The ultimate guide to nailing your base layer
There’s a moment every cyclist knows. You leave home with what seems like the perfect outfit and, twenty minutes later, you realize something isn’t right. Either you overheat too quickly, or you get cold too soon. Instinct tells you to blame the outer garment—the jacket, the jersey, the vest—but in most cases, the real story starts much closer to the skin.
The first layer you choose determines your entire thermal experience. The base layer is the silent element of any kit, in both winter and summer. It manages moisture, stabilizes body temperature, and prevents the sudden changes every cyclist knows well. When the base layer is wrong, everything feels wrong. When it’s right, you barely notice it: you just feel comfortable.
An undershirt doesn’t exist to keep you warm. It exists to regulate you. That’s why it’s the most important garment in both cold and warm conditions. It manages sweat so it never becomes a cold sensation. It maintains a stable cushion of air close to the skin. It insulates from the cold without retaining excess heat. And in summer, it transports sweat faster than bare skin, keeping you dry even as temperatures rise. The first layer sets the tone for the entire ride.
How the body really perceives temperature
Understanding thermal sensation means going beyond the number on a weather app. Real comfort depends on the climate, the intensity, and the garments you wear directly on your skin. Cold wind steals heat and requires reinforcing the outer layer, not adding more inner layers. Humidity changes everything, as it drastically alters the thermal perception, and the base layer protects you from that imbalance.
Effort matters too. A relaxed flat ride is nothing like an intense climb. The higher the intensity, the less insulation you need. But you do need a base layer capable of moving sweat before it cools on your skin. And the base layer itself is a decisive factor: a thin technical layer regulates without adding extra warmth. Merino wool adds natural insulation and excellent moisture management. Riding with no base layer only works in real heat; in the cold, discomfort appears very quickly.
The mistake all cyclists make in winter
That’s why the most common mistake in winter is overdressing. Many cyclists tell us that a jacket designed for five or ten degrees feels too warm, and when we analyze the combination, we discover two base layers or even a thermal jersey underneath. There’s no airflow or escape for moisture. Sweat accumulates, the sensation of heat rises quickly, and then the inevitable chill arrives when that moisture cools. More clothing doesn’t protect you: it breaks your thermal balance.
How to choose the right combination every time
Even so, there are simple principles that almost always work:
- If humidity is high, choose a base layer with excellent sweat management, whether merino or technical.
- If the wind is cold, reinforce the outer layer, not the inner one.
- If you expect an intense ride, reduce insulation and prioritize breathability.
- If the ride will be easy, choose a warmer base layer, but avoid unnecessary layers.
In most situations, a single base layer combined with the right jersey or jacket is enough.
Recommended combinations for real conditions
These principles take shape in combinations designed for the most common scenarios and help any cyclist choose with confidence.
18º – 30ºC | Warm summer
- Ultralight base layer. SECOND SKIN.
-
Any summer jersey.
10º – 17ºC | Windy conditions
Easy pace
- Thin technical base layer LIMBER SKIN.
- Winter jersey HYDER.
- Thin windbreaker jacket SELKIE, ENVY.
Medium/High pace
- Thin technical base layer such as CELL SKIN.
- Mid-season jersey VANQUISH, AVALON.
- Windbreaker vest PLUS, VECTOR, EMINENT.
0º – 10ºC | Dry cold
Easy pace
- Thick base layer WINTER MERINO.
- Thermal jacket ARMOUR,
Medium/High pace
- Thick base layer WINTER MERINO.
- Highly breathable thermal jacket SKIMO PRO
-8º – 5ºC | Wet/Rainy
- Thick base layer WINTER MERINO.
- Waterproof jacket EXO, SUPERARMOUR.
The foundation of every good outing
Thermal comfort is not a fixed temperature range. It is the result of a conscious approach to the layering system and understanding how the body responds to exertion, wind, and humidity. The base layer is the starting point of any well-planned outfit and the garment that allows all the others to function as they should. When you choose it well, the whole ride simply feels right.
