Winter Base Layers

Black Friday Everything at -60% | The role of the winter base layer in your layering system

Worn directly against the skin, the winter base layer forms the foundation of any cyclist layering system: a first layer, an insulating jersey, then a windproof jacket on the outside. Its role is twofold: wick away the moisture generated by effort to the outside and stabilize your body temperature, even during stops or downhill sections where cooling is fastest.

Unlike a classic long-sleeve jersey designed as a standalone outer piece, the base layer has a close-to-the-body fit and a technical fabric entirely dedicated to moisture management rather than aesthetics. It works just as well under a long-sleeve jersey as under a winter skinsuit, without ever creating an uncomfortable extra layer.

Merino wool or synthetic fibers: which material should you choose?

Merino wool offers natural thermoregulation and valuable odor resistance over several consecutive rides, while technical synthetic fibers dry faster and are more budget-friendly. Both materials share the same mission: keep the skin dry at all times.

For long or repeated rides without washing between uses, choose merino. For regular use with easy care, synthetic fibers are more than enough.

Long sleeves, short sleeves, or sleeveless: which cut for your riding style?

The long-sleeve winter base layer remains the benchmark for bitter cold, covering the entire arm down to the wrist. Short-sleeve or sleeveless versions suit milder temperatures, worn as an extra layer under a long-sleeve jersey without too much heat buildup. A high collar or integrated hood provides extra protection for the neck area, often the first to be exposed to the wind.

The choice of cut also depends on your discipline: road and gravel rides call for a close-fitting cut under an aerodynamic setup, while mountain biking and winter running favor greater freedom of movement at the shoulders.

Choosing the right setup according to the season and effort intensity

The ideal thickness depends as much on the outside temperature as on the intensity of your effort: a hard tempo creates far more body heat than an easy endurance ride, which is why you should adjust the base layer weight accordingly.

This logic applies just as well to long winter distances in ultra distance, as to daily commutes in urban riding, where frequent stops expose you more to chilling.

Care and lifespan of your thermal base layer

Wash your winter base layer at low temperature, without fabric softener: fabric softener clogs technical fibers and permanently reduces their breathability and moisture-wicking performance. Air-drying away from direct heat helps preserve the fabric's elasticity over time.

For a full cold-weather setup, pair it with a thermal jacket, autumn-winter gloves and winter shoe covers to leave no extremity exposed. Replace the base layer as soon as the fabric loses its elasticity or insulating power, a sign that its thermal efficiency has dropped.