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Choosing the right undershirt can make a huge difference to comfort

[This article was last updated on December 13, 2017]

  • Whatever the weather, the right base layer can help keep you comfortable on the bike by providing insulation, wicking sweat away from your skin or both.

  • Lightweight synthetics are good for summer use, while Merino wool has fans all year round because it can be worn repeatedly without getting smelly.

  • For winter use look for features like a high neck, thumb looks and a zip for cooling

  • Minimalism is the watchword in summer, but short sleeves — rather than a sleeveless design — can still help provide a little crash protection 

You can’t build a house without first building solid foundations, and it’s the same when dressing for cycling; it all starts with a decent base layer.

Also known as an undershirt or vest for the jargon-averse, getting the right base layer against your skin can make a big difference to cycling comfort all year round. In winter you wear more layers, and arguably the most important layer is a base layer. How many layers you wear over the top is down to riding conditions, temperature, weather, duration, intensity and personal preference. Start with a good base layer and you’re off to a good start to cycling happily through the winter.

A base layer isn't quite as important in the summer, but can still make a useful contribution to your on-bike comfort. A lightweight base layer will help move sweat away from your skin, a job some jerseys don't do quite as well as you might hope. And there's another reason why you'll often see pros wering base layers even in the height of summer: if you crash, your jersey will slide over your base layer, reducing damage from abrasion.

Choosing the right base layer

The job of a base layer is quite simply to keep you dry when you’re sweating, by pulling moisture away from your skin. A base layer also provides a layer of insulation, and you can tailor how much insulation by the base layer you choose. As the base layer sits next to the skin, comfort is vital so it’s worth investing in a high quality base layer. You don’t want any irritation when you're cycling.

Base layers came in many varieties: different sleeve lengths, different fabrics and weights, high collars and low collars; no two base layers are the same. A base layer doesn’t have an easy job, and the trick is to find one that suits your demands and style of riding.

Lightweight base layers are ideal for year-round cycling and suit hard charging cyclists who produce a lot of sweat. They are good at keeping you comfortable on fast-paced rides or warmer days, or when climbing lots of hills.

Heavier weight base layers are good for really cold days and providing essential warmth, or when you’re riding at a lower intensity - maybe touring or cycling to work. 

Long or short sleeve, or sleeveless?

You can choose base layers with short or long sleeves, or sleeveless. Sleeveless and short sleeves are best suited for warmer days and the summer, but depending on the layers you’re putting over the top, and how cold it actually is, a short sleeve base layer can still be useful in the winter. Sometimes it’s simply not cold enough for a long sleeve base layer, and you can always add arm warmers if going with short sleeves.

Long sleeves are the business for the coldest days though, and paired with a soft shell jacket offers perhaps the most versatile and suitable outfit for typical UK winter weather. A long sleeve thermal base layer and good soft shell jacket is a really good setup, for example.

Material choice

Base layers come in a variety of materials, falling into two camps; man-made and natural materials.

Merino wool is the most common natural fabric base layer. Merino is great because it copes with a wide range of temperatures and doesn't pong when you get sweaty, and it’s very soft next to the skin. It comes in different weights to suit different temperatures, from lightweight to thermal insulation.

Not all merino base layers are the same, there are different weights of merino, and some use 100% merino wool for the construction while some combine merino with another material like polyamide or polyester to provide extra stretch for a better shape and more durability, so you get the best of both worlds, with the faster drying time of the man-made fabric. Such material blends are also easier to care for than 100% merino wool base layers.

If you are cycling every day, or you’re riding twice a day because you’re commuting to the office, then a merino base layer has the advantage that you can wear it for several rides before it needs a wash. Just hang it out to dry and it'll be good to go again.

Man-made synthetic base layers like polypropylene and polyester are generally better at wicking sweat and are usually much lighter, and many people prefer how they feel next to the skin. Such materials can get smelly when you sweat though, so you certainly can't wear them for multiple rides, but recent material developments have seen this become less of an issue than it used to be.

Man-made materials are typically better at actually wicking sweat away from the skin. Whereas merino holds onto the moisture (but retains heat so doesn’t get cold), man-made materials provide excellent wicking properties and don’t hold onto much water. They dry quickly, so are ideal for high intensity cycling. Man-made material base layers are also less bulky and typically provide a closer fit on the body than merino base layers.

Aside from material choice, base layers are available in a wide range of thicknesses, from lightweight summer tops to chunky Arctic-ready base layers. You need to take into account the average temperature that you aim to ride in, the duration and intensity of your cycling, and what layers you plan to wear over the top, to help you decide what base layer is right for you.

Some people also run hotter, and so can get away with a lighter weight base layer, and some people need the extra insulation of a thicker grade base layer. So try and choose the base layer that best fits your requirements. What works for one person won’t necessarily work for you, everyone is different, and experience is the only way to find what works for you.

Some base layers are offered with a wind stopping material used in the chest panels. Why? With wind protection next to the skin, it frees you up from having to wear a windproof outer layer and gives you a little more versatility. For example, you could combine a windproof base layer with a long sleeve jersey that doesn’t have any wind resistance, with the base layer keeping the wind out, providing a good option for high intensity riding. However while they might sound perfect they don’t handle the buildup of heat as well as regular base layers so it’s possible to overheat in them

The weather in the UK can vary hugely, even from one day to the next, so having a couple of different base layers so you can dress appropriately is a good way forward.

Fit and shape

For a base layer to do its job most effectively, the material should sit flush with the skin. If you’re riding at a lower intensity or commuting, then a looser baggy fitting base layer may be fine, but for higher tempo cycling when you expect to produce a large amount of sweat, look for a close fitting base layer.

The more stretch a fabric is generally the better the fit. Also look for smartly placed seams to avoid discomfort, the base layer will dictate the comfort of your whole outfit so check the insides carefully.

Comfort is critical and it’s not just the material being soft next to the skin that is important, t’s also worth looking for a base layer flat seams and no labels or tags, anything that can cause irritation or discomfort.

Most base layers have low neck lines but some heavier duty base layers can have taller necks to provide more insulation on cold days. Some base layers have a zipped neck which can be useful to ventilation on longer climbs or if you find yourself overdressed.

Also check the length of the arms on a long sleeve base layer, you don’t want them coming up short on your wrist, but you also don’t want any material bunching up in the sleeves of your jersey or jacket.

Another thing to consider is length. Some base layers have more length so you can get a good overlap with your bib tights, providing a bit of extra insulation around your lower midriff. Some base layers are a bit lower at the back also to make sure there’s no chance of exposed skin when crouched over the handlebars.

Caring for your base layer

Most base layers these days can be chucked in the washing machine on a regular wash with your other cycling clothes. However, it is important to check the washing and care instructions with any base layer.  Merino can shrink on a high temperature wash, but many merino base layers are fine at 40°C. With merino they'll usually tell you not to dry clean or tumble dry, and to dry away from direct heat, so no draping over your radiator. 

There’s a trend towards lower temperature washes with modern washing machines but such washes don’t always deal so well with the buildup of bacteria on base layers, which causes the pongy smell. 

15 of the best base layers

As there's so much choice out there, we've picked 15 of the best base layers from the road.cc review archive to provide a good starting point, and demonstrate the variety of choice available. Most of these base layers are available for men and women.

Not enough choice for you? Browse the full archive of base layer reviews

Pearl Izumi Transfer Sleeveless Base Layer — £27.99

Pearl Izumi Transfer short sleeve base layer 2017.jpg

Pearl Izumi Transfer short sleeve base layer 2017.jpg

'Infused with crushed volcanic rock.' That's the blurb for the fabric used on the front panels of the Pearl Izumi Transfer Sleeveless Baselayer. With claimed properties of excellent moisture absorption, great wicking and odour elimination, it covers everything an underlayer needs to provide. And do you know what? It delivers.

The Transfer baselayer feels great in your hands even before you put it on, and you just know it is going to sit softly against the skin with no part itching or scratching as you ride.

Read our review of the Pearl Izumi Transfer Sleeveless Base Layer
Find a Pearl Izumi dealer

Lusso Race Base Mesh Base Layer — £24.99

Lusso Race Base Mesh Base layer.jpg

Lusso Race Base Mesh Base layer.jpg

Like many other tops of its kind, the Lusso Race Base Mesh Base Layer works really well in warm conditions, wicking away sweat and keeping you cool, but it's the overall design and fit that makes the Lusso stand out.

The cut is more like a race jersey than an undergarment, and you certainly feel ready for your ride when you put it on.

As with all of Lusso's kit, the Race Base is made here in the UK and it's good to see that homegrown goods can still compete on price: at £24.99 it's a good tenner cheaper than the recently tested Castelli Pro Issue and even less than the Hackney GT Bang.

Lusso hasn't achieved that price by scrimping on quality either. The overall construction is very neat and tidy – the whole thing just screams a top notch jersey, and it feels impressively durable too.

Read our review of the Lusso Race Base Mesh Base Layer

B'Twin 920 Aerofit Windproof Long Sleeve Base Layer — £29.99

BTwin Aerofit Windproof Long Sleeve Cycling Baselayer.jpg

BTwin Aerofit Windproof Long Sleeve Cycling Baselayer.jpg

Want a technical winter baselayer that will allow you to keep the other layers off? BTwin's Aerofit Windproof Long Sleeve Cycling Baselayer could be the answer.

Baselayers – generally speaking – tend to be thin layers of fabric that help provide a passage for sweat to move from skin to the outside, and as a result perform a key function in keeping the body warm when needed, and cool when not.

BTwin's Aerofit is a technically constructed top with a race cut that's designed to do the former and help you resist the cold thanks primarily to its slightly thicker construction and front windproof panel. Putting it on is like donning body armour – genuinely making the cold outside seem a little less hostile compared with thin merino-blended baselayers and giving you the confidence to shed a layer when heading out.

Read our review of the B'Twin 920 Aerofit Base Layer

Ekoi Morpho Senza Unisize — £26.44

EKOI MORPHO SENZA UNISIZE 2016.jpg

EKOI MORPHO SENZA UNISIZE 2016.jpg

The Ekoi Morpho Senza Unisize is an excellent baselayer, shifting sweat really well to keep you dry and comfortable.

This top is made from Dryarn – 80% polypropylene and 20% polyester. Perhaps I've been doing this job for too long, but I know from experience that polypropylene makes excellent baselayers because it's very lightweight and doesn't absorb sweat. That's exactly the performance you get here, the fabric moving moisture away from your body quickly and effectively without getting waterlogged itself.

Read our review of the Ekoi Morpho Senza Unisize

Lusso Dryline Base Layer — £32.50

Lusso Dryline Base Layer.jpg

Lusso Dryline Base Layer.jpg

The Lusso Dryline Baselayer promises to be lighter and more insulating than merino. Performance is indeed very good and it fits like a glove.

When something only weighs 78g, arguing the toss about lightness is only relevant to the most weenie of weight watchers. That said, the Dryline Baselayer is indeed very light. It's made from Dryarn, an Italian fabric that's claimed to be lighter, more breathable and more insulating than pretty much anything else. I'm a huge fan of merino baselayers – mesh and normal – for warmth, cooling and moisture control, so approached the claims of the Lusso base with a sceptical eye. The bottom line is that the Dryarn fabric is indeed very good at keeping you warm, cool or dry, or a combination of the three.

Read our review of the Lusso Dryline

​Craft Active Extreme 2.0 CN LS — £20-£40

Craft Active Extreme 2.0 CN LS.jpg

Craft Active Extreme 2.0 CN LS.jpg

Tester George Hill says: "The Craft Active Extreme 2.0 CN LS is an excellent baselayer that manages heat better than almost any I have used. Having worn this in freezing and mid-range conditions, I can testify that not only does it keep you warm, it also has great wicking and breathability.

"Craft describes it as a baselayer for 'medium-cold to cold conditions'. This is fairly ambiguous and open to a wide range of interpretations, especially as Craft is a Swedish company, so its medium-cold is probably our hypothermia-inducing. I used it in temperatures varying from -3 to 10 for the duration of the review."

Read our review of the Craft Active Extreme 2.0 CN LS
Find a Craft dealer

Castelli Pro Issue Short Sleeve Base Layer — £35

Castelli Pro Issue SS Base Layer.jpg

Castelli Pro Issue SS Base Layer.jpg

The Castelli Pro Issue SS Base Layer is a superlight, super-comfortable baselayer that performs brilliantly and has topped my list of go-to layering, writes tester Sean Lacey.​

Made from 100% polyester 3D mesh fabric, first impressions are that it doesn't seem to weigh anything, and if you are a bit prudish it is almost see-though. Lingerie it is not, though, and its credentials include a wider neck for a better fit under a tight collared or aero jersey, reduced seaming on the shoulders for comfort, and a flat hem so it doesn't create a point of irritation on the waist.

Read our review of the Castelli Pro Issue short sleeve Base Layer
Find a Castelli dealer

Altura Dry Mesh Base Layer — £39.99

Altura Dry Mesh Baselayer.jpg

Altura Dry Mesh Baselayer.jpg

Simple and effective, the Altura Dry Mesh Baselayer should be an essential part of every cycling wardrobe. The benefits of wearing a baselayer are well known among amateur and pro cyclists alike, which is why you'll see racing cyclists on Alpine climbs, jerseys open with a mesh layer on show. The thin open mesh approach to baselayer design allows for increased evaporative cooling when exposed or beneath a layer or two of clothing, cutting down on the time that perspiration sits next to the skin, creating more comfortable riding conditions.

Read our review of the Altura Dry Mesh Baselayer
Fined an Altura dealer

Hackney GT Bang Unisex Performance Base Layer — £38

Hackney GT Bang Unisex Performance Base Layer.jpg

Hackney GT Bang Unisex Performance Base Layer.jpg

Hackney GT's Bang Unisex Performance Base Layer is a functional and versatile piece of kit that has fast become one of our favourite 'essentials'. Its performance in both hot and cold weather is superb, making it a great all-year-round choice and even better value.

The vest is super-lightweight and very soft to the touch. It's made from a fabric called Aviatar, a perforated polyester designed to work in all seasons and weathers, with the side panels made of Lycra to offer a little more give.

Read our review of the Hackney GT Bang

Lusso WindBloc S/S Base Layer — 39.99

Lusso WindBloc S:S Base Layer.jpg

Lusso WindBloc S:S Base Layer.jpg

With the WindBloc S/S Base Layer Lusso has taken the Dryline base layer and added a windproof layer on the front of the torso. It works a treat, offering excellent moisture wicking and a useful amount of protection for fast descents.

A good baselayer wants to sit closely against the skin to maximise its ability to 'wick' – to take sweat from your skin and move it away for evaporation. Various fabrics can do this effectively, including merino wool and some synthetics, and the construction of the fabric can play as significant a role as the raw material itself.

Here Lusso uses Dryarn, made from polypropylene, which it claims is "more breathable than polyester, more insulating than wool and lighter than any other fibre" – bold claims. In use I found it did indeed perform very impressively – the Dryarn is used across the whole baselayer except for the black windproof panel on the front. Even working hard on big Pyrenean climbs I found not a hint of moisture build-up in the usual sweat-trap areas.

Read the full review of the Lusso WindBloc S/S Base Layer 
Find a Lusso dealer

Sportful 2nd Skin Long Sleeve T High Collar — £60

The skin tight Sportful 2nd Skin Long Sleeve T High Collar is comfortable, warm and copes well with sweat. It's a good investment for the winter. It's made from 60% polyproplyene, 27% polyester and 13% nylon. Sportful has used body mapping to add in mesh fabric in key areas, to help with temperature regulation.

Read our review of the Sportful 2nd Skin Long Sleeve T

Craft Zero Extreme Windstopper short sleeve — £34.96

The Craft Zero Extreme Windstopper base layer adds superior wind protection for beating the chill. Craft add a Gore Windstopper membrane to the chest panel of this base layer, which adds impressive protection against the wind. With wind protection next to the skin, it frees you up from having to wear a windproof outer layer and gives you a little more versatility.

Read our review of the Craft Zero Extreme Windstopper base layer

Rapha Women's Long Sleeve Base Layer — £65

The Rapha Women's Long Sleeve Base Layer is a soft, breathable base layer made from merino wool that will prove useful time and time again, both on and off the bike. This lightweight top is made from 100% merino, which might head off some of the haters at the starting line.

Read our review of the Rapha Women's Long Sleeve Base Layer

X-Bionic Energy Accumulator V2.1 — €66.90

X-Bionic Energy Accumulator V2.1 Turtle Neck.jpg

X-Bionic Energy Accumulator V2.1 Turtle Neck.jpg

The X-Bionic Energy Accumulator V2.1 is a fantastic baselayer. And given the price, that's exactly what you should expect. You won't be disappointed, though, this one really delivers. It's among the very best winter baselayers we've tried.

Read our review of the X-Bionic Energy Accumulator
Find an X-Bionic dealer

Rapha Winter Base Layer — £80.00

The Rapha Winter Base Layer is a toasty merino offering with a unique design that'll help to keep you cosy. he 100% merino content and fine, 18.9 micron weave results in a garment with tremendous insulating power for its weight. Flatlock seams eliminate any potential areas of irritation from the design, as does the Raglan sleeve construction. 

Read our review of the Rapha Winter Base Layer

David has worked on the road.cc tech team since July 2012. Previously he was editor of Bikemagic.com and before that staff writer at RCUK. He's a seasoned cyclist of all disciplines, from road to mountain biking, touring to cyclo-cross, he only wishes he had time to ride them all. He's mildly competitive, though he'll never admit it, and is a frequent road racer but is too lazy to do really well. He currently resides in the Cotswolds.

13 comments

Avatar
StraelGuy [1096 posts] 2 months ago
1 like

I've got the Rapha merino long sleeved and, to be honest, I wouldn't cycle another winter without it. Merino is amazing stuff, even when you're really sweating, the sweat seems to form a layer of warm steam around so you feel warm but not wet.

Avatar
Yorkshire wallet [1573 posts] 2 months ago
1 like

Good job the x-bionic is a base layer as it makes it look like you've got a bra on.Terrible pattern placement. Surely someone is taking the piss with that one?

Avatar
drosco [416 posts] 2 months ago
1 like

I like the Aldi ones. Have got half a dozen. I can't remember how much they were, but I suspect they were not much more than a tenner. To be honest, they look suspiciously like the x-bionic ones.

Avatar
OmuGuy [24 posts] 2 months ago
0 likes
"Choosing the right undershirt can make a huge difference to comfort"

True. If you choose water-retaining cotton or a scratchy hair shirt, you won't be very comfortable.

I haven't yet tried merino wool, maybe because I never had any cause for complaint about my  close-fitting Uniqlo Dry and DryEx T-shirts.
I live in Japan and, two or three times every summer, I cycle all day when the heat peaks in the mid thirties. I usually wear a Coolmax or equivalent long-sleeve jersey to protect my arms from the sun and a closefitting Uniqlo T-shirt underneath to suck sweat off my body. I have always felt completely dry except when I stop. Then, my body still feels dry, but the sweat pours from my scalp.
In the summer I've quaffed 11 L of fluid in 7 h. My body never felt at all sweaty.
On summer rides, if I lie down on on a shaded patch of road or other flat surface, I leave a body print in moisture, but I don't feel wet. It's magic. 
Simple wicking polyester seems functionally adequate to me, and I've never detected a difference between Uniqlo dry and Uniqlo DryEx. 
In the winter I often cycle 25 km home after midnight. I don't venture on two wheels when frost is likely, but the air temperature does get close to freezing and I'd had ice in my hair from wind chill. Fleecy bib tights, Uniqlo T-shirt, and Fleecy jersey haven't failed me yet. I'm warm enough and never feel wet from sweat. I'd hate to have a puncture and have to stand still for long periods, but the only thing that has ever felt cold after a few minutes of cycling is my extremities.

Again, simple wicking polyester has been functionally adequate.
I think it'skin amazing.

Fashion and style are other matters.

Avatar
Grahamd [752 posts] 2 months ago
0 likes
Yorkshire wallet wrote:

Good job the x-bionic is a base layer as it makes it look like you've got a bra on.Terrible pattern placement. Surely someone is taking the piss with that one?

Whilst the x-bionic styling is unique the comfort of their gear is something to behold, it really surpasses every other a brand of kit I have; just wish it was more affordable.

Avatar
BarryBianchi [419 posts] 2 months ago
1 like

Goosefat.  Next?

Avatar
nortonpdj [193 posts] 2 months ago
2 likes
BarryBianchi wrote:

Goosefat.  Next?

Folded newspaper. Next?

Avatar
alansmurphy [1236 posts] 2 months ago
2 likes
nortonpdj wrote:
BarryBianchi wrote:

Goosefat.  Next?

Folded newspaper. Next?

Tried that but am on an online subscription now, dropped tablet, smashed screen. #badtimes

Avatar
earth [381 posts] 2 months ago
0 likes

Right now I'm after a Helly Hansen LiFA Merino mix base layer.  Despite the claims I find merino still itches.  HH put the synthetic fabric next to the skin and the merino outside.  They work perfectly.

Avatar
LastBoyScout [332 posts] 2 months ago
0 likes
earth wrote:

Right now I'm after a Helly Hansen LiFA Merino mix base layer.  Despite the claims I find merino still itches.  HH put the synthetic fabric next to the skin and the merino outside.  They work perfectly.

I used to feel the same as you about merino - indeed, wool of any kind. As such, I have a collection of things like Nike DriFit and the fantastic Lowe DryFlo kit among various other things.

Up until a couple of years ago, all my jumpers were either fleece or cotton based, until my wife persuaded me to try a couple of merino jumpers, which, I'll concede, are brilliantly comfy (until some bastard moth ate the middle of one of them).

Later this year I am off on a multi-day tour and will need to wear the same stuff for a few days with limited chances to wash it, so, off the experience of the jumpers, I took the plunge and bought a couple of IceBreaker tops (in sales, obviously) and I've been very impressed with them - haven't felt itchy at all, even when working hard on the bike.

Out of interest, I bought 2 of the merino tops in Aldi yesterday - and took them straight back today, because they were immediately itchy and, in the case of the long sleeve one, the fit wasn't right for me, either. The merino socks, however, were great, but they are a mix.

So, give the IceBreaker a go - I've even been wearing a pair of their socks today.

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dottigirl [808 posts] 2 months ago
0 likes

I have load of merino, and my current favourite is Reewoolution. Soft as cotton and enough stretch. It's wearing very well too.

Also have:

Icebreaker (less stretch, socks didn't wear terribly well, one top is a bit scratchy and holey)

Janus (very loose knit and stretchy, one for colder days as I always seem to sweat a lot in it)

Devold (like the fit but doesn't feel like merino, wearing well though)

Ulvang (lovely, lovely socks; gaiter has shrunk and is a bit itchy)

Smartwool (not bought as low merino %, a friend doesn't find it warm and it looks cheap)

Trespass (dreadful - cheap and horrible feeling. I bought the leggings as nightwear and pulled them off straightaway).

 

It's incredible how different each brand/item feels though.

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wycombewheeler [1237 posts] 2 months ago
0 likes
dottigirl wrote:

I have load of merino, and my current favourite is Reewoolution. Soft as cotton and enough stretch. It's wearing very well too.

Also have:

Icebreaker (less stretch, socks didn't wear terribly well, one top is a bit scratchy and holey)

Janus (very loose knit and stretchy, one for colder days as I always seem to sweat a lot in it)

Devold (like the fit but doesn't feel like merino, wearing well though)

Ulvang (lovely, lovely socks; gaiter has shrunk and is a bit itchy)

Smartwool (not bought as low merino %, a friend doesn't find it warm and it looks cheap)

Trespass (dreadful - cheap and horrible feeling. I bought the leggings as nightwear and pulled them off straightaway).

 

It's incredible how different each brand/item feels though.

+1 for rewooloution, I picked some up on sportpursuit one time, wish I had bought more, may favourite baselayers bar fit, fit well, feel great and smell the same after a day sweating as they do when just wet.

Avatar
WashoutWheeler [81 posts] 2 months ago
0 likes

I use the Aldi 100% Merino Wool base layers, I also have an Aldi 100% Merino mid layer if it gets really cold! It was quite interesting  last winter, I rode serveral times with just the base layer and mid layer and on a cold day,I stayed levely and warm but was covered in dew as the merino does its job!

I am not averse to spending good money for good kit,  but I honestly cannot see what some of this other kit offers over Aldis well made, well fitting, natural fibre offerings that often cost less than a quarter of what the highly advertised brands want for synthetics. Other than perhaps brand bragging rights at the cake stop? ;-)!