The Coefficient LT Crew is the perfect baselayer for high output activities, from alpine approaches, backcountry tours or mountain runs.
We trust what we make because we use what we make. All Black Diamond soft goods are warrantied against defects in materials and construction for the practical lifetime of the product.
From clean climbing, to conservation, Black Diamond is committed to protecting the people and places we love.
At Black Diamond, we're committed to going deep, whether that's into the mountains, the design process, or the community we love. Our fall/winter collection of equipment and apparel is built for the experience of casting off, and diving into the deep end of adventure.
Overall rating: 4.9166665 / 5 from 12 reviews.
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"Like it."
"great fit, very good quality. Becoming my favorite crew."
"My go too for cooler weather fitness and climbing."
"Was purchased to be used a long sleeve. It’s closer to a base layer like a long john than a snug fitting shirt. It’s very thin but very warm under another shirt. It’s not the same thickness as the coefficient hoody. Still happy with the product."
"Amazing Base for skiing and Ice climbing. Wicks moisture and keeps me warm and dry all day long."
"Awesome base layer but these are REALLY fitted and run small. I used the sizing chart to size for myself knowing the exact measurement of my chest. There’s no way I could wear this as anything but a base layer because it’s so fitted. A bit disappointing but I ski and climb a lot so I’ll use it for a base layer and likely still wear it out."
"This shirt keeps you warm and breathes so well . I use it bike riding with an Alpine Start Jacket in the morning temps of 35-45F and it’s perfect. Super comfy , stretchy and light. I’m 6’1” 160lbs and use the medium."
"I have the 1/4 zip version of this layer and it's been a great addition for outside adventures. It's THIN, but uses polartec grid fleece technology to help hold in heat on cooler days, but it stays very breathable for higher aerobic adventures like biking, ski touring, XC skiing, and all around exploring. I would recommend sizing up AT LEAST one size depending on how you choose to wear it as it's described as a slim cut and it definitely lives up to this description. I'm 5'11-ish and around 170 lbs and I'm a true medium in Black Diamond jackets and vests. For this piece I ordered a large because of the slim fit designation, and really all I can wear under it is a compression base layer (think under armor) or a close fitting top. Definitely think about how you are going to use the top when sizing because its a slim fitting cut. Overall I'm getting some great uses out of this piece and continue to find more uses for it. Not sure if I'd wear it mountain biking especially since my local (Fruita Colorado) trails tend to be on the rocky side and I think it would have a hard time surviving a rocky spill. Overall big fan so far."
"Love BD for their amazing gear and weightlessness of gear, while being better than anything else I own. I love this coefficient as it is an excellent base layer for activity while keeping you very warm and actively cools while still keeping you warm at high output. My go to for alpine sports, mountaineering and trail running in winter"
"great layer warm and light. Fits well."
| Size | Chest | Hip | Arm Length |
|---|---|---|---|
| XS | 34 - 35.5 in 86.5 - 90 cm | 33.5 - 35 in 85 - 89 cm | 33.5 in 85 cm |
| S | 36 - 38 in 91 - 96.5 cm | 35.5 - 37.5 in 90 - 95.5 cm | 33.5 in 85 cm |
| M | 38.5 - 41 in 97.5 - 104 cm | 38 - 40.5 in 96.5 - 103 cm | 34 in 86.5 cm |
| L | 41.5 - 44.5 in 105 - 113 cm | 41 - 44 in 104 - 112 cm | 34 in 86.5 cm |
| XL | 45 - 48.5 in 114 - 123 cm | 44.5 - 48 in 113 - 122 cm | 34.5 in 87.5 cm |
Designed to fit slim to the body for an athletic, low-profile fit without restricting mobility and accommodating base layers or light midlayers.
A classic universal fit with comfortable ease. May feature slight body shaping, but predominantly straighter fit that will accommodate midlayers more comfortably.
Generous through the body for a casual loose-to-oversized fit without shaping. Designed for comfort, it accommodates heavier mid-layers.
Measure around the chest/bust just under the arms and across the shoulder blades.
Measure from the center back of the neck, across the shoulder, and down the arm to the wrist.
Measure around the widest point of the hips.
Measure around the narrowest part of the waist.
