Wind Shirts + Alpha Direct: The Next Layering Revolution for Thru-Hiking?

The best and lightest backpacking gear seems to change by the week. Every time I go online, there’s a new tent or backpack making waves in the hiking community. Certain categories are brimming with innovation, while others stagnate for years or decades at a time. As such, I don’t find myself being tempted very often by the latest and greatest in hiking clothes. When I first saw an alpha direct hoody however, my interest was piqued.

I saw a few Senchi hoodies on the CDT in 2021, and was impressed by how light, comfortable, and breathable they appeared. While I didn’t jump on the new tech immediately, it did come to mind every time I was stifled under my 10oz grid fleece or was chilled to the bone by a cold breeze. By the time the 2023 hiking season came around, I was ready to explore new ways to lighten my packed clothes and improve their performance.

READ NEXT — Senchi Merlin Hoodie Ultralight Fleece Review

What’s Wrong with the Grid Fleece?

The grid fleece has dominated the hiking mid layer game for decades, offering significant warmth while allowing perspiration to escape between the cells of the shirt. I’ve used some sort of grid fleece since I started seriously backpacking in 2017, finding it usually suited my needs for active insulation. It’s a pretty effective layer, with a few flaws.

First, the gaps between cells are essentially areas of no wind resistance. This means a strong breeze can cut through to your base layer easily, causing a strong chill even during high-output activities. Some fleeces use a slightly more opaque face to prevent this, but it significantly reduces their breathability. More wind-resistant fleeces are typically heavier too, in some cases by as much as 60% compared to their grid-based versions.

Second, thin grid fleeces offer too little warmth and weather resistance, while midweight fleeces become heavy very quickly. In my size range, a grid fleece typically weighs in around 10-14 oz depending on the pockets, hardware, and inclusion of a hood. At the same time, a puffy jacket in that same weight range is significantly warmer (but less breathable). For something that works in a narrow range of conditions, that’s a lot of dead weight in the pack throughout the day.

READ NEXT — The Best Fleece Midlayers for Thru-Hiking

The Runner’s Choice: Wind shirts

During a high-output activity, like running or uphill hiking, a grid fleece is often too warm, while going with a baselayer only leaves most people feeling too exposed to the elements. A strong breeze cools the body down quickly through both evaporative and conductive heat loss. This is especially true when you are already sweating your way up a big climb.

Runners have long adopted the wind shirt as the go-to for neutralizing the effects of wind. They are significantly more breathable than rain jackets and rarely leave the clammy feeling that typically comes from opaque layers. By taking inconsistent and chilling wind out of the equation, keeping a constant temperature becomes a lot easier. Most wind shirts are also absurdly light — even versions with pockets, zippers, and full-length hoods still weigh under three ounces.

The New Kid on the Block: Alpha Direct

Okay, so now we’re sold on the humble wind shirt, but for chilly days one by itself isn’t going to cut it. Unfortunately, with wind mercifully out of the equation, that trusty 10-14 oz grid fleece is too warm as an active layer. Wind shirt + grid fleece = lots of sweat. Yet replacing the grid fleece with a lighter weight, non-grid fleece is going to kill the breathability of the whole layering system. And putting on another T-shirt-like layer might not sweat you out, but it isn’t going to do much for warmth either.

Enter Alpha Direct, a newer fleece technology that is super light and super warm. This fabric has been on the market since 2017, but didn’t gain popularity in the hiking world until 2021 when Senchi Designs started to get hoodies to the masses. In the few years since, several other companies have started offering Alpha Direct clothing to meet the demand of its rabid fans.

A Strong, Independent Insulation

Alpha Direct isn’t your grandpa’s fleece. With fabric weights from 60-190gsm (grams per square meter), this material is far lighter than typical fleeces. And unlike the lightweight synthetic insulation of years past (such as Apex and the similar Polartec Alpha insulation), Alpha Direct is structured enough to be used as a standalone garment.

This removes the need for puffy-like construction with an additional face fabric that provides no real benefit other than keeping the insulation in place and protected. By using such a lightweight material and completely eliminating whole layers of fabric, a fully finished hoody made with Alpha Direct can weigh as little as three ounces. A layer that with similar warmth as a typical grid fleece will still only weigh 6-9 ounces.

Garments made of this material also absorb amazingly little water. Made of polyester, the actual fiber has an inherently low water capacity compared to nylon or cotton. Combine that with a spacious weave, and very little water gets trapped between fibers as it does with other garments of different weaves and materials. In fact, Alpha Direct absorbs so little moisture that my hoody comes out of the washer spin cycle practically dry. The low absorbance and open weave also leave little space for perspiration, which vents very easily.

Alpha Direct: What’s the catch?

Unfortunately, dropping 50+ percent of your insulation weight does come with a few downsides:

1. No wind resistance: Even the breeze created by walking at normal speeds is enough to flush out the accumulated warmth. This means the fabric has little effect when it is used as an outside layer and is best worn under something else.
2. Delicate: Using a very loose, spiderweb-like weave, the fabric snags easily. Quick contact with velcro can be devastating, and the laundering directions usually call for a special bag to prevent these layers from getting torn apart.
3. Plastic pollution: While all synthetic fibers are thought to shed microplastics, Alpha Direct has been observed to be worse than most. The loose weave is prone to heavy shedding during wash and activewear, especially during the first few months of use. The “macro” plastic pollution of lost fibers can stick around wherever they land and contribute to more widespread pollution. Many companies producing these garments now include a microplastic wash bag, but most hikers won’t carry this on a thru-hike, and it doesn’t prevent the issue of backcountry shedding.
4. Short lifespan: Heavy shedding and delicacy mean Alpha Direct garments have a shorter lifespan than comparative layers. This is both costly and wasteful. While a decade of regular use is not out of the question for conventional grid fleece hoodies, I would be very surprised if my 90gsm Senchi lasted more than two or three years.

READ NEXT — A Light History of Alpha Direct, That See-Through Ultralight Fleece!

The Holy Grail: Wind Shirt + Alpha Direct

Wind shirts and Alpha Direct are a match made in heaven. The shell perfectly compensates for the insulation’s deficient wind performance, letting each part perform its core function in perfect unison. Given how both pieces are so lightweight, you can combine them to form a functional layering system for 30-40% less weight on your back versus alternative systems.

Having your mid layer separated into two garments also makes it more modular. The stand-alone wind shirt can be worn solo on breezy but warm summit attempts. The Alpha layer can be worn under a rain jacket during a cold downpour.

My Setup: No more Melly

At 7.6oz combined, I find my 90gsm Senchi half zip hoody and Montbell Tachyon combo to be about equally warm as my 11.5oz Melanzana Micro Grid Hoodie V2, without the lackluster performance in strong wind. Furthermore, if I wanted to boost my warmth-to-weight ratio even more, I could squeeze out another ounce or two by substituting similar Alpha Direct and wind shirt layers without pockets and chest zips.

Combining two highly breathable and wicking layers, this combo dumps perspiration. I very rarely accumulate sweat when wearing these, and when I do, a few minutes of rest leaves me fully dry. With A DWR-treated wind layer, you can even get through a light misting without having to put on a clammy rain jacket.

I picked up my Senchi and Tachyon combo before the Wind River High Route this year, replacing the Melanzana Micro Grid in my packing list. The extra versatility of using the wind shirt by itself came in handy on multiple occasions, such as summiting Europe Peak at 40% grades and 12,000ft, but also 40mph winds. Previously, my choice would have been between feeling the wind cut through the grid fleece or accumulating buckets of sweat under my rain jacket.

The weight savings versus my Melly were also significant by UL standards — dropping 4 ounces from my already sub-10 pound baseweight.

The Way of the Future

Now that Alpha Direct garments have had a few years on the market and availability has improved, this dynamic duo is rapidly gaining popularity across the Triple Crown. Within a few years, the pair could dominate the mid layer category for all thru-hikers. If you’re looking to lighten your clothing category and want a more flexible layering system, there are plenty of wind shirts and Alpha Direct fleeces at various price points.

Where to find the Goods (aka Favorite wind shirts and Alpha Direct layers)

Alpha Direct Layers

Senchi 60gsm
MSRP: $85
Weight: 3-5oz

Senchi 90gsm
MSRP: $95
Weight: 4.1-6.9oz

FarPointe Alpha Cruiser
MSRP: $85
Weight: ~4oz

Squak Mountain Co Squak Alpha UL
MSRP: $70
Weight: 4-5 ounces

Wind Shirts

Montbell Tachyon
MSRP: $140
Weight: 2.6 ounces

Enlightened Equipment Copperfield
MSRP: $120
Weight: 2.1 ounces

Dooy Wind Shirt
MSRP: $20
Weight: ~2 ounces

Featured image: An Alex “GPS” Brown photo. Graphic design by Zack Goldman.