RAB’s history dates back to the early 1980’s when famed British alpinist Rab Carrington started sewing high quality down jackets and sleeping bags in his home attic. Almost 40 years later, RAB remains one of the leading manufacturers of down clothing and their expertise is readily apparent in high-end, specialized pieces such as the Zero G and Infinity G jackets.
Designed with technical alpine climbing in mind, these jackets are pared down to just the essential features to minimize packed size and overall weight. Both share the same ultralight 7d Pertex Quantum GL outer which is a very fine, supple, yet incredibly tough fabric with an excellent DWR finish. It compresses like no other fabric I’ve experienced, and feels almost non-existent in hand. Though it looks and feels fragile I’ve been surprised by how durable and tear-resistant it is, and other than a tumble down a gravelled slope that put a couple small holes into the Zero G’s cuff, I’ve managed to keep the jackets remarkably tear-free.
(Zero G is the blue one, the Infinity G the red one.)
The Zero G uses the same 7d fabric for the inside lining, but it doesn’t have many additional features to list. There are two fairly large hand pockets with tiny zippers, a lightly elasticated hem, stretch-woven cuffs, and a helmet compatible hood. The stuff sack is similarly minimal, with the tiniest of drawcords and barely-there hang loops. Somewhat annoyingly, there’s nowhere on the jacket to attach the stuff sack and because there are only two hand pockets, I am loathe to keep the tiny 6-gram, same-coloured, bag in the Zero G’s pocket for fear of losing it (I’ve misplaced it dozens of times, including ‘losing’ it inside one of the pockets. It would be really useful if the stuff sack came in a contrasting colour, or at least had flashes of colour on it to make it easier to find.)
The Infinity G trades the ultralight 7d Pertex liner for a more pedestrian lightweight nylon fabric, which is still a very fine denier and remarkably packable. There are two large hand pockets, albeit with more substantial and easier-to-open zippers than those found on the Zero G. The Infinity G also adds a zippered inside left chest pocket, a stretchy drawcord at the hem, and a dual-slider main zipper. The hood is also a bit bigger and fits more easily over my helmets. The stuff sack is the same 7d fabric used for the outer, but with a burlier drawcord closure and a much more substantial (and too large, in this case) hang loop, though it still barely adds up to a whopping 8-grams on my scale. It is also in the same colour as the outer fabric but thanks to the large, contrasting-colour, hang loop is easier to find (plus I tend to store it in the chest pocket, so don’t misplace it as often).
Fit-wise, I had to go with a Men’s Large in both models, as opposed to my more typical Men’s Medium fit in RAB jackets. In Large, either jacket fits over a harness loaded with gear, and the hems are long enough to keep my butt covered and warm. The Mediums would also fit me but feel just a bit too tight for belay duty — I don’t know how much heavier the Large is vs the Medium, but I can’t imagine it’s significant. For reference, the Zero G weighs an almost incomprehensible 286-grams, while the Infinity G comes in at 422-grams (not including the 6- and 8- gram stuff sacks, respectively).
Warmth-wise, the Zero G is much warmer than it appears thanks to the 1000-fill-power goose down filling. The size large has 130-grams of the stuff, and it’s easily warm enough to use as a belay parka in -15c or so, but I tend to wear it almost everywhere because it’s so lightweight. It doesn’t ever really feel like you’re wearing a jacket, and the experience is hard to describe: there’s stuff around you, and you can see the material and feel the warmth radiating back at your body, but it just doesn’t ever feel like you’re wearing something — if that makes any sense.
The Infinity G uses 850-fill-power Nikwax-treated Hydrophobic goose down, 240-grams of it, and it feels quite a bit warmer than the Zero G — I’ve happily worn it at -25c and it was perfectly warm and wonderfully cozy over my usual cool-weather layers. The jacket is noticeably more substantial and feels more like a belay parka rather than the ‘invisible layer of warmth’ that I’d call the Zero G. And thanks to the hydrophobic down treatment, it is also more resistant to getting wet and performs significantly better in damp environments.
Other than the slight tears at the cuff of the Zero G, I haven’t managed to damage either jacket, but I have to admit I am much more careful around sharp screws and other pointy bits when wearing these jackets than I am with more heavy-duty apparel. I’ve also noticed that some of the down in the Zero G has shifted around, especially on top of the shoulders. It’s simple enough to manipulate the down back into position but it is annoying, and something that could be easily remedied with a couple more baffles on top of the shoulder to keep the fill in place. I haven’t noticed any down shift in the Infinity G.
The Zero G retails for $550 USD or $765 CAD, while the Infinity G is more approachable at $450 USD or $595 CAD. (Though the difference seems substantial, the conversion from US dollars to Canadian is about the same for either at around 1.35x.)
The Zero G stands on its own as a unique product as there is no comparable jacket out there that I know of. If you’re looking for the ultimate in ultralight warmth there is really no other choice, and despite a couple of small drawbacks like the lack of inside pockets and no double-sliding main zip, the Zero G is an outstanding piece.
The Infinity G, on the other hand, has about the same amount of down fill as other big belay parkas but at significantly less weight and at a lower, or similar, price point. It compares favourably to the others in warmth with the biggest difference being a slightly lower hem and a less robust, and therefore less wind-resistant, fabric and the associated slight loss of heat. But at 2/3 of the weight of the others, it’s a fair trade off if you’re looking for the best warmth-weight ratio.
I’d recommend the Zero G to anyone that wants the absolute lightest and warmest-for-weight jacket out there but for (careful) everyday, all-around, use the Infinity G wins out and is very highly recommended.
Huge thanks to RAB and RAB Canada for sending along the Zero G; I purchased the Infinity G out of sheer curiosity as I really wanted to compare these two to each other.