Unparalleled in its versatility, this packable mid layer goes on offense in the cold—boosting thermal protection around your core and upper arms with its insulating OSMOS Heavy fabric.
It’s no accident this short-sleeve “Thermobooster” mid layer resembles an aero jersey. By mirroring its silhouette, adding a full-length zipper, and including a pocket that doubles as a storage pouch, we’ve created a super versatile second layer that boosts thermal insulation around your core and upper arms, yet disappears in a rear pocket when things warm up. In fact, we’ve added a dedicated Thermobooster storage sleeve into the johDah Winter Jacket for this exact reason, allowing you to enter your winter training rides fully prepared for fluctuating weather and drastic changes in elevation.
Layered directly above your Skin Layer, the Thermobooster traps body heat, breathes, and expels excess moisture using our OSMOS Heavy textile. This is the thickest of our brushed-back fabrics, featuring a stretchy warp-knit composition that smoothly wraps your torso and upper arms for a full-on fortress against the cold. The raw-cut hem and reversed zipper smoothly integrate with layers above and below, ensuring your complete outfit system remains as streamlined as possible.
OSMOS Heavy: This warp-knit is the main textile and the heaviest in our brushed OSMOS family (290g/m2), featuring asymmetrical stretch and a soft, durable construction. High levels of insulation are derived from the brushed skin-facing side.
Ramp Pocket: A single textile-lidded pocket doubles as a storage pouch.
Reversed Zipper: Full-length zipper, reversed for a smooth action and clean integration with outer layers.
Taped Neck: Frictionless comfort next to the skin, aided by a microfiber zipper garage.
Raw Cut: Hem is raw cut, creating a smooth, aerodynamic design that seamlessly pairs with additional layers.
raceFit: A second-skin fit that’s tighter and more compressive than our regularFit, engineered for high-output, drag-free riding and racing.
Composition: 56%PA 28%PL 16%EA