Mountain Equipment Impellor Jacket
Mountain Equipment's lightest waterproof shell, the Impellor is well suited to any weight conscious activity from hill running and ultralight walking to minimalist mountaineering, says Dave Saunders
First and foremost, the Marmot Nano shell jacket is light.
And not just rather light, or quite light, but ridiculously light.
At 227 grams, it only weighs a bit more than a couple of quick-draws. If light weight is your priority, it is worth considering for that reason alone. To get down to such a miniscule weight you just get less jacket – but not in a bad way. Firstly Marmot have used Gore-tex Paclite, they have used micro-taping and lightweight water resistant zips, but that isn't enough. The jacket is also cut carefully to produce a slim, athletic shape with no unnecessary, baggy or flappy material. This makes fit important: the medium is a good size for me but I'm limited with what fits underneath – a base layer and a micro-fleece. With it being increasingly common to add a synthetic belay layers over our shells, this isn't a big issue but you may need to size up from your normal if you want to wear thicker layers underneath.
To get down to such a miniscule weight you just get less jacket – but not in a bad way
You can describe the jacket pretty quickly because it is so simple: Paclite Gore-tex, a full length waterproof zip, two chest pockets that also serve as extra venting, a peaked and wired hood, elasticated cuffs and very light drawcords at the hem and around the face. That's pretty much it. Paclite I find breathable enough for hiking in, but within about 15 minutes of cycling in it at an average speed on a cool day, I find that I begin building up sweat inside. This will go away again once I lower my exercise rate, but for my metabolism Paclite isn't breathable enough for cycling or jogging without getting damp. There are some holes stamped through the layer of Paclite that forms the back material of the pockets; this means that when the pockets are opened they can serve as pit-zips and allow extra ventilation but I'm not convinced this system is really enough to make much difference. Even cycling at some speed with the pockets open, it was hard to detect the extra ventilation from this arrangement. My feeling is the jacket is too slim a fit to allow the pockets to open enough to allow much air flow through. The cuffs are elasticated and can be pushed up your arms to allow more ventilation, although my preference is for velcro cuffs particularly if you are likely to be wearing the jacket with gloves on.
The hood is interesting and worthy of separate note. A number of UKC users have noted on the forums that many of the other ultra-light waterproofs have rather poor un-stiffened hoods that offer little protection from driving rain. The Nano goes the other way with hood that is both wired and uses a cleverly shaped piece of harder plastic in the brim to make a rigid peak whilst adding very little to the weight. This clever design produces a rather “British style” of hood, not the best for periphery vision but excellent protection in heavy weather. My concern about the hood is the sizing: you can wear it over a helmet but for me, the jacket is then pulled tight into my armpits. It is as if the hood is the right size in two dimensions, from ear to ear, and from forehead to the back of your head, but isn't high enough – meaning the rest of the jacket is pulled upwards. I've tried this with both a Petzl Meteor and CAMP Armour helmet and it happens with both. It will be amplified if you wear a cradle-style helmet such as an Ecrin Rock or Edelrid Ultralight, both of which tend to sit higher on the head than more modern hybrid and foam helmets. Trying to avoid climbing in heavy rain I very rarely wear a hood over my helmet, so this is one of those niggles I could live with. But just a little extra volume in the hood would for me turn the Nano from being a good ultralight alpine climbing shell to an excellent one, and if you are thinking of buying it specifically for that purpose, it would be worth trying one on first with your normal helmet to see if this issue bothers you, or consider buying a size up.
The Nano is, in some ways, quite a specialist bit of kit. Most importantly it is very, very light and compact – making it the perfect waterproof not to wear. But when you do have to wear it, it works well and, with its wired hood, provides more protection than some other super-light shells. The materials and components being so light, will not last forever, although having said this I still regularly use my Arcteryx Paclite shell that I've had for nearly six years and it still does its job. The Nano clearly won't be as tough as some other shells, but then those kind of shells tend to weigh twice or even three times as much. If your priority is weight, then the Nano is well worth a look; just check how the hood fits if you think you will be wearing it regularly over your helmet.
Weight: 227 grams
Marmot's UltraLight offering in GORE-TEX® Paclite® is an evolved solution for long treks in spotty weather. 100% seam taped with an elastic draw cord hem and water resistant zippers throughout, the Nano is guaranteed to keep you dry without weighing you down. Pack pockets feature laser-drilled pocket backing that enhances breathability.