Alpha thoughts (Rab Strata Hoody)

[David Chenault]

I was skeptical from the beginning about Polartec Alpha. The very idea of making a shelled insulation garment more breathable seemed questionable at best, as it seemed rather likely that light fleece plus a windshell would be a better solution in every respect. Fleece and a shell is probably a better option for most backpackers most of the time, but Alpha has merit and contrary to what I first thought, the Strata hoody has a place in my closet.

The Strata is vintage Rab, and has the same fit and feature set as the standard setting Xenon. Two zippered handwarmer pockets, zippered left chest pocket (which is huge and inverts as a stuffsack, drawcord hem, sculpted lycra-bond hood. A welcome change is a #5 main zip, as opposed to the #3 used on the Xenon (which blew out after two years on mine). An unwelcome change is the goofy cuffs, which have elastic on the inside half only. It's effective, but causes the inside sleeve near the wrist to puff out and get in the way. Fit is excellent; roomy but not baggy, very long sleeves, body long enough to stay sealed but short enough to not stick out under a raincoat. The Microlight shell is different from the normal versions of that Pertex fabric; it has a matte finish and is a bit softer and quieter than the stuff found in (for example) the Montane Litespeed. DWR is what you'd expect from a leading brand.

The sell on Alpha is that it breaths much better than traditional synthetic insulations like Primaloft and Apex. This is facilitated on the inside of the jacket by making significant portions of the liner out of mesh, and by the more air-permeable version of Microlight used for the shell. This works: the Strata moves moisture a lot faster than something like the Xenon. It's also not nearly as warm, something especially noteable given the increased weight (~16 ounces for the Strata, around 4 more than the same sized Xenon).

If you throw the Strata on for pure warmth, you'll be disappointed, especially under windy conditions. A bunch of testing here over the years has revealed that the more air impermeable fabrics (Pertex Quantum et al) add significant warmth to jackets and sleeping bags, and comparing the Strata to the Xenon or a similar traditional synthetic jacket proves this.

But warmth in the backcountry isn't so simple. A classic winter layering problem is sweating on the uphill (even when properly layering down and venting), then getting chilled on the flats and downhills which follow. Putting on a light synthetic coat like the Xenon sorta solves this problem, except that fabrics like Pertex Quantum are almost as good at keeping moisture in as they are at keeping wind out. Use the Xenon in this manner for a few laps backcountry skiing, or a few transitions on a hilly route snowshoing or cross country skiing, and you'll likely experience a steady accumulation of dampness in your base layers, and in the synthetic jacket. This usually works out ok on a day trip, when a warm car awaits or you can carry extra clothes, but can present a serious problem on multiday trips.

A piece like the Strata goes a long way towards solving this problem. It provides enough warm and wind blocking to keep core temp steady, and vents much better than anything in its class. Why is it better than putting a thicker fleece under your windshell? Simplicity. Stripping down to relayer is slow and, on a windscoured ridge, unpleasant.

I foresee the Strata being a part of a two puffy system for me this winter; with the Alpha piece being the moving puffy and secondary insulation, with a traditional synthetic jacket going over the Strata in camp. It won't be the lightest system, but it might be the most efficient over many days.

The Strata is also a nice mid/outer layer combo for slower activities in cold weather, or (I assume) higher output stuff in real cold. I wore the Strata over a capilene 4 shirt the other weekend mountain hunting on a day which barely got above 0 F. Having a two layer system which vented well enough when hiking up steep hills in the snow, and kept me warm enough while standing around glassing, let me focus on other things, stay comfy all day, and helped bag a nice deer that afternoon.

Discuss.

[Stephen M]

Dave,

I have one, and I also see it as part of a two layer
puffy system.

For me it sits well in my line up between a puffy
and a mid layer.

Did I not see yours for sale?

[Dave Marcus]

I picked up a Mammut Guye jacket at REI over the weekend and wore it on my ride to work this morning. It breaths better than my (2014) Houdini and kept me perfectly balanced once I started pedaling. In similar conditions, wearing the Houdini only, I've arrived at work sweaty. Not with the Guye. It's thin enough to wear as a mid-layer – it may replace my Stoic Merino Comp hoody – and is great on its own for chilly, aerobic activities.

Mammut has a slim cut with longer arms. I'd say it's slightly more slender than an Arcteryx "trim fit" piece.

I still want to pick up a Strata or a Nano-Air hoody as well, but the Guye will definitely find a niche in my wardrobe.

Now if only the Swiss would stop putting the zipper slider on the wrong side…

[Evan Davies]

I have one.
My usual system is(was) base>fleece>softshell(powershield/windstopper) with a hardshell in the pack for really bad weather and a down jacket for camp/stops.
I would normally not wear the softshell and hardshell together. In my mind I don't like wearing two membranes (not sure exactly how bad it would be if i did).

My Strata system is base>strata hardshell and down in pack and much happier layering the hardshell over the strata. If it's really cold I can add a fleece.

With a hardshell (which I almost always carry) I really don't need a membrane softshell and the Strata more or less replaces the fleece layer.

If I'm going out for a day hike in changeable conditions I'll often go straight for the Strata as I find it covers a lot of bases.

[Ethan A.]

I'm looking to go with a two insulation jacket system. This is how I'm thinking of using the Nano Air Hoody. Not cold enough to experiment yet (yes sometimes I really miss NE cold blasts).

-Base layer: Either Patagonia Cap 4 Hoody, or light merino T with Patagonia R1 Hoody

-Midlayer: Nano Air Hoody worn snug not loose, replacing a 200 wt fleece jacket

-Outer layer when needed: Light soft shell or waterproof jacket or wind layer (pre-2012 Houdini) depending on conditions. Even a light wind jacket like the Houdini thrown over a breathable Alpha piece should make it much warmer. Need to tinker here to see what works best.

-Belay layer: Puffy insulation jacket to wear at rest stops or in camp sized to wear over the Nano Air

Question: For your outer insulation jacket over the Nano Air, down or synthetic? Down will be warmer for the weight, but will it be a problem if you're pushing moisture into the outer down jacket over a multi-day winter trip?

A Polartec Power Dry grid fleece or 200 weight fleece + wind jacket or light soft shell has always worked very well for me. Alpha pieces seem like they offer more comfort by moving moisture better than the fleece/windshirt or softshell combo and by minimizing layer changes.

[David Chenault]

"Question: For your outer insulation jacket over the Nano Air, down or synthetic? Down will be warmer for the weight, but will it be a problem if you're pushing moisture into the outer down jacket over a multi-day winter trip?"

A good question, and one I intend to investigate. The Strata plus Primaloft jacket combo will probably get the nod most often just because my down coat is too warm most of the time.

Stephen, I decided to give it another try.

[Sean Passanisi]

Note that the Strata uses a heavier weight insulation (80g/m²) than the Nano Air (60g/m²). One would expect better performance while inactive (warmer) and perhaps worse while active (too warm).

I'm hoping someone can quantify the warmth difference between an Alpha piece (with and without a shell) and traditional Primaloft. My only puffy is an UL down hoody. I'm wondering if the downsides of heavier weight and less compressibility can be justified by increased flexibility and better performance in wet weather. I'm thinking I could use a nano air as my primary insulation, supplement with a nano air vest if it's colder, and use a parka-class down jacket if it's really cold.

[Serge Giachetti]

Thanks for your thoughts, Dave.

I had a similar experience to your hunting trip (stop and go) using the nano air for much of a drizzly fall weekend in Indian Peaks, except I taking pictures. In this shutterbug scenario, I'm used to messing around with layers quite a bit between windshirts, puffies and rainshells. The breathability of the piece made it good for on the move, but it also trapped enough heat while I was searching out frames and appreciating a new place.

Breathable insulation is good, not because its the best at any one thing, but, because its good at a lot of things, you can just 'leave it on' (as the marketing goes) through a variety of conditions and activities.

I find this piece surprisingly warm given its high air permeability. The breathability of the entire piece is (subjectively) similar to that of of my pertex equilebrium windshell. The impressive warmth serves to offset what might feel a little too breathable on windy ridges. Its definitely not as warm as my xenon was, but add a shell, and it feels similar to my arc nuclei, which isn't bad. The great stretch allows for a close fit for moving in, which is half the reason to have a piece like this IMO. Another reason is that in a lot of situations this could simplify your clothing system. And, like Dave said, its a better option than traditional shelled synthetic for moving moisture out of your layers. For backcountry skiing, I imagine I'll start with a mec t2 (like cap 4) hoody, and then mix and match the nano air, an equilebrium wind shirt, and a light down belay jacket (a 100 + gram primaloft would be even better. Since the warmth of this jacket layered under a more windproof puffy rivals other synthetics, you get another breathable layer for moving in, without losing warmth fully layered. Its also a pretty darn light at 13.6 oz.

I had about $150 patagonia credit just sitting around for a couple of years, so when a %20 discount came around, I thought it worth taking a risk on an expensive/unproven item. But after using it seamlessly for backpacking, climbing and skiing already, I can definitely see this becoming one of my most used pieces. What will be really great though is if they could make close fitting nano air pant with high ankle zips to fit over ski boots. It would be the perfect additive layer over a pair of tights or light softshells. Likewise, a vest, or even a warm belay style nano would be welcome. The only thing that could make it better would be if the stretchy fabric on the inside was better wicking. Regardless, it seems to quickly absorb moisture into the insulation, and away from your closer layers. Oh, and patagonia's hem cinches are perpetually awkward.

[Stephen M]

I am glad you kept it Dave.

Oh, does anyone find the hood a small bit boxey?

[David Chenault]

Update; basically my thoughts are unchanged. Some of the stuff below repeats what I've already said here, but I thought some might find it interesting. I have really enjoyed the Strata as a backcountry skiing layer.

Polartec Alpha was developed for the military, as an insulation which would form the core of a garment that would, as an insulator, better straddle the divide between static and dynamic warmth. Alpha does this by being more air-permeable than synthetic fill insulations such as Primaloft and Climashield, and at the same time more svelt (and thus better suited to shelled jackets) than fleece. Polartec says, "By placing patented low density fibers between air permeable woven layers we created a more efficient fabric for regulating warmth and transferring moisture."

Warmth in the outdoors is often understood as an overly simple concept. Static warmth for a dry, stationary body requires only decent fueling and hydration and enough layers. Dynamic warmth, where said body is in various states of motion through varied environments, is governed by the same rules, but they are interrupted by the need to protect from external, while venting and moving internal, moisture. Achieving a balance between external protection and internal insulation is, most of the time, the key to sustainable activities in the outdoors.

Passable solutions to the various permutations of the moisture problem have no doubt existed for millennia. Pretty good ones have existed in the modern clothing paradigm for decades. What continues to be an occasional complication is finding a way to balance protection and insulation across a range of settings with minimal items of clothing, and with minimal alterations within the items carried. It is in this area where Alpha might make sense for some outdoor uses.

Alpha is not as warm for a given weight as the down and synthetic fill insulations to which we've become accustomed. The Rab Strata Hoodie weighs about a pound in size medium, 3-4 ounces heavier than the almost identically featured Rab Xenon X. The Xenon not only has a lighter weight (60 g/meter v. 80 for the Strata) of warmer Primaloft One insulation, it has a lightly lighter and far less air-permeable shell and liner fabric. One of the marketing saws for Alpha jackets, and the Toray-made clone used by Patagonia and Kuiu, is that the structure of the insulation does not demand the densely woven nylons which have become standard for Primaloft. This may or may not be the case, but I tend to believe that for an Alpha jacket to function coherently as a unit the liner and shell must do what they can to keep pace with the insulation. If Alpha can breath better and wick faster than the liner, moisture will stay stuck inside, against the wearer. If the liner and insulation can move moisture faster than the shell, or at least much faster, water vapor will become trapped inside, and in cold enough weather, freeze solid.

The Strata Hoodie does not do any of these things, and the liner (zoned mesh and light nylon ripstop) and shell (nylon plain weave with a textured inner face) seem ideally matched. The Strata moves moisture several times faster than the Xenon X.

This comes at a cost, and that cost is static warmth. The outdoor garment industry has taken a enhanced interest in breathability in recent years, one result being the many more, more air permeable garments available. Polartec Neoshell in the hardshell realm, woven windshirts like the Alpine Start, and Polartec Alpha are all examples. Breathability happens via moisture transport, and moisture within clothing systems happens via evaporation, which necessitates evaporative cooling. One of the reasons the Xenon and Xenon X jackets have made their reputation as the warmest garments of their class is the very air impermeable Pertex Quantum liner and shell. Summit a windy ridge after a sweaty climb and throw on the Xenon X and you'll get immediate and considerable shelter from the wind.

The disadvantage is that the Quantum shells will also hold that sweat inside, and it will take time and often an external heat source of consequence to dry the jacket out completely. It is in these circumstances that I've become enamored with the Strata. It often provides enough extra warmth and wind resistance to serve as a resting or skiing-down jacket, while still moving moisture. The difference between how dry the Strata will keep me over the course of a day skinning and skiing laps compared with the Xenon is considerable. Similar things can be said when hiking slowly in moderate cold, or hard in serious cold. Worn over appropriate base and wind layers, these combinations are very effective, and impressively free from the need for constant adjustment.

The disadvantage of the Strata is in turn the lack of warmth, which is not due entirely to the increased air permeability. Patagonia hyped their Nano Air (which we can safely view as darn close in function to Alpha jackets, just with stretch), as the equal to Primaloft coats provided a very wind resistant shell (i.e. hardshell) was put over it when needed. My anecdotal experience is that this is not the case. 80 g/meter Alpha is significantly less warm than 60 g/meter Primaloft One, even when the two are compared strictly on terms of static warmth.

As a matter of backcountry policy, the Strata is often a very useful critter, but in most circumstances requires an additional insulating layer. What will best serve as a companion here, providing enough warmth without too much additional weight, bulk and complication, I have not yet decided. Fleece works well enough, but does not directly address the need for additional wind resistance, and insofar as both are bulky and suited to use on the go this combination is duplicative. Another, more traditional synthetic fill shell makes sense, but results in a heavy and bulky system. My hope, for spring hunting, hiking, and skiing, is to use a down vest in and outside the Strata. I will report back.

[Ryan Bressler]

I've had a westcomb tango (alpha + pertex equilibrium) for most of two winters now and love it.

My experiences largely match Dave's though the Tango does have some stretch. It is quite fitted in the wrists/arms and hood making it perfect for use as a mid layer but hard to get the sleeves over anything thicker then a baselayer+tight fitting shell.

On the whole I'm a big fan of polartechs new fabrics. Some of of the most comfortable and dry winter days ski touring involved a cap 4 hoody, westcomb tango and a powershield pro softshell or windshit…I can just manage wear the tango over the shell or the shell over the tango which really simplifies adding and removing layers.

I'll usually also bring a windproof down or primaloft layer for rest stops/emergencies as none of the above layers block much wind and I tend to get cold quite easily when i'm not moving. I'll often finding myself throwing on the tango at a summit and not needing to take it off until i'm back at a car.

That being said, I found I basically stopped using the Tango in the spring when it isn't cold enough to need more active insulation then the cap 4 hoody offers.

[Sean Passanisi]

Thanks for the feedback, David.

How would you compare the relative utility of an Alpha/ Nano Air vest to your hoody? How about a jacket (non-hooded) version?

[Rick M]

del

[Steve K]

In my experience with both Alpha and FullRange, I am disinclined to wear them for hiking as I heat up and sweat very quickly, and having a backpack on I am unable to vent moisture through what must be 30-40% of the surface area that makes up the fabric, once you account for the back and shoulders being covered. Even then, the coldest temperatures I've faced (-14ºF) have been perfectly tolerable for hiking with an R1 and Squamish, and a light puffy for the first few minutes until I begin to feel core warmth.

If one such hiking jacket were designed with just DriClime style fleece in the back and Alpha in the rest of the garment and a similarly lightweight hood I could see it as removing many of my layers from necessity in the winter, perhaps being the one garment to rule them all.

Now on the other hand, the Alpha and FullRange stuff have been absolutely brilliant for rock and ice climbing, where you may exert yourself hard for periods of time and get sweaty but mostly just need to be comfortably warm as you ascend the wall and belay your partner. I've also found the breathable insulation to be a real boon for cross country skiing and cycling, although the Strata feels as if it cuts the wind much more effectively than the Nano Air. Dare I say, I think the Strata might be a better jacket for heat regulation save for the absolutely amazing feel and comfort of the Nano Air.

If I am going to have one jacket only, I would rather have the Strata over the Nano Air, but if I am going to wear a belay parka, the Nano Air is far more comfortable when layered over.

[David Chenault]

Sean, I think a vest might be more useful than a jacket here, especially for a backpacker.

Rumor has it that Rab will have an Alpha coat with stretch fabrics this coming fall/winter.

[Woubeir (from Europe)]

"Rumor has it that Rab will have an Alpha coat with stretch fabrics this coming fall/winter."

Their Paradox pull-on. :-)

[Mike M]

any more insight on this garment? thinking about pulling the trigger on one- a synthetic garment that is mildly warm and could be used on the move in cold conditions

[Stephen M]

I am very impressed with my one Mike. For me serves function as a fleece and a light synethic.

[Eric K]

Mountain Equipment just came out with the Kinesis which has Polartech Alpha for insulation, a moisture wicking jacket lining and a lightweight water resistant shell. It looks interesting. I am passing on it as I picked up a Montane Axion Neoshell which has the Neoshell membrane with the Alpha insulation, so should breathe fairly well in the colder temps I envision wearing it. Eric

[Woubeir (from Europe)]

Not to complicate things, but maybe you should look also at Primaloft Silver Insulation Active as it is by far the warmest of the tree.

[Mike M]

well backcountry had it on sale and they just announced a additional 20% off sale items, sooooo….. I should have one in a couple of days to give a whirl :)

[Brian Lindahl]

I guess I don't really get this piece still. I've found that I pick a baselayer thickness that suits the temperatures, and then add/remove a stretch-woven softshell to add/remove warmth. I've never had to adjust my baselayers with a midlayer, even down to days starting out at -10F or so, that end up with highs around 20-25F and sunny? I wonder if it's the high level of output from ski touring compared to a much lower level of activity from mellow hiking? I'm curious how many of you that are praising the alpha layers have tried a stretch-woven softshell with an appropriate-thickness baselayer? (I don't change the baselayer thickness throughout the day – just add the softshell in the morning, remove it once I warm up, and put it back on whenever I get cool, whether it be at the end of the day, or if the winds pick up)

[Mike M]

I'm looking at this garment as a light insulating layer, that can also be used on the move in the right conditions. I see this piece fitting in shoulder season/winter. In winter a warmer insulating layer will be needed in addition to the alpha piece. Much of shoulder season I see this being the main insulating layer (augmented with a shell). Last years Bob Marshall Open I brought a light down jacket, the weather was definitely nicer than normal (drier) and it worked out fine. I hope we have the same weather, but I'm going to be better prepared for more normal weather- cold rain, wet snow. There is little to no lounging about camp, so the insulating doesn't need to be overly warm. To me it bears at least some similarities to a soft shell.

[Richard Fischel]

as i've mentioned in other posts it's become my go-to jacket in place of a wind-stopper zipper front fleece for around town and office wear and while it hasn't replaced, it's become a solid substitute for my polartec power stretch hoodie/wind shirt combination in a number of situations. it lives in a similar space as a non-membrane soft shell jacket, but is warmer and more versatile. i'd wear this over a soft shell except if i wanted better abrasion resistance. it's just an incredibly comfortable jacket to wear over a broad temperature spectrum.

[Serge Giachetti]

@brian, thats my typical system for bc skiing as well, except with an equilebrium windshirt or vapour rise. So far, I've mostly used my nano air on the downs for ski touring. I have noticed that it helps me dry off my base layers better and also vent out extra heat I may generate if conditions are tough. It really came into its own on a multi day traverse last winter though. We had long stretches of mostly down, with intermittant skating and skinless shuffling where i was glad to have the nano. And then there was a warm day where we were skinning hard uphill for miles and built up quite a sweat. We got above treeline and had to do some scrambling to avoid avy slopes, by which point it was howling wind and full on winter conditions again. I used the nano here. By the time we got over the pass we were exhausted and took a long break. My baselayer was pretty much dry at this point and i hunkered down in a second puffy very comfortably. There's a # of things that would have worked there but I was quite happy with how the nano did. The ideal use though is cold weather climbing though. That paradox looks good, but it would be more versatile with a full zip. I like my nano a lot, but from what i gather the insulation will degrade more than the thermal pro based alpha.

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