Strafe Alpha Direct Insulator
Reviewer: 5’8”, 155 lbs
Size Tested: Medium
Blister’s Measured Weight: 272 grams
- Fabric: “Recon Air” 20-denier nylon ripstop w/ 2-way stretch
- Insulation: Polartec Alpha Direct — 90 g
- Air-permeable 2-way stretch face fabric
- Polartec Alpha Direct® liner-less insulation
- Forward seams at shoulders & extended side panels for pack compatibility
- Full length interior windguard
- Hem drawcord adjustment at side seams
- YKK Vislon® & Coil zippers
- 1 Chest (zippered) w/ interior electronics sleeve
- 2 Hand (zippered)
- 2 Interior (drop-in)
Test Locations: Crested Butte & Gunnison, CO
Days Tested: 12
At this point, nearly every outdoor apparel manufacturer is offering some sort of “active insulation” — pieces that are designed to keep you warm like your classic puffy jacket, but that breathe much better. They can be far more versatile than traditional puffies and fleeces, and are especially useful for high-output activities like skiing, climbing, running, etc.
One of the increasingly popular active insulations is Polartec Alpha Direct, which is essentially an extremely low-density knit fleece fabric that does not require a lining fabric (like you would need with down or Primaloft).
We’ve now reviewed a few Alpha Direct pieces, including the Outdoor Research Ascendant Hoody, Norrona Lofoten Alpha Raw Zip Hoodie, and the Rab Alpha Flash Jacket. The insulation breathes really well, but it seems a bit tricky to combine it with the right fit, fabric, and features to really make the most of the insulation.
The face-fabric-less Norrona and Rab pieces are super breathable, but lack almost any wind or weather resistance, which limits their versatility. The Ascendant, on the other hand, used a fairly dense and not extremely breathable face fabric, which limited the usefulness of the Alpha Direct insulation.
Strafe is another brand that is taking advantage of Alpha Direct, and I was very curious to see how well executed their iteration would prove to be. Could it hit the sweet spot of breathability, weather resistance, and warmth?
I tested the Alpha Direct Insulator in my standard size of Medium (I’m 5’8”, 155 lbs), and I’m really happy with the fit. It’s a bit slimmer than something like the Patagonia Nano Puff, yet not super slim like the Norrona Lofoten Alpha Raw Zip Hoodie.
As a result, the Alpha Direct Insulator is slim enough that it doesn’t bunch up when tossing a shell over it, and it’s not so skin-tight that it looks weird when just wearing it around town.
For how light it is (see below), the Alpha Direct Insulator has a lot of features, and they’re all very useful.
The Alpha Direct Insulator’s chest pocket is great for a wallet or phone, and the chest pocket’s interior mesh electronics sleeve keeps a phone more secure than it’d be if just sitting loosely in the pocket.
The two hand pockets sit fairly low, which mean that they get covered by a pack or climbing harness. This might turn off some people, but personally, I don’t care if my midlayer’s hand pockets get obstructed by a pack since I rarely use them while I’m wearing a pack. Plus, lower pockets are more comfortable when I’m not wearing a pack and want to warm up my hands.
Inside the Alpha Direct Insulator are two drop-in pockets that are a great place to store gloves, a hat, or anything else you want to keep warm.
The only complaint I have regarding the Alpha Direct Insulator’s features is the lack of an interior, insulated chest pocket. This is a very minor complaint and not many midlayers I’ve used offer both exterior and interior chest pockets (especially light ones like the Alpha Direct Insulator). But in a perfect world, I’d want a pocket where I could securely hold my phone, but that was next to my body so it’d stay warm. The Alpha Direct Insulator’s chest pocket has the insulation between the pocket and the inside of the jacket, so my phone doesn’t stay super warm when inside. Again, a very minor complaint.
At 272 grams for a Medium, the Alpha Direct Insulator is very light. It’s as light as the Norrona Lofoten Alpha Raw Zip Hoodie, yet the Alpha Direct Insulator has a face fabric that makes it more versatile.
When smashed down, the Alpha Direct Insulator is about the size of a 1-liter Nalgene.
For reference, here are some of our measured weights for a few notable pieces:
251 g Rab Alpha Flash Jacket, size Medium
272 g Arc’teryx Atom SL Hoody, size Large
272 g Strafe Alpha Direct Insulator
274 g Norrona Lofoten Alpha Raw Zip Hoodie, size Medium
299 g Patagonia Nano-Air Light Hoody, size Medium
364 g Patagonia R1 Hoody (stated weight)
365 g Outdoor Research Ascendant Hoody, size Medium
410 g Patagonia Nano-Air Hoody, size Large
415 g The North Face Summit L2 FuseForm Fleece ½ Zip Hoodie, size Medium
416 g Patagonia R1 TechFace Hoody, size Medium
427 g The North Face Ventrix Hoodie, size Medium
437 g Patagonia R2 TechFace Jacket, size Medium
The Alpha Direct Insulator uses two main fabrics: the 90 g/m2 Polartec Alpha Direct insulation, and a very thin, light, 2-way stretch ripstop shell fabric.
The Alpha Direct insulation is similar to high-loft fleeces like Polartec Thermal Pro, but is a bit more “airy” and lower density. I find it to be very cozy and comfortable on skin.
The Alpha Direct Insulator’s shell fabric is super thin, and it slides well under layers (something that non-shelled Alpha Direct pieces like the Rab Alpha Flash jacket do not do well). The Alpha Direct Insulator’s shell fabric also has just enough stretch so that I’ve never felt like I was restricted by the jacket while skinning or skiing.
Overall, I think these two fabrics work really well together, and I’ll dive more into that further down.
The Alpha Direct Insulator’s DWR-treated face fabric provides a touch of water resistance, and a bit of wind resistance. The fabric will bead up a very light rain, and I’ve found that I can stand out in fairly heavy snow for about 20 minutes before the face fabric starts to wet out.
In terms of wind resistance, the Alpha Direct Insulator offers what I think is a pretty great compromise. It blocks enough wind so that I don’t feel like I have to toss on a shell in ~20 mph gusts (and therefore compromise the breathability of the piece). But at the same time, it breathes quite well. This makes it much more versatile than the face-fabric-less Alpha Direct pieces like the Norrona Lofoten Alpha Raw Zip Hoodie and Rab Alpha Flash. Don’t expect the Alpha Direct Insulator to be able to fend off extended rain or wet snow, and the wind will cut through during fast gusts. But for a highly breathable midlayer, I think its weather resistance is quite good.
If you’re coming from a traditional down or synthetic (e.g., Primaloft) puffy jacket, I think you’ll be very impressed with the Alpha Direct Insulator’s breathability. It breathes far better than puffies with traditional, crinkly, sweat-inducing ripstop lining and face fabrics (e.g., Patagonia Down Sweater and Nano Puff).
Compared to the many other “active insulation” pieces out there, the Alpha Direct Insulator is still near the top when it comes to breathability. I’d say it breathes a bit better than the Patagonia Nano-Air and North Face Ventrix, and similarly to the Patagonia Nano-Air Light Hoody.
When put up against the extremely airy Norrona Lofoten Raw Zip Hoodie, the Alpha Direct Insulator is a bit less breathable, particularly when there’s any wind. However, I find that I can use the Alpha Direct Insulator in a wider range of conditions since it does block a bit of wind.
Compared to fleeces like the Patagonia R1 and R2, the Alpha Direct Insulator doesn’t breathe quite as well. But it’s a similar story here as with the Norrona piece — since the Alpha Direct Insulator blocks some wind and precip, I find that I can use it more often without a shell than I could with something like the standard R1.
Like most of the active insulation midlayers, the Alpha Direct Insulator falls somewhere between traditional puffies like the Patagonia Nano Puff and lighter fleeces like the Patagonia R1 when it comes to warmth. The Alpha Direct Insulator kept me plenty warm when paired with a shell and light baselayer while skiing at the resort in temperatures ranging from around 0°F to about 32°F.
While that temperature range might not look huge on paper, it is pretty significant when compared to less breathable puffies and lighter fleeces. I’ll typically only use a puffy like the Patagonia Nano Puff when it’s quite cold (less than 15°F), and I’ll usually only use a fleece like the R1 or R2 when it’s warmer than around 20°F. But since the Alpha Direct Insulator has kept me comfortable in the range of temperatures I typically ski in throughout an entire season, I’m very happy with its level of warmth.
The Alpha Direct Insulator uses a very light face fabric, so I wouldn’t want to brush it up against a bunch of trees, branches, ski edges, etc. But after 12 days of using it both under a shell and on its own, I don’t have any durability issues to report. I’ll update this section if I notice anything in the future.
Who’s It For?
Anyone who wants a versatile midlayer that will keep them warm in a wide range of winter temperatures, but that also breathes much better than most similarly warm puffy jackets. I find that the Alpha Direct Insulator works particularly well for resort skiing when paired with a shell, and I also like using it on its own while skiing in temperatures below ~20°F.
In addition to being versatile in terms of what temperatures it works in, the Alpha Direct Insulator is also versatile in that it just looks pretty stylish, which is often not the case when it comes to technical mid layers.
The Strafe Alpha Direct Insulator is a warm, breathable, and versatile midlayer that works well in a variety of temperatures and for a wide range of activities (and non-activities like lounging on your couch). If you want one midlayer to use for ski touring, resort skiing, and hitting the bars afterward, I highly recommend the Alpha Direct Insulator.