# How important is a hot weather base layer?



## thebikingcello (Feb 3, 2011)

I mean, we spend this money on jerseys that are made of a special fabric that is ment to keep you cool and wick sweat. I can think of a base layer keeping your jersey drier from sweat making it more breathable, is that why?

thanks!


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## Kai Winters (Aug 23, 2009)

I do not like wearing any sort of base layer during the warm weather months...not many up here.
They are a god send for the rest of the riding seasons.


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## pdh777 (Oct 7, 2005)

Never wear a base layer in warm weather - too hot.

Wear them at other times of the year.


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## aries14 (Sep 4, 2009)

I wear a base layer during the entire riding season.


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## LC (Jan 28, 2004)

Base layer in the summer is not going to help keep you cool, but some wear it to save skin in the event of a crash while racing. The idea is for the two layers to slide against each other.


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## heathb (Nov 1, 2008)

No base layer for me in the summer. You want to get rid of body heat as fast as possible. 

For winter I've got tons of different base layers as the temp creeps down.


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## bdaghisallo1 (Sep 25, 2007)

I think a lot of the supposed performance benefit of base layers in the heat vanishes if you ride in high humidity. I live in Bermuda and the rel humidity rarely drops below 80% in the summer. Even now with the temp around 75F, I am dripping at the end of a ride. There is no way that a base layer would do anything other than heat me up. It's all about getting airflow over the skin, so for me it's sleeveless jerseys with no base during the height of the summer. 

In places with low humidity, I could see the structure of a base layer getting the chance to do what it was designed for since your sweat would evaporate so much quicker. But here, the base layer so quickly gets saturated with sweat that it just becomes a sponge.


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## RUFUSPHOTO (Oct 14, 2010)

I ride with an under armour compression base layer top all the time. It definitely keeps me cool and it is comfortable.


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## brucew (Jun 3, 2006)

I can't imagine why I'd want more insulation in the heat.


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## ZoSoSwiM (Mar 7, 2008)

I wear a base layer in heat up till the 80's or so. Then it really depends on the humidity. If it's dry heat I'll still wear a base.

I find that thin skin tight base layers really help cool me off.. Plus I wear full length sleeves for added sun protection.. I'll take a little more heat and save my skin any day.


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## MShaw (Jun 7, 2003)

aries14 said:


> I wear a base layer during the entire riding season.


I'll wear one till it gets into the mid-90s with that much humidity.

Until then, I'm wearing something under my bibs.

M


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## Paradox_Q (Aug 1, 2009)

I don't wear a base layer in the warmer months. Even with the low humidity here in Colorado Springs it would be too warm for me. Sleeveless jerseys work best for me.


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## jrz1 (Mar 15, 2006)

I live in South Carolina where we get heat and humidity (high today will be in mid 90's). I got a very sweet deal on a Giordana summer sleeveless base layer so I picked one up and for the first time I have used one in the heat. I was VERY skeptical at first. It seems so counter intuitive that ANOTHER layer in the heat could actually cool you. Than I talked to an army buddy of mine who served in Iraq (120 degreees in summer). He said they all wear summer base layers there. Army issue. He was adamant that it helped in the heat. So I gave it a try. My original plan was to use it only this spring and then relegate it to the drawer once temps approached the upper 80's. Well, first of all I found it very comfortable. It is ultra light, and fits tight and is soft on the skin (this really sounds like I'm getting in touch with my feminine side, lol!). At any-rate, because of this I have just kept it on. Rode the other day with it when it was in the low 90's and felt great. I think even in the humidity it helps wick sweat and more importantly for me it keeps my sleeveless jersey from clinging to me. So far I will say that I am a believer.


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## GetReal (Jul 26, 2010)

I'll wear a base layer for long climbs in the mountains (temps in 80's). Not much warmer but it sure keeps the annoying killer horseflies and bugs away for most of the ride.


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## nOOky (Mar 20, 2009)

I would say I don't wear a base layer because a cyclist is generally moving and has the advantage of convection to help remove heat from the skin. If you were standing or walking then the additional layer might keep the water next to your skin which helps cool you much like the body's own natural process. However not having that layer against your skin with air flow over it allows the sweat to be taken away that much faster thereby cooling you more efficiently.
(I think?)


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## Kerry Irons (Feb 25, 2002)

*Cooling*



nOOky said:


> I would say I don't wear a base layer because a cyclist is generally moving and has the advantage of convection to help remove heat from the skin. If you were standing or walking then the additional layer might keep the water next to your skin which helps cool you much like the body's own natural process. However not having that layer against your skin with air flow over it allows the sweat to be taken away that much faster thereby cooling you more efficiently. (I think?)


Actually, it is evaporation that provides nearly all of the cooling for a bicyclist at speed. Convection losses would be very small, especially as ambient temperature approaches body temperature. Evaporation of sweat is a far more important source of cooling. I'm agnostic on base layers and I don't use them, but convection cooling is not the issue.


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## nOOky (Mar 20, 2009)

You are right I used the wrong term!


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## looigi (Nov 24, 2010)

You only need one layer. If a "base layer" is doing something your jersey isn't, then fix your jerseys.


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## rubbersoul (Mar 1, 2010)

marketing genius!


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## F45 (Nov 25, 2010)

Riding up hills in the summer around here is an exercise in pouring water on onesself so riding speed isn't limited by overheating. Adding a base layer is just ludicrous.


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## DrSmile (Jul 22, 2006)

Your skin is the most effective cooling "base layer" possible. Everything else is just sleight of hand and inaccurate advertising. No amount of "wicking" can evaporate sweat more effectively than exposed skin to provide a cooling action.

It is possible to wick away moisture faster, but this gets rid of the cooling effect from evaporation, defeating the purpose of the wicking action in the first place. This is in fact the idea behind base layers for COLD conditions.


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## ZoSoSwiM (Mar 7, 2008)

DrSmile said:


> Your skin is the most effective cooling "base layer" possible. Everything else is just sleight of hand and inaccurate advertising. No amount of "wicking" can evaporate sweat more effectively than exposed skin to provide a cooling action.


I sort of disagree.. 

When riding my trainer all winter long I wear the same skin tight full sleeve base layer but no additional layers. I've found that when wearing the skin tight shirt in front of a fan I cool off BETTER than I do without a shirt on. If I ride shirtless I still feel hot. With that layer on it gets soaked after a few minutes and the fan chills that so I feel cooler. I've also watched my heart rate increase a few beats when wearing no shirt at the same effort.. 

So I don't believe wicking base layers are hype at all..


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## Kerry Irons (Feb 25, 2002)

*Partially true*



DrSmile said:


> Your skin is the most effective cooling "base layer" possible. Everything else is just sleight of hand and inaccurate advertising. No amount of "wicking" can evaporate sweat more effectively than exposed skin to provide a cooling action.
> 
> It is possible to wick away moisture faster, but this gets rid of the cooling effect from evaporation, defeating the purpose of the wicking action in the first place. This is in fact the idea behind base layers for COLD conditions.


Wicking fabric takes the sweat to the surface of the fabric for evaporation and when it evaporates, you feel the cooling effect. Does a fabric provide a slight insulating effect? Yes, but you certainly can feel the cooling and if the sweat is dispersed across the fabric you will get more cooling effect than if you let the sweat drip off your bare skin (no cooling effect). A base layer does result in a slight additional insulation effect, so it is hard to see how it would be cooler than a quality jersey made of a wicking fabric.

I think the main potential benefit of a base layer is to reduce road rash because the jersey and the base layer slide agains each other rather than the jersey sliding against your bare skin.


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## seeborough (Feb 3, 2004)

Kerry Irons said:


> Wicking fabric takes the sweat to the surface of the fabric for evaporation and when it evaporates, you feel the cooling effect.


 From personal experience, i.e. many years of riding in 90+degrees from late May to at least mid-September, I agree to the above. I wear sleeveless DeFeet undershirts for every ride and have never felt them to be hotter than riding with a jersey only.
One aspect which has not received much attention is the fact that a summer-weight underlayer used in very high humidity (eastern NC) prevents the discomfort of having your completely soaked jersey slap against your skin. The effect is magnified after leaving an air conditioned gas station after a rest stop. Lastly, the crash protection, probably aided by wearing bibs, has been helpful in the odd sprint pile-up.


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## malanb (Oct 26, 2009)

eeeh. no way I would use a base layer on hot days. It gets upto 43C where I live.


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## looigi (Nov 24, 2010)

seeborough said:


> ...prevents the discomfort of having your completely soaked jersey slap against your skin.


Your jersey it too big or poor fitting. It should fit as well as your base-layer and basically supplant it...unless you're wearing baggy t-shirt like jerseys as many mtbers wear.

Lou


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## Len J (Jan 28, 2004)

I wear loose mesh base layer......only to prevent nipple chafing from the bib straps. Still allows the wicking properties of the jersey to work and keeps me cool enough.

YMMV

Len


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## Golfguy (Nov 20, 2010)

I certainly wouldn't wear a base layer here in Texas in the summer. I'd roast. Too hot, too humid.


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## gus68 (Oct 19, 2010)

I took a test for selling craft stuff. I'm not advocating their position but simply stating it.

Summer base layers are made with very light wicking material (see through really), made to be tight and stretchy. They only increase water evaporation on your skin. The steady evaporation is a better way to control your body temperature. On hot humid days you feel hotter because the water on your skin isnt evaporating, evaporation produces the cooling effect, They had a cool tag line, where athlete meets atmosphere. Anyway, I prefer defeet stuff anyway, Could be a bunch a marketing garbly ****, who knows. 

my two cents


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## seeborough (Feb 3, 2004)

looigi said:


> ...Your jersey it too big or poor fitting....


Interwebs-clairvoyance?


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## MShaw (Jun 7, 2003)

One of the other benefits that isn't being said is the waffles in the summer base layers is also making micro-climates keeping you insulated from the worst of the heat while still allowing evaporation and cooling.

I've been going without base layers the last few days as an experiment. Its too soon to say, but so far, with the base is as effective as without.

M


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## majura (Apr 21, 2007)

I always wear a base layer on bar the hottest most humid days (above 35˚C or 95˚F). Even then I may still wear one.

My summer baselayer is Craft's Cool Mesh Superlight. IME it helps regulate my body temp better than without one- all except when it's very humid out. Even yesterday's post-work ride the afternoon was a sunny 24˚C/75˚F but some spring thunderstorms covered up the sky and a little rain fell causing the temp to drop a little, happy to have a base layer on to keep me comfortably warm.

Another reason why I wear one which I proved (again) a few weeks ago is that if you come off the bike, it helps protect your back/chest from road rash.


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## jrz1 (Mar 15, 2006)

I would venture to say that the majority of those voicing a very negative opinion of summer base layers have not actually tried one. I know before this year I would have felt the very same way. That being very sceptical of them. But now that I have been riding with one, several times already on days in the 90's, I am a believer. Remember it must be a SUMMER, usually sleeveless, base layer from a reputable company. I find them cool, comfortable, and clinging jersey preventing. Try it before you bash it. You may be surprised.


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## MShaw (Jun 7, 2003)

jrz1 said:


> I would venture to say that the majority of those voicing a very negative opinion of summer base layers have not actually tried one. I know before this year I would have felt the very same way. That being very sceptical of them. But now that I have been riding with one, several times already on days in the 90's, I am a believer. Remember it must be a SUMMER, usually sleeveless, base layer from a reputable company. I find them cool, comfortable, and clinging jersey preventing. Try it before you bash it. You may be surprised.


Humph. That's like tryin to get a ******* to eat sushi. 'I ain't eatin no *bait!*'

I wore my Garneau mesh base today. Started out in the mid-80s but thick enough to cut with a knife, them migrated to the upper 80s and still thick enough to cut with a knife. :thumb

M


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## Wood Devil (Apr 30, 2011)

It gets so hot and humid up here in New England during the summer, my theory is less is better. 

Now, if the police would stop bothering me, I'd find myself riding in the buff far more frequently. :ihih:


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## Jay Strongbow (May 8, 2010)

Why do people who say they cool you down wear a sleeveless one?

If I thought a summer base layer kept me cool I'd keep my arms cool too (and get the extra bonus of sun protection). If you feel the keep you cool wouldn't a long sleeve turtle neck be best? Heck, I'd get tights too and keep my whole body cool.


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## George M (Sep 25, 2008)

I started wearing a base layer, when I noticed all the Mexican landscapers wearing long sleeve shirts, with short sleeve shirts under them. It's pretty hot and humid in south Texas, but I really don't notice that much difference if I wear a base or not.


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## dysfunction (Apr 2, 2010)

Golfguy said:


> I certainly wouldn't wear a base layer here in Texas in the summer. I'd roast. Too hot, too humid.


I wear one in Southern Arizona in the summer and it sure ain't cool here.. it's like wearing a swamp cooler. Even during the monsoon, when it can be humid.


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## vagabondcyclist (Apr 2, 2011)

I tend to wear one. Started road riding in south Florida where it gets hot and humid in the summer. I kept using one in Ohio in the summer as well. With bibs, I think a base layer helps move sweat to my jersey, plus the base layer adds a bit of compression.


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## qatarbhoy (Aug 17, 2009)

Here in the Arabian desert (temps already over 100F and humidity can be off the scale) I always wear a T-shirt under my shirt when riding to work, but when road riding I just go with bibs and a S/S jersey, preferably with a full zip. If compression/base layers weren't so ridiculously expensive I would give it a a go though, as I can see the benefit of wicking sweat away evenly to promote better evaporation.


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## looigi (Nov 24, 2010)

I find a tight fitting jersey to be cooler than a loose one. Wet fabric that is not in direct contact with the skin doesn't cool the skin as effectively. 

You don't want to move the water away from the skin, you want it to evaporate while in thermal contact with the skin. That's the opposite of what you want in cold weather, where you use base layers to wick moisture away from the skin so that when it does evaporate it doesn't cool you down so much.


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