Decathlon’s sub-brand Simond has been making winter-ready kit – including sleeping bags – in Chamonix since 1860, and all of that alpine expertise is evident in the excellent Makalu III sleeping bag. It's quite a remarkable feat to only be asking for £290 ($364.66) for EN/ISO temperature ratings of -12C comfort and -19C comfort limit.
No other brand can match Decathlon’s sheer value for money – and, ultimately, here you get top-tier performance for a mid-range price point. It feels like you’re beating the system.
Pros
- Amazing value
- Superb temperature ratings
- Excellent warmth-to-weight ratio
Cons
- Slightly on the heavy side
- Not hydrophobic down
- Restrictive mummy shape
| Price: | £289.99 / $364.71 |
| Temp rating: | -12C comfort, -19C comfort limit |
| Weight: | 1,814g (3.99 lb) |
| Pack size: | 40x27cm |
| Sizes: | Large (one size only) |
| Fill: | 1,100g of 800 fill power duck down |
The impressive warmth of the Makalu III comes courtesy of a whopping 1,100g fill weight of 800 fill power duck down, which is 200-300g more than many other sleeping bags. The down lofts up nicely with a plush, thick feel, and all-round comfort levels are good, although the interior is a tad shiny and plastic-y feeling.
In terms of shape, you get a distinctively alpine, mummy-shaped profile with a central half-zip. The tapered cut is quite narrow and tight, which will polarise opinion: will it be too restrictive or cosily snug?
The Makalu III weighs 1,814g and packs down to 40 x 27cm in the provided stuff sack. There are a few flaws – the down is not hydrophobic, it’s slightly heavy and the eco credentials are not great – but overall this is a top-notch bargain.
Temperature ratings
The Simond Makalu III has the following EN/ISO lab test temperature ratings: comfort -12C, comfort limit -19C and extreme -42C. These are very impressive ratings, offering high levels of warmth for true winter conditions, and you’ll struggle to find comparable temperature ratings anywhere at the same price bracket.
Indeed, the Makalu III provides premium, top-tier temperature ratings, but at a mid-range price point, which is quite remarkable – a real bargain. For example, the Sea to Summit Spark -18C (£625) has a comfort rating of -10C, but it costs more than double the price of the Makalu III.
It’s worth noting, however, that we always take EN/ISO ratings with a pinch of salt, particularly because we tend to feel the cold badly at night – and, perhaps, you should do the same?
All this means is that we’d happily use the Makalu III in sub-zero temperatures down to around -5C, for argument’s sake, or maybe a touch lower, but we wouldn’t fancy pushing things towards the -12C rating. Although you might think differently, of course.
In a wonderfully insightful summary of how to think about the warmth of sleeping bags, Simond also states the following:
“A sleeping bag does not generate heat, but ‘maintains’ heat generated by your body. If you are exhausted and cold and you slip into your freezing and damp sleeping bag, you risk staying cold whatever the sleeping bag's features!
These temperature ratings therefore depend on a person's resistance to the cold (build, fatigue, etc.), on their equipment (mattress that insulates from the ground, etc.), on their clothing (naked, underwear, etc.), and on weather conditions (damp, wind, etc.).”
That’s a good lesson for us all and a sensible way to think about warmth while wild camping.
Insulation type, fill power and fill weight
The Simond Makalu III is filled with 800 fill power duck down, compromising of 90% down and 10% feathers. 800 fill power is a high quality of down, meaning the insulation fluffs up to a thick, plush loft – it works well and feels warm and chunkily-insulated.
Of course, higher grades of down do exist (850, 900 and even up to 1000), but for £290 ($364.66) a fill power of 800 seems fair value.
More impressive, however, is the sheer quantity of down in this sleeping bag. The fill weight is a whopping 1,100g, which is very high – that’s 300g more down than in the Rab Alpine 800, for example, and 200g more than both the Alpkit SkyeHigh 900 and OEX Leviathan EV 900.
This high quantity of down gives this sleeping bag its first-rate warmth and top-tier temperature ratings. How is this achieved? Our best guess is that Decathlon, as a major global retailer, has amazing economies of scale and can therefore offer unrivalled value for money that other brands cannot match.
The down in this sleeping does not, however, have a hydrophobic coating like other down products, such as Nikwax Hydrophobic Down+, so its performance in damp conditions is likely to be compromised. By how much is almost impossible for us to quantify accurately, so ultimately we’d suggest it’s best to do everything in your power to keep the Makalu III dry inside your tent.
All of the down used by Simond has been accredited by the Responsible Down Standard, ensuring it meets important ethical criteria.
Simond explains this process as follows: “Our traceability system allows us to guarantee that the feathers are sourced in line with our commitment to using materials. Our suppliers are committed to only using feathers (sourced in China) from ducks raised for their meat and plucked after slaughter. As a result, we have received the RDS (Down Standard) certification issued by a third-party body.”
Pack size and weight
On our scales, the Simond Makalu III (large) clocks in at a weight of 1,814g, including the stuff sack (61g). We’d class this as mid-weight for a fully-fledged winter sleeping bag: it’s not the lightest, but also far from the heaviest.
Yet, when you take into account the impressive -12C temperature rating, this bag delivers an excellent warmth-to-weight ratio. For comparison, other bags with a similar rating include the Thermarest Saros 0F (2,408g, -10C comfort rating) and the Sea to Summit Spark -18C (1,255g, -10C rating).
The Simond Makalu III compresses down to a size of 40cm x 27cm, when packed inside the included stuff sack. This is an average size for a winter sleeping bag and, while certainly not super-compact, it should fit into a large winter backpack without any difficulty.
The stuff sack is not waterproof, but it has top-entry, drawstring closure and three compression straps for cinching-in the size. Simond says the stuff sack has a 27L capacity.
For storage at home, a larger mesh storage sack (60g) is provided. Using this to store your sleeping bag at home will ensure you won’t ruin the down’s loft by leaving the sleeping bag compressed for months on end.
Materials and sustainability
The outer shell of the Simond Makalu III sleeping bag is made from 100% polyamide with a water-resistant coating. The lining of the sleeping bag is 100% polyester, while the stuff sack is 100% polyamide.
None of these materials are recycled. The insulation is Chinese duck down, which adheres to the Responsible Down Standard. Overall, this bag does not have particularly eco-friendly credentials, but its construction approach is quite common in the industry.
Decathlon and Simond told us: “This sleeping bag is not made with any recycled material. However, the MT900 5C down sleeping bag is filled with recycled down, for example. We intend to expand the recycled down in other products in the near future.”
Size and shape
The Simond Makalu III has a rather pronounced mummy design, with an hour-glass shape and strong taper. The cut is quite narrow and tight, with a distinctive alpine style (Simond calls it a “sarcophagus” shape, which is perhaps telling).
The idea behind this approach is to keep everything snug and cosy, eliminating any ‘dead space’ and cold spots, and maximising the warmth-to-weight ratio. But such a design can polarise opinion. Some will find the shape warm and comfy; others will find it too restrictive, particularly side sleepers who tend to toss and turn at night.
Confusingly, the Makalu III only comes in one size - large. But this size isn’t even that large, it feels more like a medium or a normal, average sized sleeping bag, so it’s best to not get too caught up on the large terminology. We’re 178cm tall and weigh 66kg with a slim build and the fit didn’t feel that roomy.
The Makalu III has the following official dimensions: 210cm long and 80cm wide. Simond states it is suitable for anyone up to 185cm (6ft 1”) tall. If you’re taller, you may need to look elsewhere.
There is no women’s specific version of the Makalu III – instead it’s officially classed by Simond as a unisex product. Two other versions are available, however. The Makalu II (£250) has a -9C comfort rating and weighs 1,400g, while the Makalu I (£200) has a -5C comfort rating and weighs 1,070g.
Features
The main feature to note is the Makalu III’s half-length, central zipper, which is quite a striking design touch. The central zip is backed by a zipper baffle for added warmth, and works two ways (both up and down) for good venting options when required.
The half-length and central location of the zipper may polarise opinion: some may prefer a traditional full-length, side zipper for ease of getting in and out (and better overall venting orientations); but others may love its minimalist approach.
The Makalu III has quite a snug but warm hood, which is adjustable via a drawstring toggle, while the footbox is warm, nicely shaped and well insulated. Internally you get one small Velcro pocket for a headtorch or phone, while the bag’s interior has that slightly shiny’n’slippery feel, but is comfy enough.
Verdict
The Simond Makalu III is an 800 fill power down sleeping bag with an incredible warmth-to-weight ratio at a superb price – but the mummy cut can feel restrictive.
See how it compares to other options in our list of the best winter sleeping bags.
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About the author
James Forrest writes regular features and route guides for Trail and has been one of our main gear testers for the last few years. James is based on the edge of the Lake District so when he isn’t off on his latest crazy adventure or challenge, he’s walking in his local fells.