Assos Endurance ThermoBooster

The Assos Endurance ThermoBooster adds adaptable warmth to cycling and cross-training kit, moving from an outer layer in cool weather to an insulating midlayer when conditions turn colder. Its simplified design uses one textile and one zipper, making it easy to build around the clothing already suited to the ride.

The Roubaix-style RX textile provides soft thermal insulation with a highly elastic, low-volume structure. It holds warmth close to the body while remaining flexible enough to sit comfortably above a jersey or beneath a jacket. The regularFit silhouette follows the body's contours, with fewer seams to reduce friction between the rider and overlapping layers.

Raw-cut finishing removes bulky hems and raised edges for a cleaner profile. This race-inspired construction keeps the garment streamlined and helps it fit smoothly into a broader kit setup. The emphasis is on useful insulation and uncomplicated layering, with a fit that supports long-distance comfort rather than restricting movement.

In cool conditions, or on a long alpine descent during summer, the ThermoBooster layers over a standard jersey for additional warmth. Beneath a rain shell, it provides insulation while the outer garment handles wet weather. In severe cold, it sits under a winter jacket. Its broad temperature range reflects these different combinations rather than standalone protection across every condition. The recommended range is 17.6 to 68.0°F, depending on the surrounding layers.

The ThermoBooster also works beyond cycling as an insulating layer for cross-training. Its value lies in the ability to adjust a familiar clothing system: add warmth where needed, keep bulk controlled, and select the outer protection appropriate to the weather.

Key Features

• Adaptable Thermal Layer - Wear over a jersey for cool rides or beneath a rain shell or winter jacket as conditions demand.
  
• Soft RX Insulation - Elastic Roubaix-style fabric provides midweight warmth without excessive bulk between layers.
  
• Smooth, Streamlined Fit - Body-contoured regularFit shaping and raw-cut finishing reduce seams and raised edges for comfortable layering.