Guide to cycling base layers

Your base layer is the layer sitting closest to the skin. It should fit like a second skin – a fairly snug, close fit, but without being uncomfortably tight or restrictive in any way. It is typically made from a “technical fabric” that actively regulates your body’s core temperature. Such fabrics are breathable, offering ventilation, and wicking, meaning that they transport moisture through the fabric and away from your skin.

When we talk about base layers as cyclists, we are talking about a top. You wear your base layer under everything, including your bibs. The only thing you would have underneath a base layer is a bra and/or your heart rate chest strap). Although base layer leggings are available, they’re not really useful in a cycling context because you’d have to wear them inside your chamois, which would chafe.

Because a base layer is managing your sweat, it can be quite (ok, let’s be honest, very!) smelly after use, so try and have enough options that you don’t have to re-use them between washes. It’s the kit item I have most of – I reckon I’ve got 13 in total, because they’re essentially like underwear.

They can be synthetic, woollen (never cotton!) or a mix of the two, with different benefits. When you think of wool, don’t be put off thinking of the kind of thing your nana might knit. It’s an incredibly fine knit produced by a machine – you wouldn’t know it was any different from other technical fabrics to look at.

There are a vast range of styles suitable for very cold weather through to hot conditions. We both really rate Craft base layers, but I don’t much like their website. I find it much easier to judge their products in-store.

Warm weather (20C+)

A summer base layer is typically a very lightweight sleeveless vest made of a synthetic mesh. Its primary function is wicking moisture away – it’s not there to keep you warm.

Andy swears by wearing a base layer whatever the weather, whereas I tend to do away with them at about 25C. If you look at the pro peloton on the road in the summer, you do see some unzipped jerseys with mesh vests underneath. They can definitely be useful in warm conditions. For example, if you do a long climb, your jersey can get really soaked with sweat which feels cold when you descend. A mesh layer protects you from that.

Mild weather (10-20C)

These sorts of conditions are common in Britain and demand a mid-weight base layer. Unless specifically labelled as warm or cool, most base layers will fall into this category.

As a general rule, match the sleeve length to your top: short sleeved base layer under short sleeved jersey; long sleeved base layer under long sleeved jersey. If you wear a short sleeved base layer with a long-sleeved top, you tend to find that your arms feel wet compared to your torso. With a short-sleeved jersey, keep the base layer short sleeved even if you also wear arm warmers. Warmers are skin-tight so it’s difficult to wear a base layer under them. Instead, put the grippers of your arm warmers over the sleeves of your base layer. This will help keep the warmers in place too.

Chilly weather (0-10C)

Once it’s turned chilly, stick to long-sleeved base layers. The only exception is if your skin suit is short-sleeved. In this case keep your arms warm with fleece lined arm warmers but use a short-sleeved base layer. When it’s cold consider crew neck styles for added warmth unless your skinsuits have no collar.

Very cold weather (-10-0C)

When it’s seriously cold, use long-sleeved wool or wool-mix base-layers for extra warmth. It really does make a difference. I found this out when I bought one by accident: I was super impressed by how warm it was at -5C, checked the label and saw it was 50% wool. You should definitely go for crew necks at these temperatures too – every bit of heat saved counts.

If you want a full guide to what to wear and when, check out this post.

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