We know it’s unusual, but we do quite genuinely get really excited about sleeping bags. We’re not daft though: we know that not everyone does. No matter how much fancy detail goes into making them, at a glance they all look pretty similar, and most people just care that their bag keeps them warm and doesn’t weigh a ton. And even then, they only really notice it if it isn’t any good.
That’s perfectly understandable, of course. A decent sleeping bag (when it’s in your backpack) lets you get on with whatever you’re doing, or (when it’s not) encourages you to sleep: it tries its hardest to be ignored.
So, with that in mind, we’re going to shine a spotlight on our unassuming, simple-looking but nevertheless remarkably exciting Superlight 400!
It’s part of our Mountain Marathon Collection, and that means runners in autumn and winter multi-stage events (in the UK and Ireland) sleep in it to recover and recharge for the next day’s stage. So that means warmth, the ability to handle damp, and being small enough to carry when you’re running for miles. Potentially in horizontal sleet. Not that the sleet has much of a bearing on the bag itself, but if you’re having to put up with that, you’re liable to get increasingly bitter about hefting around gear that’s bulky and overweight.
Which is why the Superlight 400 is rated down to -8°C, shrugs off the condensation that drips off a cold winter tent, but only weighs about as much as a pint (without the glass).
So how do we get it to do that?
Well, the filling is 950 fill power goose down, which is so ridiculously springy that you need hardly any of it; the lining fabric is our “7X” 7 denier nylon, and the Ultrashell outer fabric – as well as being really rather light as well – has a permanent water resistant coating. And that’s all quite impressive, right enough, but the bit that really lights our candle is the way it’s put together.
Our bags generally use what’s called ‘box-wall’ construction. The outer isn’t sewn directly to the inner: a series of fabric strips are sewn in between them, creating square-section tubes to fill with down. This means the down can loft up without being pinched together by stitching. With us so far? Good.
In the Superlight, the top is still box-wall as normal, but the base is stitch-through: the lining is sewn straight to the outer. If you’re going be squashing the down in the base by lying on it anyway, then we don’t need to be quite so careful about letting it expand. And this means that there’s less fabric, which means there’s less weight.
It’s more involved to make because there’s a separate base and top, but still, it’s a deceptively simple concept, and, well, 570g for a -8°C bag: isn’t that cool?!
That really is how we feel about the Superlight 400…in fact, that’s how we always feel about sleeping bags. OK, they all kind of look of a piece with one another, but if we can make something seemingly ordinary do something remarkable, then yes, we don’t mind admitting we’re really quite excited about that.