Men's Blue Bike Baselayers

For hot summer rides sleeveless baselayers with perforated, ultra-lightweight mesh maximize ventilation and pair well under a jersey; Pearl iZumi's Transfer Mesh Sleeveless is designed for that purpose. Short sleeves work for mid-season layering, while long sleeves use midweight brushed fabric to add insulation against wind and cool temperatures.

A snug, second-skin fit is best for moisture wicking because it keeps fabric against the skin without excess material. Look for high-stretch constructions with about 15% elastane and seamless panels or flatlock stitching so you retain mobility in aggressive riding positions.

Merino wool—often fine at about 18.5-micron fibers—offers natural odor control and temperature regulation, while synthetic polyester and nylon dry faster after heavy use. Blends that put polyester on the skin side and wool on the outside, like the Pearl iZumi Merino Baselayer, balance quick wicking with odor resistance.

Quarter-zip and half-zip styles let you dump heat quickly on long climbs by opening the neck and increasing airflow. Several cooling systems, such as PRO Transfer Mesh with In-R-Cool, pair well with zips, and models like the Endura Translite II use open recycled polyester mesh to boost mid-ride ventilation.

Seamless construction and flatlock stitching reduce friction where your body contacts a jersey in dropped positions. High-stretch mesh, open-hole panels that lift the jersey off the skin, and blends with elastane all help maintain comfort during long rides.