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Base layers in the height of summer? To many cyclists, that sounds like a sauna in the saddle. In fact, a suitable functional base layer can have exactly the opposite effect in high temperatures: better moisture wicking, faster sweat evaporation and, as a result, greater cooling. We’ll show you what to look for when buying a summer base layer and introduce the best functional base layers for road bikes, MTBs and gravel bikes.
Modern functional base layers for hot days are not designed to keep you warm, but rather to quickly wick sweat away from the skin, distribute it over a wide area and thus aid evaporation. Particularly on long rides, during high-intensity activities or in the mountains, a lightweight mesh base layer can noticeably improve your skin’s microclimate and prevent your jersey from sticking to your skin when it’s soaking wet.
But not all base layers are the same. The material, fabric structure, fit and intended use determine whether a base layer actually keeps you cool or acts as an extra layer of warmth. For the height of summer, we would particularly recommend Extremely lightweight mesh base layers ... The decisive factor is not so much the brand as the combination of open mesh structure, low weight, high breathability and a close-fitting cut. This is the only way to efficiently wick sweat and heat away from the skin.
1. Assos Summer NS Skin Layer P1
The ASSOS Summer NS Skin Layer P1 is an ultra-lightweight, sleeveless performance base layer for hot summer days on the bike. The breathable mesh fabric ensures effective moisture management, a cooling airflow and a high level of comfort against the skin. Thanks to its close-fitting, second-skin fit, it is ideal as a base layer under modern performance cycling jerseys.
Information & Price
- Sleeveless base layer for warm temperatures from around 21 °C
- 15 per cent lighter than the previous version
- Very high breathability (5/5)
- Cooling, open-weave mesh fabric
- Stretchy, second-skin fit for optimal layering
- Long-lasting odour-inhibiting properties thanks to carbon fibres
- Quick-drying and can be packed away to take up very little space
- Material: 68% polypropylene, 29% polyamide, 3% carbon fibre
- Price: 75.00 euros >> available here
2. Castelli Core Mesh 3 Sleeveless
The Castelli Core Mesh 3 Sleeveless is an ultra-lightweight mesh undershirt for hot summer days. The open mesh fabric ensures maximum ventilation, quickly wicks sweat away from the skin and creates a layer of air between the body and the jersey for an additional cooling effect.
Information & Price
- Castelli’s lightest and most breathable base layer
- Open-weave mesh fabric for maximum breathability
- Rapid moisture-wicking for a dry, comfortable feel
- Helps with evaporative cooling in high temperatures
- Keeps the jersey away from the skin and improves airflow
- Comfortable stretch fit thanks to the elastane content
- Material: 90% polyester, 10% elastane
- Price: 45.00 euros >> available here
3. Craft Pro Dry Nanoweight
Our personal insider tip as Ultra-lightweight base layer for mountain biking and road cycling. The Craft Pro Dry Nanoweight SL W is an extremely lightweight, sleeveless performance base layer designed for intense training sessions and hot weather. The fine mesh fabric ensures excellent temperature regulation, rapid moisture-wicking and a pleasantly cool feel against the skin.
Information & Price
- Ultra-lightweight mesh base layer for high-intensity activities and warm conditions
- Excellent moisture-wicking properties to keep you dry
- Cooling properties for optimal temperature regulation
- Close-fitting, tight-fit cut
- Weight-saving, taped design elements
- High proportion of recycled polyester
- An exceptionally lightweight material weighing just 80 g/m²
- Material: 48% polyester, 39% recycled polyester, 13% elastane
- Price: 44.95 euros >> Available here at a reduced price
4. Odlo Performance X-Light Base Layer Tank Top
The Odlo Performance X-Light Base Layer Tank Top is an ultra-lightweight functional base layer designed for intense activities in high temperatures. The highly elastic fabric aids active temperature regulation, quickly wicks moisture away from the skin and ensures you stay comfortably cool and dry, even on hot days.
Information & Price
- Ultra-lightweight base layer for hot conditions and intense physical activity
- Active temperature regulation for an optimal body temperature
- Excellent moisture-wicking properties for a dry, comfortable fit
- Seamless design to prevent points of friction
- Highly elastic material that feels like a second skin
- Extremely breathable and quick-drying
- Material: 27% polyamide, 73% polyester (recycled)
- Price: 39.95 euros >> Available here at a reduced price
5. GripGrab Ultralight Mesh Sleeveless Base Layer
The GripGrab Ultralight Mesh Sleeveless Base Layer has been specially designed for hot summer days. The open-mesh fabric ensures maximum ventilation, effectively wicks sweat away from the skin and keeps the body comfortably dry even during intense rides. Thanks to its light weight and close-fitting design, it is barely noticeable under a cycling jersey.
Information & Price
- Ultra-lightweight summer base layer for temperatures above 20 °
- Open mesh structure for maximum breathability
- Excellent moisture-wicking properties for a dry, comfortable feel
- Close-fitting cut (‘Next-to-Skin Fit’)
- Minimal weight and thin material under the jersey
- Polygiene® anti-odour treatment for long-lasting freshness
- Ideal for road cycling, gravel cycling and mountain biking in the height of summer
- Material: 94% polyester, 6% elastane
- Price: 35 euros >> Available here at a reduced price
6. Icebreaker 75 Featherlight™ Tank Top
The Icebreaker 75 Featherlight™ Tank Top is Icebreaker’s lightest and most breathable base layer. The innovative Cool-Lite™ fabric blend of merino wool and TENCEL™ Lyocell ensures effective cooling, rapid moisture-wicking and a high level of comfort during intense activities and in warm temperatures.
Information & Price
- The lightest base layer in the Icebreaker range
- Cool-Lite™ fabric for optimum cooling and breathability
- Quick-drying fabric for a dry, comfortable feel
- Natural merino wool content for odour control
- Extremely lightweight at just 67 g (size M)
- A cut designed for ease of movement, with side panels
- Offset shoulder seams for maximum comfort when wearing a rucksack or straps
- Material: 80% TENCEL™ Lyocell, 20% merino wool
- Price: 79.95 euros >> Available here at a reduced price
Conclusion: Which base layer is best for hot days?
If we had to choose just three candidates for the height of summer, they would be the Assos Summer NS Skin Layer P1, the Craft Pro Dry Nanoweight and the Castelli Core Mesh 3 Sleeveless. They do exactly what a good Base layers for the summer It should offer: as little fabric as possible against the skin, maximum breathability, efficient moisture-wicking and a jersey that doesn’t cling to the body like a wet rag, even after hours in the saddle.
Anyone who has a Base layers for temperatures above 30 degrees, whether you’re looking for intense road cycling rides or gruelling MTB tours, these models currently offer some of the most compelling options on the market.
Stefan Frey
Editor