Whatever the weather, most cyclists choose to wear a base layer.
In the winter, a heavier weight long sleeve base layer adds essential extra protection from the cold. There’s greater debate as to whether you should still wear a base layer in the summer, although UK temperatures rarely get so hot that it’s a problem if you do. A base layer can aid wicking performance too, helping to keep you more comfortable both in hot and cold conditions.
Here, we’ve rounded up our pick of the best base layers for both summer riding and when it gets cooler. Of course, the weather isn’t either hot or cold, so we have options that will work as well in between, under an appropriate winter cycling jacket or long sleeved or short sleeved jersey. Lower down, we’ll tell you how to choose.
Our pick of the best cycling base layers
Summer base layers
- Assos Summer NS Skin Layer P1: RRP £65
- Castelli Pro Mesh 2.0 Base Layer: RRP £55
- Le Col Pro Air Base Layer II: RRP £55
- Rapha Merino Lightweight Base Layer: RRP £65
- Sportful Pro Baselayer Tee: RRP £50
Winter base layers
- Castelli Medio: RRP £80 – read our full review
- Le Col Arc Merino Thermal: RRP £75 – read our full review
- Lusso Paragon Deep Winter: RRP £65 – read our full review
- Maap Thermal LS Tee: RRP £75 – read our full review
- Sportful Merino Layer Tee: RRP £90 – read our full review
Why trust Cyclist‘s advice?
Come hot or cold, we’re out riding here at Cyclist to bring you our big rides and classic climbs, along with our detailed reviews of bikes, gear and all things cycling, both in Cyclist magazine and online.
A base layer is an essential piece of kit to pack, whether we’re heading for an Alpine col or the heat of Colombia. We know our cycling base layers and have selected our top picks here. We’ve not paid for product placement or for our reviews, so you can trust Cyclist for unbiased advice.
The best summer base layers
Assos Summer NS Skin Layer P1
£65 | Buy here
With a weight of just 42g for a size L, the Assos Summer NS Skin Layer P1 is low in weight for hotter days, with Assos rating it for temperatures over 21C. It has a seamless body with a knitted-in bottom hem and raw-edged armholes. Its carbon fibre containing fabric has a pique weave and is said to be quick drying, while the carbon content is claimed to offer permanent odour resistance. There are three sizes for both men and women.
Castelli Pro Mesh 2.0 Base Layer
£55 | Buy here
Castelli says its open mesh base layer is good for temperatures between 15C and 28C, helping to wick away sweat. Weighing around 100g and with a lay-flat bottom hem, it shouldn’t notice even under the lightest summer kit. There are plenty of colour options, four for men and three for women, and a good size range, both with and without sleeves.
Le Col Pro Air Base Layer II
£55 | Buy here
With an updated collar, improved fit and more open mesh than the original, Le Col says that version two of its summer base layer offers even better performance in hot weather. It’s another base layer that can be bought both with and without sleeves, with a good range or sizes for both male and female riders. White or navy blue options add to the available choices.
Rapha Merino Lightweight Base Layer
£65 | Buy here
This Rapha base layer includes 55% merino wool, which should increase its odour resistance and ability to soak up sweat. There are sleeved and sleeveless options and no less than five colour choices. Rapha promotes the merino content’s contribution to the base layer’s comfort too, while flatlocked seams avoid rubbing and a Rapha tag at the collar adds a little style.
Sportful Pro Baselayer Tee
£50 | Buy here
Sportful’s all-synthetic base layer has a ribbed knit structure that it claims provides internal channelling and improves breathability and sweat management. There’s a broad range of sizes and a sleeveless option available, with Sportful rating its base layer for temperatures up to 30C, making it a good option for the hottest days.
The best winter base layers
Castelli Medio long-sleeve base layer
£80 | Buy here
Castelli’s polyester base layer has the warmth for cool to cold rides, although there’s no elastane in the weave, so the fit is a little less close than other options. If you do need to open up your jacket’s collar, the low-cut neckline can leave a bit of a chill, though there’s a soft hand, making it comfortable next to the skin. It manages sweat well, not becoming damp or clammy and it’s reasonably resistant to odour.
Le Col Arc Merino Thermal long-sleeve base layer
£75 | Buy here
Le Col rates its base layer down to zero degrees, principally thanks to the warmth provided by the 65% merino content. It performs well if you do warm up, staying comfortable and wicking away moisture and it’s quick drying. The merino content avoids odour and flatlocked seams also help keep you comfortable.
Lusso Paragon Deep Winter base layer
£65 | Buy here
For the coldest rides, Lusso’s built-in neck warmer helps to protect you and can be rolled up to cover your nose and ears if needed. The all-synthetic Polartec Power Grid fabric has deep flocking to the inside to help trap insulating air and increase warmth. It’s odour-resistant and would do duty for other cold weather sports and outdoor activities, not just cycling.
Maap Thermal LS Tee base layer
£75 | Buy here
Maap makes its base layer of the same Polartec Power Grid fabric as Lusso, but has chosen a lighter fabric weight that’s better for warmer temperatures. As with the Lusso base layer, gridded internal face insulation helps increase warmth. It’s a closer fit than the Lusso too, which along with the synthetic fabric ensures good moisture management. As with the Castelli Medio, the collar is quite low, so any draughts around the collar will be felt.
Sportful Merino Layer Tee long-sleeve base layer
£90 | Buy here
Sportful’s base layer has a higher collar to add extra insulation at the neck and includes 30% merino wool adding to the warmth on offer, as well as assisting the good wicking performance. Its cuffs are adequate in length, but the body is a little short and can leave cold spots, although it should be long enough to overlap with bottom half winter clothing.
Read our full Sportful Merino Layer Tee long sleeve base layer review
How do I choose the best base layer for cycling?
Fabric composition
Most base layers include at least some synthetic yarns, usually either polyester or polypropylene. Nowadays, it’s often recycled. That’s usually, but not always, combined with elastane/lycra to add stretch.
The wildcard in the mix is merino wool, usually as a mix with synthetics, but occasionally used on its own. Depending on the weave, it can add warmth, but it can also improve wicking performance in summer base layers and works well to absorb sweat. It inhibits bacterial growth and the associated odour too, making it a good option for multi-day trips. All-synthetic pieces are much less prone to get smelly than they were a few years ago though.
Insulation – or not
Depending on the weather, you may be looking for insulation. A base layer worn under a winter jacket or a cycling gilet is an essential for warmth when it’s cold. The outer layer needs to add windproofing for the insultation to be effective. Look for good coverage of the torso and arms, a high neckline and enough length for overlap with bib tights.
Once the temperature rises above, say, 15C you’ll probably want to swap to a summer base layer. Now, the requirement is for airflow to keep you cool, so look for a low weight piece with an open weave, maybe without sleeves.
Wicking
In both cases, a key function of a base layer is to wick sweat away from your skin, either to stop you from getting chilled in the winter, or to spread out the moisture and help it evaporate to keep you cooler in the summer. Technical weaves help to move the sweat from the inner face to the outer layer of the base layer.
Be careful to wash your base layer in specialist detergent to help retain its performance and never use fabric conditioner. Standard laundry products contain wetting agents, optical brighteners and other additives that can degrade the wicking and may also cause elastane to lose its stretch over time.