- In stock
- Backordered, shipping soon
- Free Domestic Shipping On Orders Over $150 (Excluding Oversized and Bikes)
- Add To Cart For Final Price
One of the best parts of Smartwool® base layers is that they help reduce some of the uncomfortable distractions intense activity can produce. These bottoms feature our Intraknit™ technology—where insulation, articulation, and ventilation are seamlessly integrated to help with movement and comfort. The fabric helps combine the moisture management, temperature regulation, and odor resistance of Merino with TENCEL™ Lyocell fiber to help keep you cool. And with minimal seams to help reduce chafing, these bottoms will allow you to focus on taking your workout to the next level. So go out there and feel good doing it!
Intraknit™ 3D-Knit Technology
Intraknit™ technology seamlessly integrates insulation, articulation, and ventilation into the bottom itself — not added as separate panels or underarm gussets. The mapped knit construction shapes the bottom for the way the leg actually moves: ventilation runs through high-heat areas, insulation sits over the quads and seat where warmth is needed, and articulation zones allow the knee and hip to flex without binding.
Merino + TENCEL™ Lyocell Performance Blend
58% Merino Wool, 19% TENCEL™ Lyocell, 14% Polyester, 6% Nylon, 3% Elastane. The Merino handles the moisture management, temperature regulation, and natural odor resistance that defines the Intraknit™ collection. TENCEL™ Lyocell adds a cooling softness that pure Merino can’t deliver alone — the fabric breathes more on high-output days and feels cooler against the skin during warm-weather workouts.
Body-Mapped Ventilation & Insulation
The Intraknit™ ventilation zones are mapped across the upper thigh and behind the knee where heat builds fastest during exercise. Integrated insulation zones sit over the quads and seat where warmth is needed most. The ventilation runs through the knit itself — no mesh panels, no zippers, no added bulk.
Minimal Seams To Reduce Chafing
Minimal seams designed to help reduce chafing and allow you to work out distraction-free. The 3D-knit construction eliminates most of the traditional seam lines — the bottom is knit in one continuous form rather than assembled from panels. Fewer seams means fewer chafe points on long runs, long hikes, and high-output days.
Slim Fit For Body Contours
Our slim fit is intended to follow the contours of the body without excess bulk. Engineered in men’s proportions — contoured through the hip and thigh, articulated at the knee, with a waistband that sits where men’s base layers actually sit. Layers cleanly under hiking pants, ski pants, or running tights without bunching.
3% Elastane For Stretch Recovery
The 3% elastane content delivers the stretch recovery a fitted activewear bottom needs across the knee, hip, and thigh across hundreds of wear cycles and washes. The bottom holds shape across long training blocks without bagging at the knee or waist.
Multi-Activity Versatility
Built for the wide range of high-output activities where a heavier midweight base layer would overheat — trail running, gym training, HIIT, threshold cycling, shoulder-season hiking, and ski-touring warmups. The temperature-regulating blend handles the output swings without the clammy chill a synthetic would develop.
All-Season (Not Midweight)
All-Season weight positions this bottom as the right choice for high-output activity and shoulder-season layering — not deep-cold base layer duty. Lighter than the Classic Thermal midweight 250g/m² bottom; the right weight for runs, HIIT, threshold work, and cool-to-cold days when midweight would soak through.
Natural Odor Resistance
Merino’s antimicrobial properties keep the bottom fresh through long workouts, multi-day trips, and back-to-back training days without holding the funk that synthetic base layers pick up by day two.
Made In Vietnam
58% Merino Wool, 19% TENCEL™ Lyocell, 14% Polyester, 6% Nylon, 3% Elastane. Exclusive of Decoration. The polyester and nylon add structural durability; the elastane adds stretch recovery; the Merino and TENCEL do the work against the skin.
Technology
Intraknit™ 3D-Knit (Insulation + Articulation + Ventilation seamlessly integrated); Merino + TENCEL™ Lyocell Blend; Minimal Seams (Chafe-Reducing); Slim Fit; All-Season Weight.
General
Product
Men’s Intraknit™ All-Season Merino Base Layer Bottom
Fit
Slim fit (follows the contours of the body)
Silhouette
Long base layer bottom (full-length, slim)
Category
Base Layer Bottom (All-Season, 3D-knit Intraknit™)
End Use
High-Output Activity, Shoulder-Season Layering, Trail Running, HIIT, Ski/Snowboard
Technology
Intraknit™ 3D-knit (Insulation, Articulation, Ventilation zones); TENCEL™ Lyocell blend
Gender
Men’s
Available Sizes
S, M, L, XL, XXL
Sister SKU
Women’s Intraknit™ All-Season Merino Base Layer Bottom (SW003054) — women’s fit alternative in the same Intraknit™ family; Men’s Intraknit™ All-Season Merino Base Layer Crew (SW002868) — matched top half
Construction
Fabric Weight
All-Season (lightweight)
Fabric Composition
58% Merino Wool, 19% TENCEL™ Lyocell, 14% Polyester, 6% Nylon, 3% Elastane
Knit Construction
3D-knit Intraknit™ — body-mapped insulation, articulation, and ventilation
Seam Construction
Minimal seams (chafe-reducing)
Country of Origin
Made in Vietnam
Sustainability
Recycled Content
0% recycled (Merino/TENCEL/Poly/Nylon/Elastane blend — no recycled fiber blending in this SKU)
Responsibly Sourced Wool
ZQ-certified Merino wool
Tencel
TENCEL™ Lyocell fiber (FSC-certified wood pulp)
Washing
Machine wash cold on a gentle cycle. Wash separately — the Merino + TENCEL™ blend benefits from isolated washing to protect the fabric’s moisture-wicking and cooling properties. Cold water protects the elastane recovery and the TENCEL™ fiber structure. Use a mild, technical wash; avoid fabric softeners and bleach.
Drying
Tumble dry low. Heat helps the Merino + TENCEL™ blend re-loft and restores body-mapped ventilation. High heat can shrink the Merino fibers and damage the elastane recovery — keep the setting low and remove promptly.
Bleach & Iron
Do not bleach. Do not iron. Bleach breaks down Merino wool fibers and destroys the elastane; iron heat can scorch the Intraknit™ 3D-knit structure and flatten the body-mapped ventilation zones.
Dry Cleaning
Do not dry clean. The harsh solvents used in commercial dry cleaning strip the natural lanolin from the Merino and degrade the TENCEL™ Lyocell and elastane structure, leaving the bottom brittle and prone to losing stretch recovery.
Storage
Fold and store in a cool, dry place between sessions. Merino’s natural odor resistance means the bottom can be worn across multiple training days without daily washing — useful for trail runs, hut-to-hut tours, and multi-day training blocks where a daily wash isn’t practical.
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.
