Assos - Endurance Thermo Booster - Men's - Black Series - 2026

Assos - Endurance Thermo Booster - Men's - Black Series

The Endurance Thermo Booster is the ultimate midweight layer, designed for total versatility across all seasons. With one textile and one zipper, it provides adaptable thermoregulation whether worn over a jersey, beneath a rain shell or layered under a winter jacket. From cool summer descents to the harshest winter conditions, this piece keeps your core temperature stable without excess bulk. 

Engineered with RX textile, it delivers soft, midweight insulation in a low-volume, highly elastic fit that makes it ideal for layering. In mild or transitional weather, it functions as a standalone thermal layer, while in deep winter it boots insulation beneath outer shells and jackets. Finished with raw-cut construction for a clean, aerodynamic silhouette, the Thermo Booster combines simplicity with true four-season performance.

Key Features:

Featured Fabrics:

• RX Textile is Assos' most versatile Roubaix-style thermal fabric, providing soft midweight insulation, stretch and breathability. 

Construction & Fit

• A regularFit is streamlined, body-contoured fir that reduces seams for frictionless comfort and easy layering. 
• Raw-cut edges that eliminates hems and ridges for low-bulk layering and race-inspired aerodynamics. 

best For

• Cool spring and autumn rides.
• Summer alpine descents.
• Wet or cold conditions layered beneath a rain shell or winter jacket.

About ASSOS:

ASSOS of Switzerland’s mission is to provide innovative, technically outstanding cycling apparel with meticulous, lean design.

Since creating the first ever Lycra® cycling shorts in 1976, the company has developed a number of innovations that have pointed the way for the evolution of cycling wear – most of its innovations are now industry standards. Today, ASSOS proudly provides its Total Cycling Comfort to riders in more than 30 countries.

MyTriathlon is proud to have been chosen to stock the prestigious ASSOS range of clothing and accessories. If you have any sizing or specific product queries, call us on 0207 183 4116, or get in touch via WebChat.