchy (despite Fjallraven claiming it is), but the cut makes up for it. Pre-shaped knees and a gusseted rear provide excellent freedom of movement whether you’re scrambling, climbing, or power-hiking.

They never caught on knees, snagged on boots, or restricted stride length. Which, you might think is the bare minimum, but try a few other pairs of waterproofs and come back to me then.

Despite being designed as overtrousers, they’re comfortable next to bare skin. The interior fabric is softer and lighter than you might expect from a three-layer hardshell, and every seam is thoroughly taped for full waterproof protection.

Sizing runs from XS to XXXL without numbered waist options, but the integrated belt and dual Velcro waist adjusters give plenty of fit flexibility. The belt sits flat under a backpack hipbelt or climbing harness, though it’s fiddly to undo with gloves, so set it before heading out.

Ventilation and access

Full-length two-way side zips make these trousers easy to get on and off over big boots or crampons, and they double as ventilation.

You can open them from the top or bottom for as much airflow as you like, while an Aquaguard storm flap keeps rain out. The chunky YKK zippers have fabric pulls for glove-friendly operation, and the wide Velcro hip tabs allow the opening to expand so you can easily grab these and throw them on when the weather gets dicey.

At the cuffs, a single durable popper secures the hem, which can then be tightened or loosened with an elastic drawcord. Adjustment is simple, with enough range to accommodate anything from waterproof trail running shoes to bulky winter walking boots. Reinforced Cordura panels on the lower legs add abrasion resistance against rocks, skis, or crampons.

Pockets and features

Unlike many waterproof trousers, the Keb Eco-Shell includes two hand pockets where you’d expect them. They’re not huge but will hold a smartphone or a folded map. The mesh pocket linings are lightweight, and the AquaGuard zips are topped with a small fabric tab to seal out water.

Between the zipped opening and loose-woven mesh interior, I was nervous to keep my phone in these pockets through heavy rain, but it stayed dry without issue. Though large phones may press against your hip crease during high steps, so don't load these pockets up.

Belt loops are double-layered: the integrated belt runs through the inner loop, while the outer can take braces or a climbing harness if you want extra security. A small hanging tab on the waistband makes it easy to dry the trousers after a wet day.

Durability and comfort

Fjallraven claims excellent durability, with Cordura reinforcements around the leg endings and inside cuffs. Plus the three layer main material also holding up in tough conditions. I can't forget the £400+ price tag, so my expectations are sky high when it comes to the longevity of these things.

After their first 50 (with a few thousand metres of ascent, rocky scrambles, and technical descents) the trousers show zero wear – thank god. I did notice a single loose polyester thread around the hem, which is disappointing at this price but hardly catastrophic.

Overall construction is excellent. The minimalist design and taped seams really do make these feel like a proper shell, and every feature feels carefully considered. From the soft inner lining to the articulated knees, the design is precise and performs excellently.

Verdict

The Fjallraven Keb Eco-Shell Trousers live up to their lofty promises. They deliver outstanding waterproofing, real breathability, and reliable wind protection, all in a comfortable, well-cut design packed with thoughtful details.

They’re highly adjustable yet easy to use, with full-length zips, an integrated belt, and practical pockets.

They’re expensive, no question. At over £400 I'd recommend these to proper mountaineers only. Or, you could justify the purchase by leaning into their do-it-all, year-round approach and literally use them for everything. Dog walks, alpine ascents, birthday parties. They'll work.

About the author

Milo Wilson is one of our resident testers whose fear of wet legs makes him an ideal candidate to review waterproof trousers. He spends his time yomping around the military south, destroying trail running shoes on army training routes whenever he can get away from his desk.

Once a month or so, he finds an excuse to jet off to the Lakes, where he tests all his new waterproof gear in some real harsh conditions.