Nobody can see you're wearing one, but a good cycling base layer can make the difference between being comfortable and being cold and clammy, especially in the winter.

A cycling base layer, as the name suggests, goes under your other clothes, against your skin. But what’s wrong with just wearing a jersey?

Well, for starters, the classic ‘layering’ combination of base layer, jersey and jacket is versatile. You can switch and swap according to the conditions. You can fine tune the base layer itself and more or less leave everything else alone: a warm base layer for cold weather, and a light one for summer will work equally well with the same top.

A baselayer's an essential part of your outfit if you're going to ride in conditions like this. Image by Vik Banerjee via Flickr.

Base layers are made from fabrics that are designed to move sweat away from the skin. That’s important in summer, when they can help keep you cool and dry, but it’s even more important in winter. When you sweat your way to the top of a hill then stop for a breather, a cotton t-shirt will have you feeling cold and clammy very quickly. A good base layer will hold so little water against your skin that you’ll still be comfortable.

Base layers split into two varieties: synthetic and merino. Synthetics are usually lighter and a bit cheaper to buy, but can feel a bit, well, synthetic. Merino is a type of wool, with very fine, soft fibers so it’s comfortable against the skin. Both synthetic and merino base layers retain their insulating properties when they get damp from sweat, but merino has the advantage of being naturally antibacterial thanks to the lanolin in the wool, and the structure of the wool fibre.

As a result, merino tends to resist getting smelly even if you don’t wash it between rides, as it’s the bacteria that live off your sweat that smell, not the sweat itself. Synthetic base layers have coatings on the fibres to prevent bacterial growth and pong, but these tend to wear off over time.

The base layers below have been selected to give you an overview of what’s available, and we know from experience they’re all well made and work well.

We’re not saying they’re the only ones you should consider, though. Companies such as Assos, Castelli, Endura, Exteondo, Helly Hansen, Louis Garneau, Nzo, Odio, Pearl Izumi, Santini, Solo, Sportful, Under Armour and plenty of others make good base layers.

Got a favourite? Let us know in the comments.

Rapha Merino

rapha

Yes, it’s a product of up-themselves roadie uber-brand Rapha (“drinking coffee, looking tired"), and yes it’s expensive, but Rapha’s merino baselayers deserve their reputation for being fantastically comfortable.

The fabric is feathery-light and silky smooth, the fit is long and close and Rapha’s claims of the same garment being able to wick away sweat and keep you warm when it’s cold are right on the money.

From: Rapha

Price: £60

Craft Active Crew Neck Long Sleeve Base Layer

Craft

There’s a high collar to keep your neck cosy because cold there is literally a pain in the neck, and a long tail to keep your lower back covered.

From: Craft

Price: £32

Northwave Karbon Tex

Northwave

Making it even cosier and more effective in very cold conditions, a wind-resistant layer on the front stops the chill from getting through.

It's overkill if the temperature is above single figures, though, unless you enjoy being a boil in the bag rider.

From: Northwave; i-ride.com

Price: £55.99

dhb Merino SS Roundneck Baselayer M_150

Picture 43978

We like short-sleeve merino shirts for cool (rather than frigid) days, and even as undershirts when it gets a bit warmer. They’re perfect for early starts on Spring and Autumn rides.

From: Wiggle

Price: £27.89

DeFeet Un-D-Shurt Short Sleeve Base Layer

Defeet

It’s thin enough to fit under just about anything, though if you want something even lighter for summer rides, take a look at DeFeet’s barely-there Un-D-Lite base layers.

From: DeFeet, i-ride.co.uk

Price: £35.99

Gore Bike Wear Windstopper Turtleneck

Gore

The zip neck makes for a little versatility as it’s rarely consistently cold enough for you to be fully snugged up in base layer like this for both climbing and descending.

From: Gore Bike Wear

Price: £74.99

Marmot Midweight 1/2 Zip LS

Marmot

It’s made from Polartec Power Dry, a polyester/Lycra mix with Cocona activated charcoal impregnated in the fibres to help control pong. The Lycra helps make it snug without being super-tight and the fabric is thick enough that with another layer or two it works for everything from cool Spring and Autumn days to the depth of winter.

Because it’s intended for outdoors rather than bike ride use, the back’s not as long as some, but the whole shirt is plenty long enough that you won’t get a cold lower back as long as you’re not in a racing snake ride position.

From: Marmot

Price: £54.99