Quick answer
For pure cooling on hot days, the Pro Air Short Sleeve Base Layer II's open mesh fabric wins, but the Women's ARC Merino Long Sleeve Base Layer offers temperature regulation that works across a wider range of conditions.
How fabric choice affects temperature
Mesh and merino handle heat differently. Mesh actively pulls sweat away and lets air flow through, which is ideal when you want maximum evaporation. Merino, on the other hand, naturally adjusts to your effort level, keeping you warm when you start and cool as you push harder.
When mesh excels and where it falls short
The Pro Air Short Sleeve Base Layer II uses an all-over open mesh that quickly moves sweat and promotes airflow. This works best on sustained efforts where you want to stay dry and focused. The trade-off is that mesh offers little insulation, so it's less useful on cool mornings or for riders who run cold.
When merino works better
The Women's ARC Merino Long Sleeve Base Layer blends merino with synthetic fibers for stretch and durability. It naturally resists odors and regulates temperature, keeping you comfortable from start to finish. However, its long sleeve design and thicker fabric mean it's not the first choice for scorching summer rides.
Trade-offs at a glance
- Cooling performance: Mesh (Pro Air) actively pulls sweat and maximizes airflow for rapid evaporation. Merino (ARC) adjusts to your effort, keeping you cool as intensity rises but with less direct airflow.
- Versatility: Merino works well from cool mornings to warm afternoons. Mesh is specialized for hot days and sustained efforts where staying dry is critical.
- Fit and feel: The Pro Air is cut for a performance-led, close-to-skin fit that sits cleanly under a jersey. The ARC merino blend adds stretch and is exceptionally soft against the skin.
Product facts
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Pro Air Short Sleeve Base Layer II: An updated all-over open mesh fabric draws sweat away from the skin quickly while promoting airflow. This helps you stay dry and focused on hot, high-output rides by maximizing evaporation.
Pro Air Short Sleeve Base Layer II
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Womens ARC Merino Long Sleeve Base Layer: Made from a premium merino blend from Italy's Biella region, it naturally regulates temperature and is fast-wicking and odor-resistant. You get versatile temperature control and freshness across a broader range of conditions, not just hot weather.
Womens ARC Merino Long Sleeve Base Layer
Which one fits you?
Best for
- Riders who prioritize maximum cooling on hot, high-output rides
- Cyclists who want a lightweight, fast-drying base layer for summer
Not for
- Riders who need a base layer for cool mornings or variable conditions—choose merino instead
- Those looking for a long sleeve option—the ARC is the only long sleeve here
