Smartwool Men's Classic Thermal Merino Base Layer Bottom
Smartwool Men's Classic Thermal Merino Base Layer Bottom
Smartwool Men's Classic Thermal Merino Base Layer Bottom
Smartwool Men's Classic Thermal Merino Base Layer Bottom
Smartwool Men's Classic Thermal Merino Base Layer Bottom
Smartwool Men's Classic Thermal Merino Base Layer Bottom
Smartwool Men's Classic Thermal Merino Base Layer Bottom
Smartwool Men's Classic Thermal Merino Base Layer Bottom
Smartwool Men's Classic Thermal Merino Base Layer Bottom
Smartwool Men's Classic Thermal Merino Base Layer Bottom
Smartwool Men's Classic Thermal Merino Base Layer Bottom
Smartwool Men's Classic Thermal Merino Base Layer Bottom
Smartwool Men's Classic Thermal Merino Base Layer Bottom
Smartwool Men's Classic Thermal Merino Base Layer Bottom
Smartwool Men's Classic Thermal Merino Base Layer Bottom
Smartwool Men's Classic Thermal Merino Base Layer Bottom
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Men's Classic Thermal Merino Base Layer Bottom

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Men's Classic Thermal Merino Base Layer Bottom

We've updated our Men's Classic Thermal Merino Base Layer Bottom to bring you a better fitting, more functional tight. The technical benefits of 100% Merino wool will help you keep your game at a high level for longer. And our warmest-weight wool fabric will help keep you warm and comfortable as you ski, run, and hike the day away.

Award-Winning Midweight Warmth
Midweight 250g/m² ZQ-certified Merino hits the sweet spot between insulation and breathability for cold-weather starts and stops — warm enough for the chairlift, breathable enough for skinning up.
100% Merino Wool Fabric
Single-jersey knit of 100% Merino wool delivers moisture management, body-temperature regulation, and natural odor resistance. Interlock construction keeps the next-to-skin layer soft against the leg.
Slim Fit With Contoured Cut
Cut to follow the contours of the body without compression. The slim profile layers clean under an insulation pant or shell bib without bunching at the knee or ankle.
Flatlock Seam Construction
Seams are designed to sit flat against the skin and minimize chafing during high-rep movement — skinning strides, skate skiing, repetitive hikes where standard seams rub raw.
Merino-Lined Elastic Waistband
The waistband is lined with Merino where it sits against the lower back — the spot that gets sweaty under a pack belt or hip belt. Manages moisture in a place most base layers ignore.
Fully Functional Fly
Real fly construction, not a sewn-shut panel. Single-layer Merino knit holds shape without a separate gusset or stitching that creates bulk or cold spots.
30" Inseam (Size Medium)
Cut to land at the top of the boot without bunching under a sock or riding up under a shell pant cuff. Sizing runs true — order your normal pant size.
Made in Vietnam: 100% Merino Wool
Single-material construction keeps the fiber story honest — what goes against your leg is what comes off the sheep.

General

Product
Men's Classic Thermal Merino Base Layer Bottom
Fit
Slim fit (True to Size, based on customer reviews)
Category
Base Layer Bottom
Fabric Weight
250g/m² (midweight)
Gender
Men's
Available Sizes
S, M, L, XL, XXL
Recommended Uses
Skiing, Snowboarding, Hiking, Running, Climbing

Construction

Fabric
100% Merino Wool (interlock knit)
Seam Construction
Flatlock seams for chafe resistance
Waistband
Merino-lined elastic
Inseam (Size M)
30" (76 cm)
Country of Origin
Made in Vietnam
Washing
Machine wash warm on a gentle cycle with like colors. Turn the bottoms inside out before washing to protect the outer knit and help release body soil from the inner fibers. Avoid fabric softener, which coats Merino fibers and reduces moisture-wicking performance.
Bleach & Iron
Do not bleach. Cool iron as needed; do not iron decorations. Bleach breaks down Merino wool fibers; high heat can scorch the knit and damage the elastic recovery of the waistband.
Drying
Tumble dry low. Heat helps the Merino fibers re-loft and restores the fabric's natural performance. Remove promptly to minimize wrinkling.
Dry Cleaning
Do not dry clean. The harsh solvents used in commercial dry cleaning strip the natural lanolin from Merino wool and degrade the elastic — both of which are core to the bottom's fit and performance.
Storage
Store folded in a dry space. Merino's natural odor resistance means you can wear the bottoms multiple days between washes on multi-day trips — the perfect performance feature for hut-to-hut tours and backcountry ski days.

Shipping Policy

Components:

All component items (wheels, drivetrains, suspension, brakes, etc.) ship within 4-7 business days of purchase.

Bicycles:

Complete bikes typically ship within 2–3 weeks due to build, tuning, and inspection times. You will receive tracking information as soon as your order is ready to ship.

Riding Gear & Apparel:

Riding gear and apparel orders (helmets, jerseys, gloves, etc.) ship within 3-10 business days.

Returns & Exchanges:

If you received the wrong size or wish to exchange an item, it must be returned in original condition—unused, uninstalled, and with all packaging intact.

For full details, please see our Refund Policy before initiating a return.

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Merino Layer System — SW016361
LAYER 01
Skin
Base layer sits directly against the skin.
YOU ARE HERE
Mid Base
Midweight Merino bottom — Layer 02 of the system.
LAYER 03
Insulation
Fleece or synthetic pant for deep cold.
LAYER 04
Hardshell
Waterproof shell pant or bib for wet + wind.

Built For

Cold-Weather Hiking
Cool — Cold
Multi-hour days on trail when the wind picks up and the temperature drops. The 250g/m² midweight holds warm air close to the leg without overheating on the climbs, and the slim cut moves with the stride under a shell.
Backcountry Skiing
Cold
Skin track up, descent down. Merino manages the sweat from the climb so it doesn't freeze against the skin on the way down. Flatlock seams sit flat under a shell bib where hip-belt pressure would otherwise rub raw.
Shoulder-Season Running
Cool
First 35°F mornings before tights become overkill. Midweight is enough to take the chill off the quads on the warmup without becoming a sauna by mile three. Merino handles the sweat — no post-run chill.
Daily Winter Wear
Cold
The woodpile, the morning commute, the shop. Under jeans or work pants when the cold moves indoors. Odor resistance means multi-day wear between washes without the funk that hits synthetics by day two.
Build The Stack

Pair It With The Top

A matching top completes the system — same fabric, same weight, same fit. Pair with the Men's Classic Thermal Merino Base Layer Crew or 1/4 Zip for a head-to-toe Merino foundation that goes under any insulation or shell.

  • Classic Thermal Crew cold-weather starts
  • Classic Thermal 1/4 Zip vent on the climb
  • Smartloft Vest core insulation on top
  • Hardshell Jacket full weather protection
Layer Over It

Add A Shell On Top

The bottom is the foundation; the shell is what you put over it when conditions turn. Merino handles moisture and warmth on the inside so the shell only needs to handle wind and wet.

  • Waterproof shell pant wet + wind
  • Insulated ski pant lift days + deep cold
  • Softshell pant cool + dry days
  • Shell bib deep snow + hip belt

Prepared with intention.

Every product is carefully inspected and handled by our team before it ships. From fit and function to final details, we make sure each piece is ready for the outdoors ahead—so you can focus on the experience, not the gear.

Passion drives us

At SpokeX Bike Co., bikes aren't just our business — they’re our way of life. As a rider-owned and operated shop, every decision we make comes from firsthand experience on the trail, at the race, and on the open road. We know what it’s like to chase a new line, push through the pain cave, and celebrate the ride — because we live it every day.

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