Jack Wolfskin Smoozip -7 Sleeping Bag – Review
The Smoozip -7 sleeping bag from Jack Wolfskin offers comfort down to -1C, has an ergonomic ‘one movement’ zip and is filled with 1200g of snuggly warm insulation. That’s the feature set, but how does it perform?
With a suggested comfort rating of -1°C, it is marketed as a four season bag and Jack Wolfskin believe it’ll be just about warm enough all the way down to -7°C.
For men, the bag comes in ‘Dark Steel’, which is almost entirely grey on the outside, and red on the inside. A women’s version is available in a slightly different colour, is 20cm shorter and 200g lighter. A pencil line tracing the zip runs across the body of the bag in an arc which helps to break up the colour somewhat. The finish is completely smooth because there are no baffles present, due to the synthetic fill of the bag.
Jack Wolfskin say the zip can be opened or closed in ‘one smooth movement’ and they have also reflected this in the product name. I found the zip action to be very smooth – more so than many others – but as for doing up in one action? No. I put this to the test by trying to do it up in one go and never succeeded. I also tried to do it while I was out of the bag, with the benefit of two properly free hands and still couldn’t manage it. Just like with any sleeping bag, if a bit of material overhangs the zip even slightly, it will catch; and that’s no different with the Smoozip -7.
Fortunately, the zip doesn’t catch too often, maybe once or twice along its length, which is significantly better than other bags I have used. Endless zip catching is one of the most annoying things I’ve encountered when camping. The other thing to note here, is the zip length. Many bags have a half zip, or even none at all. This has a full length zip which not only extends to the bottom of the sleeping bag, but also around the base too.
At the end of the zip, there is a secondary puller, which means you can get some airflow through the bag on a warmer night. Instead of the zips running head-to-head, they run bottom-to-bottom, so the zip will be split at both ends if you choose to undo it, rather than having an gap somewhere along the length of it. To clarify: the opening will always begin at the base and/or the top – you cannot position a small opening wherever you want to.
Not only does the zip split at both ends, but you can also undo it entirely to open the bag out. What this feature is for, I’m really not sure. Airing the bag after a trip? That’s the only reason I can think of. Jack Wolfskin chose to give the zip an ‘ergonomic’ shape down the bag, so instead of running down one side, it runs a third of the way down the side, before curving across the bag to the other. I like the look of it more than anything; it’s different.
At the top of the bag there is an eskimo hood which has a toggle adjuster to pull it in tight. Around the neck, there’s a ‘3D Thermal collar’, which is marketing speak for an insulated neck. This is also adjustable using a toggle and will pull in around your neck, allowing less heat to escape. If you are claustrophobic, you might like to try this out before a live run.
The two toggles used here are secured to the bag with a short piece of material and they sit only a centimetre or so from the attachment point. This means the elastic moves through a fixed point, which is great when doing it up. However, when it comes to getting yourself out, the inability to move the toggle means you either have to squeeze it and expand the collar with the other hand. Or, you have to squeeze it and pull the elastic through the other side, before pushing the collar open. I would have preferred the toggles to move along the length of the elastic freely.
The two ends of the 3D collar have a velcro system so you can join them together, securing it around the full 360° of your neck. The only way to fasten it is to attach the ends before the main zip is fully closed. Otherwise, you’ll be fumbling around – probably in the dark – trying to marry up four bits of velcro. Maybe this is a system which sounded good in practice but is entirely unpractical in reality.
There’s also a little pocket along the zip at your shoulder. It’s good as a battery warming compartment and big enough to stick a head torch in, but you’ll never squeeze an iPhone 6+ into it.
I tested the Smoozip -7 out in almost freezing conditions and found it kept me nice and warm with its dual-fibre Microguard insulation, throughout the night. Inside the sleeping bag, I was wearing socks, trousers, an insulated jacket and a hat but no thermal base layers. I didn’t find myself needing additional warmth or having to do the hood up as the temperature outside dropped.
I also only used a 3/4 length, lightweight sleeping pad – the Klymit Inertia X-Lite – which was stowed inside the bag.
The mid-section and foot area is filled with additional insulation to keep the important areas warm. If you want to know their name for this, it’s Thermozone. Otherwise translated as ‘additional warmth in various places’.
In the morning, I found that the bag had breathed pretty nicely. The bottom of the bag felt quite cold against the ground where it had sat – remember, my sleeping pad was inside my bag – but there was little to no moisture present. Jack Wolfskin call the outer fabric ‘Softtouch 50D’, so as well as being soft and breathable, it should also be pretty robust against snags and tears – which was a relief when I released there were still some thorns underneath the tent!
The Smoozip -7 feels pretty roomy, with a length long enough for someone who is 6ft2in and a width that allows your body to rotate inside it without too much of an issue. You might feel squeezed by the tightening 3D collar but you certainly won’t from the overall size.
So what does all this cost you in terms of weight? Quite a lot, actually. It weighs in at 1940g (4.2lbs) which is substantial. It’s as much as the Exolight II tent I was carrying.
For comparison sake: A Marmot Trestles 15 sleeping bag retails at the same price, has a comfort rating which is much lower, at -4.6°C, and weighs 200g less. There’s the Mountain Equipment Starlight IV, which is good for -5°C, and also weighs 200g less. All three are synthetic.
In terms of pack size, it fares better against the competition, squeezing down to 45cm x 27cm. You’ll struggle to get it in the bottom pocket of their Highland Trail XT60 rucksack, especially if it’s full with other kit.
The stuff sack is two-stage, which means there are two layers of toggles to tighten it down. I would most definitely have preferred a compression-strap system here, which would have reduced the pack size slightly more. I can only imagine they went with the toggle/string system to save a bit of weight. The lack of compression straps also make it much more difficult to strap to the base of a rucksack securely.
I’ve ended up writing at length about a couple of features that didn’t perform quite as well as expected, but overall the Smoozip -7 is a sleeping bag I really like using. When the weight penalty and pack size don’t matter, you are left to enjoy the warmth and cosiness of the bag and its insulating collar. You might also find that you get less tangled up in this bag, in comparison to some others.
At £100, it’s not a big-budget bag and in the case of its weight, you certainly don’t get big-budget lightness. However, the feature set is there, if you’re prepared to use it, and the price is low enough to get you a high quality sleeping bag for most of your winter excursions.
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