Do you wear a base layer shirt?

[medinabrad]

I recently talked with a cyclist who says he always wears a light mesh type t-shirt under his cycling jersey. He does this even in very hot weather and insists that it keeps him cooler than a cycling jersey alone. I don't see how this could be cooler than just zipping down the shirt and letting the air cool you.
I would be interested in any opinions on this issue. Brad

 

[boudreaux]

Originally posted by medinabrad
I recently talked with a cyclist who says he always wears a light mesh type t-shirt under his cycling jersey. He does this even in very hot weather and insists that it keeps him cooler than a cycling jersey alone. I don't see how this could be cooler than just zipping down the shirt and letting the air cool you.
I would be interested in any opinions on this issue. Brad

Opinions be dammed. PhD dissertation or nothing!

 

[Squint]

It's something I've wondered about and may only be resolved by trying it yourself.

Some people sweat more than others. The temperature and humidity are also factors as is terrain. You'll get less cooling from air flow while climbing, MTBing, etc.

 

[DesertRider]

High humidity? Mesh base. Low? Less is better.

 

[gw709]

imo wearing one, especially a "technical" type shirt such as a poly prop vest does help keep you cooler HOWEVER the big advantage comes if you happen to fall off and slide along on your back / shoulder /fronet etc when it allows your cycling shirt to rub over a shirt and not your skin.

Often what happens is your cycling shirt "burns" through and if you don't have an undershirt on the chances of road rash on your back etc are increased. Seen this in action a number of times and it seems to work

gavin

 

[bloobuoy]

You may wonder why many pro riders wear an undershirt when it’s a scorching 35C outside. Doesn’t it seem intuitive that a base layer make you feel even warmer?


A good base layer is one of the most underrated pieces of kit. It’s obvious why layering will keep you warm when it’s cold outside, but why would a good undershirt base layer keep you cool when the mercury rises?


A thin base layer will wick the moisture from your body to the outside of the garment which will evaporate as the wind hits it. Evaporative cooling is a wonderful thing.


The other benefit to wearing a base layer in the heat is comfort. An undershirt base layer will wick away the moisture from your skin reduce that wet, clammy feeling which will make you much more comfortable during your ride.

 

[Scotttri]

I think it's all personal preference

 

[toomanybikes]

I wear a Merino wool undershirt, or "base layer" every day of the year.

In winter I will wear a heavier wool shirt, or a long sleeve one but I wear a wool shirt inder my jersey year round.

It keeps me comfy and either warm or cool as the temps require.

It is often 40*C in the summer for me, I still wear it.

 

[jojoma]

I am not a fan of base layers in any type of weather. In warm weather, I just unzip my jersey if I'm hot. In cold weather, I would rather layer up with looser fitting items, such as a vest and a jacket. I sweat a lot, and there is nothing worse than descending in the cold with a wet base layer. A nice jacket with pit zips and various other air flow channels, allows me to regulate the temp when climbing, descending, or just cruising.

 

[alienator]

I wear 'em when it's hot and when it's cold......and I sweat a lot. They help keep me nice and comfy.

 

[CyclingMaven]

Opinions be dammed. PhD dissertation or nothing!

I don't know many experienced Pro' cyclists with a PhD.

Obviously they'll need to hang up the bike and get in the classroom to know something about this topic hey?

Back on topic - From my experience, they do keep you cooler on hot days. Even if this is a placebo effect, it's what's going on in your head that counts.

If you feel cooler, you'll train more effectively and that's all that matters.

 

[vspa]

I think it has to do with tradition also.

As an old dog i wear a base layer shirt year round. Since a couple of years i changed the cotton one for the new "technicals" polyester types.

Here is the thing... One day i didn't have any clean ones to use so i wore my cycling jersey alone. It felt the same really and if you look closely the materials are very similar for both jersey and base layer nowadays.

Just a decade or two ago that was not possible, a cotton base layer was a must because of the materials of jerseys back then.

 

[Adam-from-SLO]

Like others have already mentioned, there are several benifits for wearing a base-layer (comfort, protection of your skin if you ever go down on pavement, etc).

I always at least wear an acrylic tank-top base layer(during hot 90+F degrees , and during colder riding times during winter when its 30-40F degrees). Actually during winter I'll wear the tank top plus usually a short sleave base layer under a long-sleave jearsy to keep me warm + comfy.

What ever it takes to bear the elements easier... get the hours and miles in during the week!

 

[Rockslayer]

Since this summer here in OZ i have been wearing Craft Pro Cool Mesh Superlight Sleeveless Base Layer. It is so light I barely notice it.

I feel more comfortable as it keeps me feeling dry even on the hot days over 30 deg up to high 30's C. As and indicator I notice when sweat is dripping heavily from my face my upper body still feels dry. I am not sure about cooler but it seems much more comfortable than not wearing one.

I wear a warmer layer in the winter keeping me dry and warm.
I think the secret of being being comfortable is staying dry whether it be hot or cold. In winter is it more important to keep dry as sweat will cool quickly causing body to lose heat / energy quickly.

 

[garage sale GT]

Hmmm, I think I'll try it.

Wild guess: it lets the sweat cool you instead of trickling away? Maybe even a cotton blend would be pretty good?

 

[Rockslayer]

Hmmm, I think I'll try it.

Wild guess: it lets the sweat cool you instead of trickling away? Maybe even a cotton blend would be pretty good?

Purpose made synthetics are much better designed to wick the moisture away from the skin then i guess evaporation helps cool the body and also helps you feel drier.

I also like a full zip jersey so i can zip it down as required to vent out moisture as well.

Not sure about cotton blends I avoid cotton as it tends to hold more moisture against skin and doesn't dry as quick.

 

[pat5319]

ALWAYS WITHOUT FAIL!!!!

If you crash you lose less skin and you will have smaller holes in your "jersey", I gaurantee!

I usually use wool in very cold or very hot weather, somtimes synthetic hydrophobic fabrics in cool to very warm to
"save" the wool, and cotton sometimes in moderate to warm weather

When it's near or over 100'F I always wear 2 layers of wool( baselayer and wool jersey) when it's wet with sweat or water it's like having air conditioning HONEST!

 

[alienator]

Guarantee?

 

[Outlook]

Even on the days when it reachs 40 degrees C plus here in Melbourne, it is always better to wear a base layer, as the moisture is drawn from your body, and then evaporated quikcly... this is a cooling effect, and you end up being dryer as well.
;

 

[alienator]

Even on the days when it reachs 40 degrees C plus here in Melbourne, it is always better to wear a base layer, as the moisture is drawn from your body, and then evaporated quikcly... this is a cooling effect, and you end up being dryer as well.
;

That's mostly the idea behind baselayers. Evaporation (and thus cooling) is driven by air flow and surface area of the moisture. Faster air flow and more surface area for a given volume of liquid means evaporation will happen more quickly. With only a single layer of fabric (jersey with no base layer), the fabric can become locally saturated, meaning that in some spots the fabric can hold no more water. In those cases, water can actually close a "pore" in the fabric, essentially decreasing the area of liquid presented to the airflow. What a good base layer does is, in the best case prevent that saturation. Wool does it by actually moving water inside the material itself and expanding. Also where the wool and jersey fabric touch there is a transfer of some moisture to the jersey (through a couple different fluid transfer modalities). What a synthetic garment does is move the moisture away from the body and more directly to the jersey. In both cases, the moisture presents more surface area to the wind for better evaporation.

What about in the cold? The evaporation mechanism is the same. A jersey gets locally saturated. Evaporation is slow, because of the reduced surface area of the moisture, and lot of sweat remains in contact with your skin. Water has a pretty good specific heat, which is the amount of heat per unit mass that is required to raise the temp of that liquid 1°C. Boiled down, that means that water becomes cool and stays cool for a long time, chilling the rider (in extreme cases in mountaineering and some other winter experiences, the chilling is enough to cause hypothermia, severe frostbite leading to loss of limb, and even death.). Splitting that moisture between a base layer and a jersey increases the area of the liquid, increasing evaporation, and lessening the amount of heat the body has to put into the liquid to evaporate it.