HikingForclazDown Jacket

Forclaz MT900 -18 down jacket review: reliable warmth at an unbeatable price

A low-budget, high-functioning deep winter down jacket that performs well above its price tag — stripped back, functional, and properly toasty in temperatures well below freezing.

✓  RecommendedForclaz MT900 -18 Down Jacket Weight570 gFill power800-fillPrice£109.99 The good✓  Excellent warmth to weight ratio
✓  Very packable — packs into its own pocket
✓  Soft outer material
✓  Reinforced shoulders and cuffs
✓  Pit zips for heat regulation
✓  Responsibly sourced down
✓  Decathlon 2-year warranty
✓  Incredible value for money
The not-so-good✗  Fairly fragile 15-denier material
✗  Not as stylish as premium alternatives
✗  Not waterproof — needs a shell in rain
Check price at Decathlon →

At a glance

Overview

The Forclaz MT900 -18 down jacket is a lightweight and super warm puffer jacket from French sports powerhouse Decathlon. The thickest of the Forclaz down range, it promises to keep you warm in temperatures between -5 and -18°C (with appropriate layers), while still being ultra-packable and decidedly portable. And all for £109.99.

Here at GBAC, we have long been big fans of Decathlon. The value for money on all of the lines we have tested to date has been consistently industry-leading. And while that is not to say you should expect the same quality and level of detail as you might get from more premium brands, their kit is just as fit for purpose while sometimes being more than half the price.

Created by Forclaz, Decathlon’s in-house dedicated hiking brand, the MT900 jacket has been designed to be a no-frills warm layer that you can throw over when taking a break on winter adventures. In seriously low temperatures (think -10°C or lower), you could also wear it on the move, but it would be a rare day in the UK when you would wear this while hiking. Despite its no-frills design, the jacket is still competitively lightweight, coming in at an impressive 570 g for the large size. This makes it almost 200 grams lighter than the Mountain Equipment Lightline — a down jacket we rate very highly — and a mere 100 grams heavier than the Patagonia Fitz Roy down hoody, a jacket that costs almost four times as much.

Coming with glued seams across the front, back and arms of the jacket, the MT900 promises to lock in warmth and keep drafts out by hermetically sealing you inside. It also comes with a cosy hood that fits snug to your head, two large handwarmer pockets, pockets inside for stashing gloves and maps while you move, and — something we had not seen before — lengthy pit zips along both sides of the jacket that allow you to regulate heat when wearing the coat on high-output activities. What is more, the jacket can be cinched tight around your hips and face to lock in even more heat, and the whole thing stashes back down into its pocket. When packed away, the MT900 is about the same size as a 1-litre Nalgene bottle, which is smaller than the ME Lightline and just slightly bigger than the Patagonia Fitz Roy.

Inside the jacket, the insulation is provided by a blend of 85% duck down and 15% feathers, with a fill power of 800. As with all of Decathlon’s down products, the down is traceable and responsibly sourced.

How we tested

To test the Forclaz MT900 -18 down jacket, we took it out on numerous escapades up and down the UK through the autumn and winter of 2023. We used it on a rainy walk in temperatures just above freezing in the Chiltern Hills, took it on a wet and windy backpacking trip across Dartmoor, and had it on during a serious cold snap during a two-night wild camping trip in the western edge of Bannau Brycheiniog National Park (the Brecon Beacons). For reference, we used the jacket in conjunction with the mid-range Mountain Equipment Lightline and the ultra high-end The North Face Pumori Down Parka, all to understand the performance of three jackets from very different price points.

Features and performance

Build quality and durability

Made out of a 15-denier polyamide fabric, the Forclaz MT900 -18 down jacket is soft to the touch and comfortable to wear. Naturally, however, due to the thin materials used (in order to maximise packability), the jacket feels quite delicate. You would not want to wear this charging through any gorse, nor would you want to fight your way through a dense forest in it. That said, along the shoulders and around the wrists, the designers at Forclaz have added additional inserts that protect these harder-working parts against the inevitable wear and tear. Along the shoulders, the thicker lining prevents the straps of a backpack from wearing into the material over time, as well as providing some added weather protection. The inserts around the wrists prevent snagging when you plunge your hands in and out of gloves and pockets on cold winter adventures.

On the subject of weather protection: the Forclaz MT900 -18 is not waterproof. Decathlon labels the material ‘water repellent’, but it is not designed to be fully waterproof — doing so would result in a decidedly less packable jacket, which is one of the main selling points of the MT900. You should always ensure you have a waterproof shell handy whenever you are wearing it, as down loses its ability to keep you warm the second it gets wet.

“When you consider the warmth, weight and packability you get for £109.99 — which are the only three factors that really count for jackets like these — we can’t think of a single alternative jacket that rivals the Forclaz MT900 -18.”

Warmth

When it comes to warmth, we found the Forclaz MT900 to be incredibly impressive — easily market-leading at this price point. The close fit and the ability to cinch everything down meant that we felt just as warm in this jacket as we felt in the Mountain Equipment Lightline and The North Face Pumori. Now, that is not a scientific statement by any means — it merely ‘felt’ like the MT900 did an equally good job as the other two jackets in the same conditions. But that makes it no less impressive, especially considering the price: when bought brand new from Decathlon, the MT900 -18 costs £109.99. That is half the price of the Mountain Equipment Lightline, one-third the price of a Rab Neutrino Pro, or one-fifth the price of The North Face Pumori Down Parka. So, when you consider the warmth, weight and packability you get for that money — which, let’s be honest, are the only three factors that really count for jackets like these — we cannot think of a single alternative jacket that rivals the Forclaz MT900 -18.

The Forclaz MT900 -18 on a brutally chilly wild camp in the western Brecon Beacons.

Looks

One final thing worth mentioning is the look of the jacket. While this should not really matter — especially when you use it for the things it was designed for — it will always play a role. After all, you will probably only be using this for deep winter wild camps a handful of times a year in the UK. The rest of the time, you will end up wearing it around town, walking the dog, or on chilly walks to the pub. And for us, we are simply not huge fans of how it looks. In the next iteration, we would like to see Decathlon redesign it so you would confidently wear it when not in the hills — but that is a super minor gripe and does not negate the otherwise excellent job this jacket does at keeping you toasty warm.

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Our verdictThe best-value deep-winter down jacket on the market right now.Overall, we really rate the Forclaz MT900 -18 jacket. It is effortlessly functional, toasty warm and, weighing only 570 g, barely noticeable in your pack. It comes with some excellent features, contains responsibly sourced down and comes with Decathlon’s generous 2-year warranty as standard.The thing that continues to impress us most of all, however, is the price. At £109.99, we do not think there is a better value puffer jacket out there right now — especially when you consider the all-important factors of warmth, packability and weight. Half the price of the Mountain Equipment Lightline, one-third the price of the Rab Neutrino Pro, one-fifth the price of The North Face Pumori. And yet, in our testing, it kept us just as warm.Buy the Forclaz MT900 -18 at Decathlon →

FAQs

How warm is the Forclaz MT900 -18 down jacket?Very warm — as warm as more expensive jackets from more premium brands in our testing. The close fit and the ability to cinch everything down tight made it feel comparable to the Mountain Equipment Lightline and The North Face Pumori in the same conditions.

What activities is the Forclaz MT900 -18 suitable for?Wild camping and hiking in freezing-cold conditions. You would not want to wear it during high-output activities like hillwalking or mountaineering, but it should go on the moment you stop. In temperatures of -10°C or lower, you could wear it on the move.

How waterproof is the Forclaz MT900 -18?Not waterproof at all. Decathlon list it as water resistant — the DWR coating will stop water penetrating for a short time in light rain, but for any sustained rainfall you will need a waterproof shell over the top. Down loses its insulating properties the moment it gets wet.

Is the Forclaz MT900 -18 worth the money?Yes. At £109.99 from Decathlon, we do not think there is a better value down jacket out there right now, especially when you consider the all-important factors of warmth, packability and weight.

How durable is the Forclaz MT900 -18?The lightweight 15-denier polyamide fabric is not particularly durable. Reinforced patches on the shoulders and wrists protect those areas, but the rest of the jacket could be easily snagged on rough terrain. Treat it accordingly — wear a hardshell over the top in technical ground.