[An honest, self-funded comparison review] Lightweight active insulation perfect for minimalist hikers, as revealed by actual wear comparisons

Wear

Thursday, January 4, 2024

Comparison , mid-layer , insulation , finetrack , Teton Bros. , OMM

Written by Haruki Murakami

I started using Discord

They say "active insulation is good"

Active Insulation is a hot topic on the streets as "cold weather clothing that lets you move."

Recently, many brands have released them, but honestly, it's hard to know which one to choose. I had a hard time. For example,

What padding should I choose? Octa? Polartec Alpha Direct? Primaloft?
What difference does the shell (outer material) make?
Do you need food? (Food jams are stressful too.)
What is the balance between weight and warmth?
What are some convenient models that can be used as both outerwear and midlayers?

And so on. To avoid overheating after purchasing and using it, or conversely, not wanting to end up cold because it wasn't as warm as you expected, it's important to choose something that's suited to your activity. However, this is extremely difficult, and ultimately you won't know until you try it. Choosing active insulation can be a difficult decision

In this article, I've tested three carefully selected lightweight active insulations for winter hiking in the field, comparing them and sharing my impressions of each model and my "favorite model." I hope this article will help you choose the best active insulation for you

table of contents

3 Minimalist, Lightweight Active Insulation Options
Test environment and field test results
- Test environment
- Field test results
Impressions of each model
Reference: Explanation of major items
summary

3 Minimalist, Lightweight Active Insulation Options

We selected three active insulation items for Fall/Winter 2023-2024 based on the following criteria:

Has a surface (not too breathable)
Not too warm for active wear
Weight less than 200g
No hood for layering purposes

Finally, taking into account appearance and other personal preferences, the following three points met my requirements

finetrack Polygon UL Jacket

OMM SuperSonic Smock

Teton Bros. Sub Jacket

The Sub Jacket/Teton Bros. weighs over 200g, but I chose it because I was very interested in the Stretch Octa padding

Test environment and field test results

Test environment

The padding and shells of these three jackets are different, but how do they actually differ? Also, what are the features advertised by the manufacturers actually like? We conducted a field test to check out the points of concern

[Period] November to December
[Mountain Range] Hakkyogatake (Nara), Konsho Alps (Shiga), Kyoto Loop Trail (Kyoto)
[Weather] Sunny, cloudy, rainy
[Activity] Fastpacking
Layering: Wear a base layer with active insulation

The test period, from November to December, is a time when the temperature changes greatly throughout the day. It's hot at the start of the climb, but once you reach the ridge and the cold wind blows, it suddenly gets colder, making it the perfect environment for testing. We proceed at a relatively fast speed using fastpacking style

Layering involves wearing active insulation over a base layer (sleeveless top). If you get too hot, remove the active insulation, and if you get cold, put on a shell (rain jacket)

If you're buying active insulation for the first time, you want it to be as versatile as possible. And if it's also lightweight and compact, that's even better. Which of these three insulations offers the most versatility? Here are the test results:

Field test results

type	Autumn/winter all-round type	Fine temperature adjustment type	Cold season active wear
item	OMM SuperSonic Smock	finetrack Polygon UL Jacket	Tetonn Bros. Sub Jacket
image
Here is ◎	Lightweight and compact Comfortable to the touch Moderate heat retention	Lightweight and compact Link Vent® ventilation No worries even in the rain	Sufficient heat retention A good balance of ventilation and warmth
Here is △	It's a hassle to put on and take off Retains water when wet by rain	Low heat retention Lining texture	weight The heat retention is a little too high
Outdoor Gearzine Review
Breathable	★★★☆☆	★★★☆☆	★★★★☆
Heat retention	★★★★☆	★★★☆☆	★★★★★
touch	★★★★★	★★★☆☆	★★★★☆
Ventilation	★★☆☆☆	★★★★★	★★★☆☆
Ease of movement	★★★★☆	★★★★☆	★★★★☆
quick drying	★★★★☆	★★★★★	―
weight	★★★★☆	★★★★☆	★★★☆☆
Specifications
padding	PRIMALOFT® NEXT	Fine Polygon	Stretch Octa
Outer fabric	PointZero	10 denier ripstop nylon	Prime Flex
Actual weight (g)	188 (Size M)	183 (Size M)	309 (Size M)

Impressions of each model

BEST: OMM SuperSonic Smock: Recommended for minimalist hikers for its just-right warmth, comfort, and functionality

This ultra-lightweight windproof insulation garment weighs just 188g (measured). The reason for its light weight is the combination of PRIMALOFT® NEXT, the extremely thin PointZero outer fabric, and the pullover design without a hood, making it perfect for minimalist hikers

I absolutely love how fluffy and warm it feels the moment you put it on. It feels completely natural against your skin, and it's by far the most comfortable of the three

The size and silhouette are just right for my body type and feel comfortable. It's also highly functional, with many convenient features, including easy packability, a built-in waist belt, the ability to double as a pillow (!), and the ability to stretch the sleeves to create a simple float. Walking around with the full zip open on a cold day can make your stomach cold, so I found a half-zip was sufficient

However, putting it on and taking it off can be a hassle, especially when wearing a cap. Also, if you put it on in a hurry, the lining can pop out. Putting your arms through the sleeves takes some skill (though once you get used to it, it's not a problem). The lack of a hood is also a matter of personal preference. Personally, I use the hood on my shell when it's cold, so I don't have a problem with the lack of a hood, and in fact, it's more comfortable because there's no hood congestion

My recommended layering combinations are a sleeveless top and a SuperSonic Smock, or a bare skin and a SuperSonic Smock. Even when worn against bare skin, PRIMALOFT® NEXT effectively absorbs and disperses sweat, making this a great layering combination for minimalists. I also plan to bring it with me to the Northern Alps in the summer as a thermal layer. In my case, it's 100g lighter

It's machine washable, so maintenance is easy. This active insulation is recommended for minimalists who want to eliminate waste and use one tool for two purposes

OMM Supersonic Smock [Official Online Store]

created by Rinker

168cm, 56kg, size M

PRIMALOFT® NEXT lining for a comfortable feel

The built-in waist belt is adjustable in length. Functional beauty with minimal adjuster

Worn with a waist belt

If you put it on in a hurry, the lining may come out. It takes some skill to put the sleeves on (although once you get used to it, it's not a problem)

The finetrack Polygon UL Jacket is easy to ventilate and layer, and is recommended for those who want precise temperature control!

This all-season thermal garment from finetrack combines moderate warmth with light weight (weighing just 183g!). It's compact and easily stowed in the right interior pocket. It's padded with our proprietary Fine Polygon®, sandwiched between a breathable outer layer and a sweat-management lining. It has the looser silhouette of the three pieces, allowing for versatile layering by pairing it with a long-sleeved T-shirt or hoodie. It's highly versatile

Of the three, this jacket has the lowest heat retention, but it's less likely to heat up. The Link Vent® allows for moisture release, and the zipper allows for fine adjustments. However, personally, I'm glad the Link Vent® is located on the side rather than the abdomen. It's highly water-repellent, retains heat even when wet, and dries quickly, so it's great for rainy days

One thing that concerns me is the lining, which gets sticky when you sweat and feels chilly when the temperature drops

A recommended layering combination is the "Long-sleeved T-shirt Hoodie + Polygon UL Jacket." The Link Vent® and full zipper keep you cool while you walk, and when it gets cold, you can wear the hood of the base layer or layer another thin mid-layer for comfortable winter hiking in low mountains. With a long-sleeved T-shirt, you won't have to worry about the softness of the lining against your skin

I thought the design and colors of the finetrack were a bit off (sorry!), but I like the color range and silhouette of the Polygon UL Jacket and find it easy to use. Personally, I wear it below 10°C if it's a sleeveless top, and below 5°C if it's a long-sleeved T-shirt. It's machine washable, so maintenance is easy. This is active insulation recommended for those who want precise temperature control throughout a wide range of seasons, from early autumn to the depths of winter

Finetrack Polygon UL Jacket Men's (M)

created by Rinker

finetrack

¥24,139 (as of 2026/02/07 21:23:57, according to Amazon - details)

168cm, 56kg, size M, base layer is a long-sleeved T-shirt hoodie

Polygon UL jacket lining

Stretch material used in part of the sleeves

Recommended for winter activities and hikers who are sensitive to the cold! Teton Bros. Sub Jacket

It uses the newly developed Strech Octa, which has an excellent balance of heat retention and moisture management, and is highly functional with detailed cutouts, a full zip, and large-capacity pockets. The Teton Bros. color lineup was so popular that it was hard to choose

Of the three, this is the heaviest (actually weighing 309g!) and thickest, providing excellent warmth. I felt that its intended temperature range and activities were on a different level than the other two. The sense of security when you put it on outdoors in the cold is unmatched, and the moment you put it on, you feel a comfortable feel and warmth against your skin

The stretch of the Strech Octa means that it doesn't feel too tight, even though it has a snug silhouette. The snug silhouette also allows for easy movement even when wearing a shell, and it's stylish (unlike the original Octa)

One thing that bothers me is that it's not packable, so it takes up a lot of space in my backpack. Also, for someone like me who enjoys hiking in snowy mountains below the tree line, I felt that the insulation was a bit excessive

This active insulation is recommended for those who enjoy hiking in the mountains in sub-zero temperatures, those who are sensitive to the cold, and those who like to walk slowly

Teton Bros. Sub Jacket (Unisex) (L, Gunmetal)

created by Rinker

Teton Bros

168cm, 56kg, size M

Stretch Octa lining for the Sub Jacket

Reference: Explanation of major items

Breathable

To evaluate the results, we tested the product by blowing air from a fan onto it (at a temperature of 16°C). The order in which we felt the airflow was the best was as follows:

The first place goes to the Sub Jacket, which is made of thick fabric but still allows the wind to pass through
Second place goes to SuperSonic Smock
Lastly, by a narrow margin, the Polygon UL Jacket

By the way, these three items didn't feel cold even after being exposed to a fan for several tens of seconds, but the product that directly uses Octa (Air Mesh 1/2 Zip / Mountain Hardwear) let in so much wind that I couldn't stand it for even a second. This is to be expected since there is no shell, but the degree of airflow is completely different

Heat retention

These are the items that clearly showed a difference. For reference, I've also written down the temperature range I tend to wear clothes in (this is just a guideline!)

The first place goes to the Sub Jacket, which has a thick outer layer and is heavy (wear it if the temperature is below 5°C)
Second place goes to PRIMALOFT® NEXT's SuperSonic Smock, which traps air (below 8°C)
Finally, the Polygon UL Jacket (below 10°C)

quick drying

The weights were compared after spinning in a washing machine and drying outside for 30 minutes (cloudy, 20°C, gentle breeze). Since the Sub Jacket cannot be washed in a washing machine, the comparison was made with the Polygon UL Jacket and the SuperSonic Smock. The test results were..

The first place went to the Polygon UL Jacket. After 30 minutes, it was 31g lighter and almost dry, which surprised me!
Second place went to the SuperSonic Smock, which was 25g lighter after 30 minutes and had retained some moisture

By the way, after dehydrating, I put on the Polygon UL Jacket and the SuperSonic Smock, and both items felt to be sufficiently warm

summary

After field testing three minimalist, lightweight active insulations, the one I wanted most this season was OMM's SuperSonic Smock

The deciding factor (although it may depend on the time of year when you test it) was the balance between warmth and wind resistance. Also, the overall balance of comfort, functionality, and the number of features made me want to wear it again and bring it with me next time

However, while the OMM was the best for me this time, when I compared the other two carefully, each had its own unique features and appeal. For example, the Finetrack is highly breathable and can be worn in a wide range of seasons, while the Teton Bros. is more resistant to low temperatures. The best model will vary depending on the mountain range, season, activity, etc. I hope this comparison review will be helpful when making your decision

Haruki Murakami

I've been mountaineering for 5 years and UL for 2 years. I'm a hiker who is still experimenting. I love long hikes. I also love traveling, and I travel both domestically and internationally. I'll be sharing my thoughts from a beginner's perspective in an easy-to-understand way that will make readers think, "I'm going to the mountains again next week!"