It might seem odd to consider wearing an extra layer in the summer, but the best cycling base layers can make a surprising difference to your comfort.
It’s true that if your aim is simply to be as cool as possible non-stop, then a damp mountain bike jersey without a base will keep you cooler – and that’s probably ideal in short races, or sky-high temperatures. But for the riding that most of us do most of the time, comfort is about more than just minimizing our temperature.
The base layer options we've put to the test in this guide range from under $20 / £20 to over $50 / £50, and they all do a cracking job of making you feel drier. You’ll see that they have a range of fits and technologies and that many of them come in both short-sleeve and sleeveless versions. Our top pick is the Castelli Pro Issue Base Layer, and our choice for the best value is the Brynje Super Micro T-shirt. One more thing to add is that summer base layers by themselves are awesome on turbo trainers, sparing you from rivers inside your jersey or drippy bare-chestedness.
If you're planning some summer MTB adventures, don't forget to protect your eyes too – check out our best mountain bike sunglasses and best mountain bike goggles guides to find the right pair for you.
If you're looking for something for the colder months, head over to our best cycling base layers for winter guide.
The best cycling base layers for summer
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The quick list
Best summer base layer overall
A super light base that looks good, is comfortable with a long, snug fit, and wicks really well.
Best value summer base layer
A brilliant performer that keeps you super dry, and comes at a great price.
Best all-rounder summer base layer
A super-comfortable base that wicks well and has an anti-odor treatment.
Best understated summer base layer
A solid performer made from a quick-drying, hard-wearing synthetic fabric, with a comfortable, snug fit.
Best eco credentials summer base layer
Wicks well and made from recycled polyester with an eco-friendly odor-resistant treatment.
Best summer base layer for luxury
A premium offering, with a light, stretchy fabric, exceptional wicking, and an anti-bacterial treatment.
See the next 6 base layers ↓
Best summer base layer for airflow
With a wide open mesh for maximum breathability and 10 percent elastane for a good close fit.
Best budget buy summer base layer
Ridiculously cheap and very comfortable, the Van Rysel comes with a two-year warranty.
Best super-silky summer base layer
The Translite is very thin and silky, with great ease of movement, so you barely notice you're wearing it.
Best summer base layer for minimalism
Ultra-light front and rear panels offer maximum breathability and contoured side panels give a good fit.
Best multi-weather summer base layer
With a deeply textured, super-soft fabric that transports sweat off the skin, but traps a little warmth when you need it.
Best alternative design summer base layer
A dependable base with a nice fit, breathable fabric, and a great range of patterns to choose from.
1. Best overall
You could think of Castelli's Pro Issue base layer as an almost-mesh shirt for people who don’t like mesh shirts, but that undersells it. The thin fabric does indeed behave like a mesh, with its superlight pattern of almost transparent squares, and that gives it a nice breathable airiness.
But it does this while feeling soft against the skin and very light – at 54g it’s one of the lightest in this guide – and while looking pretty normal too, compared with a mesh. While you wouldn’t exactly wear it outside by itself, I've found it quite a discovery as a shirt to wear by itself on the turbo trainer – much nicer than a normal jersey with a river of sweat running down the middle.
If you’re not the kind of person who’d normally wear a base layer but you’d like something to stop your jersey from feeling clammy, this is a great – if expensive – place to start. Castelli gives it a temperature rating of 15-25C/59-77F.
Like Castelli’s Core Mesh base, I found the fit is snug and nicely long, with easy articulation around the shoulders and no bunched material, and it’s available in short-sleeve and sleeveless versions. It’s 100 percent polyester, but the weave has a nice amount of stretch.
2. Best value
The Super Micro, from the Norwegian brand Brynje, is made from a synthetic mesh. Mesh moves liquid sweat well because of its large surface area, it lets sweat evaporate away from the skin more easily because of the gaps, and it allows you to dump excess heat just by undoing your jersey zip. At that point, the warm air that was trapped in the weave of the mesh gets carried away and the breeze is instantly on your skin.
The Super Micro T-Shirt uses the same 100 percent polypropylene fibers as Brynje’s iconic winter Super Thermo, woven into a thinner fabric with smaller gaps in the mesh. Compared with the more open winter mesh, the finer mesh has more contact with the skin to lift moisture off, and less of a thermal effect because it traps less air.
In terms of the fit and feel, I found the polypropylene feels pretty synthetic but I didn't find it at all uncomfortable, and it’s great value and hard to fault in terms of performance. It stays so dry you can pretty much wear it straight out of the washing machine.
3. Best all-rounder
My guess is most people wouldn’t feel the need to look further for a summer base layer once they’d tried this one. It’s one of the most comfortable I tried in this guide, it wicks really well, and it’s thin but textured enough to hold your jersey off your skin.
Like most of the base layers here, it’s polyester with a bit of elastane for stretch. The material is soft, it uses a filled-mesh weave across the whole garment, and like more expensive options, it’s got flatlock seams and an anti-odor treatment. Probably the thing that seals the deal, for this tester at least, is the nicely cut side panels and well-judged amount of gentle stretch. I found the whole thing stays in place perfectly, but is so light touch that you barely notice it’s on. The gentle stretch would accommodate plenty of body shapes too.
This top also comes in short-sleeve and long-sleeve versions.
4. Best understated summer base layer
Most of the base layers in this guide are made of polyester. Like the Brynje Super Micro, this Gorewear base is made from polypropylene (plus a bit of elastane for stretch), which all else being equal is quicker drying and harder wearing.
The fabric is thin and relatively soft, with rows of tiny holes woven in to help with breathability, reduce weight, and maximize surface area for wicking. Seams are flat locked, which adds to the sense of comfort. I found the length is good, and the stretch is gentle, so it stays snug to the body without a vice-like grip.
While I couldn’t test whether this Gorewear base was harder wearing than its polyester competitors, given most of my synthetic kit seems virtually indestructible, its wicking capabilities seemed very good and its feeling of dryness was impressive. It’s also available in a short-sleeved version. It might seem odd to say that it doesn’t have any wow factor, it’s just quietly capable.
5. Best eco credentials
Isadore is best known for its premium Merino cycling kit, but it also does a nice job of synthetics with eco credentials. The Alternative Short Sleeve Base Layer is very similar in style to the Castelli Pro Issue short-sleeve, and none the worse for it. The weave is much the same ‘virtual mesh’, a chequerboard pattern of lightweight squares and almost filament-thin squares, which maximizes breathability and wicking, without the looks of a full mesh. The cut around the shoulders is similar too, a diagonal raglan seam, which I found gave a lovely smooth fit, great articulation, and a nice look. My sample felt slightly more generous in the sleeve length and less tight in the body than the Castelli, but that may have just been a sizing difference. Even the (very light) weight and the (premium) price are almost the same.
Where it differs is in the yarn. The Pro Issue Short Sleeve is 100 percent polyester; the Alternative short-sleeve has 13 percent elastane for a gentle stretch, and more importantly, the polyester is recycled. The fabric also has an eco-friendly odor-resistant treatment. Downsides are few: you may need to experiment with sizes to make sure you get enough length in the body.
6. Best for luxury
If you want to treat yourself to a premium-priced hot-weather base layer, Rapha’s Pro Team base has always been an easy choice for its combination of style and comfort. This year’s version has a new fabric that is lighter, stretchier, and more breathable. The front and back have the familiar criss-cross closed mesh pattern, and the sides are thinner, silkier, and more elasticated.
A vest would have to try pretty hard to be actively uncomfortable, but I found the Pro Team Base has a Goldilocks amount of stretch: enough to be close fitting and yet not at all restrictive. Its flatlock seams are also particularly good: they’re used on the neck and the arm holes as well as the body, which means that if you’re XC racing in a club jersey, it’s virtually invisible underneath. An anti-bacterial treatment completes the picture.
In use, I found it goes some way to justifying its top-of-the-tree price tag with noticeably good wicking and a dry feel against the skin, even in really sweaty conditions.
7. Best for airflow
Like the Brynje Super Micro, the Castelli Core Mesh base uses a fishnet weave to maximize the movement of sweat and sweat vapor away from the skin. The open weave also does a brilliant job of allowing you to dump excess heat if you have a zipped jersey on top, or just to let the breeze reach your skin if you’re wearing an airy summer jersey.
Compared with the Super Micro, it has a more open weave – more like a thinner version of the winter Brynje. That arguably reduces the wicking slightly, because of a smaller surface area, but I didn’t notice any real difference, and both tops were streets ahead of any solid weave. The Castelli is made with 10 percent elastane, which gives a welcome degree of stretch, and I found the fit around the shoulders particularly nice.
Like the Brynje, the fabric is a bit on the hard side, but I didn’t find it noticeable in use, and I was quite happy for it to feel a bit ‘functional’ in return for the super-dry performance and the way it keeps your jersey off the skin. Like many of the base layers in this guide, it’s available in both short-sleeve and sleeveless versions.
8. Best budget buy
It’s always worth checking Decathlon for kit that punches above its price point. It doesn't always manage it, but often it does, especially if you just want to dip your toe in the water, or you want something that’s functional and does the job, and has been designed by people who understand their sports.
The sleeveless Van Rysel Summer Training Cycling Base Layer hits the spot nicely. It uses a flat polyester fabric that has a similar ‘thick and thin’ pattern to the Castelli Pro Issue base and others in this guide – like a mesh with lightly filled-in holes. It’s heavier than the Castelli version though, and the mesh pattern is not quite so open. I found it has a soft feel, a nice amount of stretch thanks to 17 percent elastane, and a good body length. And, being Decathlon, a two-year warranty.
This particular model only comes in a sleeveless version but there are other short-sleeved cycling base layers in Decathlon's range.
9. Best super-silky
The Translite is an incredibly thin short-sleeved base made from extra fine-gauge polyester. A complex pattern of panels around the back and side body helps to give it a good close fit with great ease of movement and no bunching under the arms. There’s a degree of give in the fabrics, but compared to some others, I found it doesn’t have a tight, stretch feel. Along with the silkiness, the lightness, and the flat seams means you barely notice you’re wearing it.
With a midrange price point and a good quality feel, it could be an easy base layer to recommend for warmer weather. My two misgivings are that when you’re sweating heavily, the sheer fabric gets saturated and feels that way. I also found that the chest fit can be a bit loose when leaning forwards on the bike, but that’s just something you’d need to check when picking a size. It’s also available in a sleeveless version.
10. Best for minimalism
One of the very lightest base layers in this guide, the front and back of the MAAP Team Base are gossamer thin, with a criss-cross weave across them. It’s surely as close as you can get to a mesh without it being a mesh. The sides are a flatter fabric with tiny perforations, and the whole thing fits nicely. I found it fine, though it gets hard to imagine spending quite this much on a vest, even one as breathable and good at wicking as it is. Like the other ultra-light bases, you may find that it simply wets out for a while in the heaviest of sweats.
As well as the usual white and black options, this base comes in navy, violet, or rose (pictured).
11. Best multi-weather
You can always rely on Spatzwear to take an interesting angle on a product, and if you're in the market for a premium-priced summer base layer, the CoolR is well worth a look.
On one level it’s like a bulkier version of the mesh base layers that I enthuse about elsewhere in this guide. The fabric is more deeply textured than those typical flat meshes, which not only makes it super-soft against the skin, it gives a humongous amount of surface area to transport sweat off the skin on one side, and release it from the other side. Look closely and you can see that different ribbed weaves are used on both the mesh area and on the inside of the flat panels too.
I liked it a lot. In pure hot weather, it keeps your jersey well away from your skin, and there’s not a hint of clamminess. It does actually hold on to quite a lot of moisture, which can feel disconcerting when you realize it, but press the top against your skin and it doesn’t actually feel damp or chilled. One of the other nice things about a higher volume top like this is that it helps trap a little warmth when you need it to – on early morning rides, or when you’re in and out of sun.
12. Best alternative design
Like many of the base layers here, there’s nothing super revolutionary about the Ibex Bodyline – there’s only so much you can do with a vest, after all. But it covers all the essentials and has some nice touches.
The fit first of all is lovely, either thanks to the four-way stretch fabric or the shape of the cut in the side body, or both. The fabric is a solid performer. It’s polyester, perhaps a little firmer than some of the others here, and I found it does a good job of keeping the jersey away from the body. The filled-mesh fabric is nice and breathable, dumps heat easily from a zipped top and dries well. The neck and arm holes are reinforced for durability.
In true Stolen Goat style, the Ibex Bodyline base layer comes in a number of designs from classy stripes to lairy patterns and the polka dots you see here.
How to choose the best cycling base layer for summer
How much do I need to spend on a summer base layer for cycling?
Cycling-specific base layers range from rare gems under $/£20 to a sweet spot of quality and value between $/£30 and $/£40, and a cluster of premium models at around $/£50.
As you pay more, you’ll more frequently see more sophisticated wicking yarns or combinations of fabrics, a better cut, or extra features like odor-beating treatments, but you’ll sometimes find these on the better cheaper models too. Sometimes the magic comes from years of quietly refining a design.
What should I look for in a summer base layer for cycling?
The main ingredient of a summer base layer is a good wicking fabric – one that moves sweat from the body. That’s usually polyester, sometimes polypropylene, and never cotton, which just holds on to sweat. Merino wool is also too warm and damp for a summer base layer.
A fairly close fit with a little bit of stretch enables moisture wicking to work properly and means the base sits unobtrusively under your jersey. You also want a generously long cut so it stays tucked in as you lean forward on the bike. A good cut around the shoulders and armpits avoids bunching or pinching, and flat-locked seams can add comfort.
A mesh fabric – either a fully open mesh or a partially filled mesh – is ideal for breathability, moisture movement, and, if you have a zip jersey, for dumping excess heat.
What’s the difference between a summer and winter base layer?
They’re similar in that they move moisture from the body, but a winter base is also designed to trap warm air in its fabric. The truth is that many base layers will do very nicely for at least three seasons; you just might want something specific for the hottest summer months or the coldest winter ones. A summer base layer can also add a bit of extra warmth under a winter base too, in the most frigid conditions.
Do cycling base layers keep you cool?
A jersey with a base layer won’t keep you cooler than a jersey with no base layer. This is partly because the base layer will add some insulation. And partly because your body cools itself by putting body heat into evaporating sweat. Because a base layer moves some sweat from the body before it can evaporate, it denies the body the chance to move body heat into the sweat to evaporate it. But… a base layer will very often keep you more comfortable in summer because it keeps a clammy jersey off your skin, makes you feel less sweaty, and essentially gives you a steadier temperature.
How does wicking actually work?
Wicking moves sweat from the body to the outside surface of a fabric, where it can evaporate. It works by an amazing process called capillary action, which causes liquids to flow to fill narrow spaces. In our case, the narrow spaces are the microscopic channels between the specially designed fibers which make up the yarns of our wicking fabrics.
These fibers can be created in different shapes, and different weaves affect the efficiency of the wicking, all of which explain why wicking fabrics don’t all behave in the same way.
How we test cycling base layers
We've pushed these cycling base layers to their limits over several months to see how they perform in a range of temperatures and intensities. The criteria we've assessed them for include breathability, wicking, fit, comfort, style, and value.
Meet the tester
Sean ends up in plenty of sweaty bike situations throughout the year, so it's been great to test these base layers back to back. He's mostly been using them for XC and gravel, with some bivvying, road, turbo and commuting thrown in. He's not particularly fixed about what he uses things for so chances are they'll get taken kayaking and hiking too.
