Arc'teryx Motus Crew LS

The Arc'teryx Motus Crew LS uses Phasic AR II 100% polyester to deliver exceptional moisture management for high-output activities. The trim athletic fit with articulated patterning moves with the body during running and hiking. Merrow-stitch construction reduces seam bulk while gusseted underarms enhance mobility. Priced at $85, this sits between lightweight base layers and heavier synthetic shirts. Available in 27 colorways: Black, Kingfisher, Pilot, Madder, Paradigm, Janus, Nocturne, Robotica, Red Beach, Aeroscene, Larix, Diablo Red, Mantis Green, Cinnabar, Adriatic Blue, Platinum, Blue Onyx, Borneo Blue, Galaxy, Iron Anvil, Ginko Leaf, Rigel, Cardinal, Exosphere, Neurostorm, Pangea, Kepler, Wood Violet. I wear this for cool-weather running because the Phasic AR II fabric wicks sweat faster than cotton or merino while providing UPF 25+ sun protection.

How Does the Arc'teryx Motus Crew LS Fit?

The trim fit sits closer than relaxed options like the Ether Crew while using lighter fabric than the Cormac Crew Neck LS. The articulated patterning follows body contours during arm swings and torso rotation. I wear a medium, and the Motus fits snugly over bare skin without restricting movement.

The crew neck sits close without choking. The sleeves extend to mid-forearm without bunching. The torso length stays tucked during running without riding up.

The trim fit layers effectively under shells or vests. I can wear this under a windbreaker during cold runs or under the Pelion Comp LS during hikes. The smooth exterior reduces friction when combining pieces.

Phasic AR II Fabric and Merrow-Stitch Seams

Phasic AR II uses specific knit construction that enhances moisture transfer compared to standard polyester base layers. The fabric pulls sweat away from skin and spreads it across the exterior surface for faster evaporation. This keeps skin drier during high-output activity.

The 100% polyester content dries faster than blended fabrics. After washing or getting caught in rain, the Motus dries completely in hours rather than overnight. This is critical during multi-day trips where I need gear dry by morning.

The Merrow-stitch seams sit flatter than traditional flatlock seams. This reduces chafing during long runs when my arms rub against my torso thousands of times. The smooth seams don't create hotspots even during marathon-distance efforts.

Best Between 40 and 60 Degrees for Running

This works well for 40°F to 60°F conditions during high-output activity. The trim fit traps a thin layer of warm air against skin while the fabric breathes enough to prevent overheating. For running in 40°F, I wear this alone.

Below 40°F, I add a fleece or windbreaker over the top. The trim fit slides easily under midlayers without bunching. Above 60°F, the fabric still wicks effectively but I usually switch to short-sleeve options.

The UPF 25+ protection shields against sun exposure during long runs or alpine hikes. The crew neck covers the back of the neck better than lower-cut base layers. The long sleeves eliminate the need for sunscreen.

Arc'teryx Motus Crew LS vs. Patagonia and Icebreaker

Patagonia's Capilene Cool Daily at $45 costs $40 less but uses heavier fabric that doesn't dry as quickly. The Patagonia fits looser and works better for casual wear.

Icebreaker's Merino 200 Oasis at $90 uses merino wool for natural odor resistance but costs $5 more and wicks moisture slower than synthetic during intense activity. The merino feels softer but takes longer to dry.

The Arc'teryx justifies the $85 price with Phasic AR II fabric, Merrow-stitch construction, and trim athletic fit optimized for high-output activity.

Built for Running, Not for Casual Wear

For running and high-output activities, the Motus Crew LS earns its price. The Phasic AR II fabric manages moisture better than standard polyester while the trim fit eliminates excess fabric that flaps during movement. The Merrow-stitch seams prevent chafing during long efforts. The quick-drying performance is critical for multi-day trips.

For casual everyday wear, look elsewhere. You're paying for athletic performance rather than comfort. If you need a shirt for around town, cotton or merino blends provide better casual comfort.

Arc'teryx prices this at $85 in 27 colorways. Material is 100% Phasic AR II polyester. Trim athletic fit with articulated patterning. Merrow-stitch seams. UPF 25+ sun protection. Best for high-output activities in 40-60°F.

Current availability at Arc'teryx.