How to Dress in Layers – Layer 1: Base Layer (Perspiration)
INONI Cycling Clothing System Layer 1
Layer One: Base Layer
The foundation of every cycling outfit. Without it, no jacket or outerwear will function properly. Learn the basics of layering and how to choose the right sweatshirt for the temperature and activity.
3
system layers
4
types of underwear
-20°C
up to +30°C range
Why is base layer underwear key to comfort?
While cycling, the body can produce up to several liters of sweat per hour. Wet skin under a cycling jersey is a recipe for hypothermia, chafing, and discomfort—especially when the temperature drops or the wind picks up. Base layers, or sweatbands, act as an intelligent membrane: they wick moisture away from the skin, maintain proper body temperature, and protect against chafing.
The better the first layer, the better the others will perform. Even the most expensive membrane won't help if you have a cotton T-shirt underneath that traps moisture. That's why choosing a sweatshirt is the first and most important step in putting together your cycling kit.
The golden rule of the layering system:
Layer 1 (underwear) – wicks away moisture. Layer 2 (insulation) – retains heat. Layer 3 (jacket) – protects against wind and rain. Each layer has its own purpose and must work in conjunction with the others.
Three-layer system
1
Layer
Base layer underwear
Moisture wicking Dry skin Temperature regulation
ACTIVE
2
Layer
Insulation
Keeps you warm Merino / Primaloft Sweatshirt For cold days
THERMAL
3
Layer
Security
Protects against wind. Keeps rain away. Jacket or gilet.
PROTECTIVE
This article focuses on layer 1. We cover layers 2 and 3 in subsequent parts of the series.
Four types of INONI base layers
INONI offers base layers in four material versions, each designed for different temperature conditions and intensity of exercise.
COLD
HOT
-10°C 0°C +10°C +20°C +30°C
Type 1A
Polypropylene – sleeveless
The lightest, summer heat
+15°C to +30°C
Summer
Type 1B
Polyamide with carbon – long sleeve
Black, carbon fiber, all-season
+5°C to +30°C
Spring-Summer
Type 2
Primaloft – thin
Autumn and cold spring
-5°C to +15°C
Autumn–Spring
Type 3
Merino – natural wool
Winter, bikepacking, expedition
-10°C to +15°C
Winter–Spring
1
Polypropylene and polyamide sweatband - rapid moisture transport
+5°C – +30°C Summer Intense effort All disciplines
INONI offers two types of classic synthetic sweatbands. The white polypropylene sweatband is the lightest option – an ultra-soft knit that quickly wicks away sweat and is virtually invisible under a shirt. The black polyamide sweatband with carbon fibers contains carbon fibers that have bacteriostatic properties, neutralizing unpleasant odors even after long rides. Both models are suitable for multi-day bikepacking trips.
The lightest sleeveless sweatshirt made of polypropylene – perfect for summer and multi-day trips. The ultra-soft fabric instantly wicks moisture away from the skin. The white color is invisible under a t-shirt. It's perfect for both short rides and long bikepacking expeditions.
This black polyamide sweatshirt with carbon fibers is bacteriostatic and resistant to odors. Its long sleeves protect against cold air during descents or cool mornings. Carbon fibers neutralize bacteria, so it can be worn for several days without washing. Perfect for multi-day bikepacking expeditions.
Classic white long-sleeved underwear. The white color is discreet under light-colored cycling jerseys. It wicks away moisture and protects your arms from getting cold on cooler mornings or descents.
Primaloft is a revolutionary, ultra-thin synthetic fiber originally developed for the US military as an alternative to down. For cycling, it's perfect as a base layer during the transitional seasons. It's featherlight yet surprisingly warm. Unlike down, it retains its insulating properties even when wet.
Primaloft INONI underwear is available in sleeveless (with straps) and short-sleeved versions. The sleeved version is perfect for keeping your core warm while still allowing your arms to breathe. The sleeved version adds insulation when temperatures drop below 5°C.
Primaloft as insulation for rest stops
On long bikepacking trips, Primaloft underwear is great for rest stops and overnight stays. During the day, you ride in just sweat, and when you stop or the temperature drops, you add Primaloft under your jacket or sweatshirt.
Ultralight underwear made of thin Primaloft on the shoulder straps. It insulates the core while leaving the arms completely free. Perfect as an extra layer on cooler mornings or during layovers. Surprisingly lightweight, it packs down to fit in a jersey pocket.
The short-sleeved version offers maximum insulation with minimal weight. Ideal when temperatures drop below 5°C and you want warmth throughout your torso and arms. Perfect as a first layer under a winter jacket or Primaloft sweatshirt.
Merino wool is one of the greatest textile paradoxes: a natural material that outperforms most synthetics in terms of performance. Merino fibers are so fine (less than 20 microns) that they don't itch or chafe—they can be worn next to the skin. Body temperature is automatically regulated: insulating in cold temperatures, wicking away moisture in hot temperatures.
For cyclists, the most important property of merino wool is its resistance to unpleasant odors. Merino wool can be worn for several days in a row without washing and still remain fresh. This is crucial for multi-day bikepacking trips when frequent washing is not possible.
The perfect choice for cold days, winter training, and multi-day bikepacking expeditions. This merino wool jersey combines thermal performance, antibacterial properties, and exceptional comfort. You can ride in it in the morning at 0°C and return in the afternoon at 12°C—and still feel comfortable.
Tested by road cyclists, gravel cyclists, and bikepackers, it's the perfect choice for cold days when you need a warm base layer that doesn't restrict movement or cause overheating during exercise.
Choose underwear that suits the temperature and type of activity
Underwear
Temperature
Season
Effort
Multi-day
Polypropylene without sleeves
+15°C – +30°C
Summer
Tall
✅
Polyamide + carbon long sleeve
+5°C – +30°C
Spring-Summer
Tall
✅
Primaloft (straps/crotch)
-5°C – +15°C
Autumn–Spring
Medium–High
✅
Merino (wool)
-10°C – +15°C
Winter–Spring
Low–Medium
✅✅
Practical advice - frequently asked questions
Is base layer underwear necessary in summer?
Yes, especially on longer rides. In hot weather, moisture management is even more important. A sleeveless polyamide sweatband keeps your skin dry and prevents chafing from your cycling jersey. Without it, a wet jersey sticks to your skin and causes discomfort.
Can I use cotton underwear?
No, cotton is a mistake. Cotton absorbs sweat and holds moisture close to the skin. Wet cotton on cool days can lead to hypothermia, even on relatively warm evenings. Cycling rule: Cotton kills comfort.
How to wash cycling underwear?
Polyamide: wash at 30°C on a gentle cycle, without fabric softener (this will damage the water-repellent properties). Merino: wash at 30°C on a gentle cycle or by hand. Do not iron or tumble dry. Turn inside out before washing.
How many sets of underwear for a bikepacking trip?
The rule of three: one on, one dry in the bag, one in the wash. Merino underwear allows you to wear it for 2-3 days without washing, which reduces the amount of luggage you need. For shorter trips, 2-3 reels of polyamide or 1-2 merino are sufficient.
Series: How to Dress in Layers
Ready for more layers?
The first layer is ready. In the next installments of the series, we'll describe INONI cycling jerseys and jackets – the second and third layers of the system.
