Base Layer Bottoms

Reviewed by David Link

Versatile lightweight merino blend layer, perfect for winter backcountry use, chilly nights in camp, and just lounging around at home on cold days.

I’ve been a huge fan of Ibex clothing for many years. The Ibex Indie hoody I bought probably twenty years ago, is still one of my favorites. I was sad when they announced that they were closing a number of years ago and have been pleased to see that they have returned. I was eager to give these bottoms a try. I received the Woolies Tech Bottoms in late spring when our Northern California weather was generally too warm to use them much initially, but with colder and wetter weather descending on us this winter, I’ve been wearing them a lot.  Campground fashion statement rearview Fit and Comfort: The fit of the Woolies Tech Bottoms is as would be expected.

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Reviewed by Mike Mineart

The Patagonia Capilene Air Bottoms are Patagonia’s newest base layer design which utilizes a unique seamless knit construction that is composed of 51 percent merino wool and 49 percent Capilene recycled polyester. This results in a very stretchy insulation layer that is both light and warm. The knit construction provides a nice thickness that works extremely well inside of waders for long days fishing in cold streams. Overall this is a great base layer, especially for colder conditions.

Overview The Patagonia Capilene Air Bottoms are Patagonia’s newest base layer design that follows Patagonia’s long tradition of developing new fabrics with improved performance while also trying to find ways to minimize the impact on the environment. The Capilene Air Bottom fabric is a unique a 3-D seamless knit construction that utilize fibers made from 51 percent responsibly sourced merino wool and 49% Capilene recycled polyester.  The resulting bottoms are light, warm and very comfortable to wear.

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Reviewed by Andrew F.

The Outdoor Research Enigma Bottom is a base layer whose forte is wicking moisture and keeping you dry when you’re active; though the fabric has some wool content, it’s mostly synthetic (12% merino, 88% polyester). The fabric is relatively thin and very stretchy and slightly prone to pilling in high-friction areas. It’s an outstanding option for high-output cool and cold weather activities (four-season if you live in a cooler place), except you’ll want to wear them under a shell or fleece when it’s really cold.

BASIC INFORMATION Outdoor Research's Enigma base layers are a combination of wool and polyester—12% merino and 88% Drirelease polyester. Check out my recent reviews of the Enigma Half Zip top and Boxer Briefs. The synthetic part is Outdoor Research's DriRelease E.C.O., "Environmentally Correct Origins,” which is made from 100 percent post-consumer recycled PET, the material used to make plastic bottles and containers, and blended with natural fibers like wool. The bottoms have a one-inch wide elastic waistband, a fly, and a couple of seams mid-leg that run roughly above and below the knee.  FIT AND FEEL The Enigma Bottoms are true to size—you can rely on Outdoor Research's size chart.

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Reviewed by LoneStranger

A full-length base layer bottom that has real value on trail in all four seasons. Smartwool's Classic All-Season Merino Base Layer Bottom uses a 150g wool/nylon blend fabric that is heavy enough to add warmth when layered but light enough to use as a hiking tight in warm weather. Comfort and durability for use all year.

  Taft Lodge on the Long Trail (Vermont) Long a fan of Smartwool layers in winter, I spent this summer testing some of their gear that works well in warm weather. Along with the Merino Boxer Brief, which I wore almost every mile of the season, I also spent some time wearing Smartwool's Classic All-Season Merino Base Layer Bottom. Light in the pack and extremely versatile on the body I found these bottoms to be worth carrying on trips long and short. There is also a women's version of this.

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Reviewed by BigRed

Black Diamond's Solution 150 Merino Base 3/4 is a lightweight, polyester-reinforced merino wool base layer. Cool enough to wear under light shell clothing for high intensity activity at around-freezing temperatures without overheating, but easily layered over for use in colder conditions or at lower intensity. Stretch fabric gives a comfortable fit even on a slim frame and dries a little faster than 100 percent merino. 3/4 length works with high plastic cuff ski boots.

(Preliminary review based on the first month of use) Black Diamond’s Solution 150 Base shirts and long underwear are lightweight, polyester-reinforced merino wool base layers. They are light enough to wear under light shell clothing for high intensity activity at around-freezing temperatures without overheating, but easily layered over for use in colder conditions or at lower intensity. BD has supplied me with both a crew neck top and ¾ length bottoms for testing. Much of what I have to say about the one will apply to the other and so may be duplicated in both reviews.  The Solution 150 lineup also includes a full length bottom, and all three variants are also available in women's versions.

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Reviewed by OutdoorKelly

The Kari Traa Rose Pant is a 100 percent merino base layer that is comfortable, warm, and durable. It's thin enough to layer without restricting movement, and incorporates a range of colors and sizes to appeal to a variety of adventurous ladies! Just be prepared to size up as this base layer runs SMALL!

Testing Conditions: I tested the Kari Traa Rose Pant from December 2018 to December 2019 as a member of the Trailspace Review Corps. Testing conditions ranged from -25 to 20 degrees Fahrenheit in the following activities: hiking, fat biking, snowshoeing, backcountry skiing, alpine (resort) skiing, and nordic skiing.                                                                       Rose Pant, side view Fit & Comfort: For those who aren't familiar with Kari Traa, the Norwegian brand was developed by its namesake, a female Olympian freestyle skier. The Rose Pant is a base layer made of 100 percent merino wool.

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Featured review by Andrew F.

This is a fairly warm synthetic base layer, loose enough to serve as a mid-layer. I recommend wearing alone for cooler weather and beneath a shell or insulated pants in really cold weather. The newer version has two hand pockets rather than a back pocket and is sized even more loosely than past versions—including looser cuffs at the bottom. New ones also have a drawstring, a plus.

The R1 bottom is kind of like a versatile pair of outdoor sweatpants. They are thick enough to wear alone in fairly cool weather if you are active, and they are very warm if you wear them under a shell. On cooler summer nights, I'll often put them on as the temperature drops in camp.     FIT: The fit on these used to be pretty average. They have enough room and plenty of stretchiness to wear over a tight, lightweight base layer or running tights if needed. The current version is sufficiently loose that they wouldn't be a great deep cold base layer, but they now layer better over a base layer bottom.

Read more: Patagonia R1 Pants reviews (2)

Reviewed by Tun

Excellent base layer bottoms.

I was looking for a comfortable pair of base layer bottoms to keep me warm under my work dress pants. These things were perfect. I am about 5'11" 180 lbs with a 33/34 inch waist and I think the medium is a perfect fit. These bottoms are form fitting but not so constricting where it feels too tight or decreases my mobility. The material is very soft to the touch and stretchy. I have read stories about other base layer materials getting ripped by toe nails when people have tried to put them on, but this material has so far been very durable and doesn't seem prone to getting ripped by a toe nail snag.

Read more: Patagonia Capilene 3 Midweight Bottoms review (1)

Reviewed by KiwiKlimber

The Outdoor Research Alpine Onset Bottoms are soft on the skin and easy to maneuver in. They're best when on the move in cool/chilly temps like hiking or bike riding, and they are flexible enough for highly active pursuits.

Conditions and Temperatures:I tested the Alpine Onset baselayer bottoms, along with their crew top counterpart, the Outdoor Research Alpine Onset Crew top. These items are part of Outdoor Research's Alpine Onset collection, which includes an array of men's and women's layers. I’ve worn the OR Alpine Onset Bottoms for five months through the fields and forests of central Pennsylvania while hiking, camping, hunting, mountain biking, and for general everyday purposes. Temps have ranged from -18°F to 60°F (-28°C to 15.5°C), but based on my experiences, these baselayer bottoms are best suited for at or above freezing temps (32°F/0°C or above).

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Reviewed by Jake W

The Fjallraven Bergtagen Long Johns is a base layer pant that utilizes wool in three different weaves to maximize heat retention in key areas (butt, groin) and breathability in others (thighs, calves). It’s a total home run of execution and since I received this base layer for testing I have worn nothing else. It’s exceptionally well tailored, durable, doesn’t stink on multi-day trips, and you’ll have no fear around a fire. The only possible negatives are more inherent to wool, than this product—it takes longer to dry.

PREAMBLE Fjallraven is right up there with Arc'teryx in the confusing naming scheme of their products. The Woolmesh Long Johns is part of their Bergtagen line (Bergtagen is a Swedish word used to describe the feeling of being captivated and humbled by the mountains, awesome name), which includes the base layer (two top options and two bottom options, both men's and women's), mid-layer insulation (two different jackets for both men and women as well as a elephant style sleeping bag), outer shell (pants and jacket, both men's and women's) and a work layer (pants and jacket, both men's and women's).

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