Arc'teryx Rho LT Crew vs Smartwool Merino 150 Base Layer Top

Weight and specs compared for 2026 — and which one to choose.

Arc'teryx Rho LT Crew is the lighter option — 8 g lighter than the Smartwool Merino 150 Base Layer Top (5% less weight). If grams matter to you, that is the one to beat.

Spec	Arc'teryx Rho LT Crew	Smartwool Merino 150 Base Layer Top
Weight	155 g · 0.155 kg · 0.34 lb	163 g · 0.163 kg · 0.36 lb
Brand	Arc'teryx	Smartwool
Category	Clothing - Base Layer	Clothing - Base Layer

Arc'teryx Rho LT Crew

155 g

Lightweight Phasic base layer for cool and active conditions.

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Smartwool Merino 150 Base Layer Top

163 g

Lightweight merino wool base layer with excellent moisture management.

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Arc'teryx Rho LT Crew vs Smartwool Merino 150 Base Layer Top: which should you buy?

If saving weight is your priority, the Arc'teryx Rho LT Crew wins — at 155 g it is 8 g (5%) lighter than the Smartwool Merino 150 Base Layer Top (163 g). That said, the heavier option may justify the extra grams with more capacity, durability or comfort, so weigh the trade-off against how you'll use it.

See where both rank against everything else in this category on the lightest clothing - base layer page, or browse the full gear weight database.

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