Re: Shirt color vs. heat [was Re: the 2003 Cali-MUni week-end thread.]

[system]

johnfoss <johnfoss.tyrbk@timelimit.unicyclist.com> wrote:

>I personally don’t like real dark colors, like blacks, as it gets real
>hot on the trails out here, and shirt color can make a difference. It
>shouldn’t be so hot in October though. Plus, we had a dark NAUCC (and
>Expert) shirt this year.

Actually, real dark colors, especially black, are the best if you want
to stay cool. The dark colors absorb heat better which evaporates the
sweat better and thus cools our bodies better.

Sincerely,

Ken Fuchs <kfuchs@winternet.com>

[muddycycle]

Actually, real dark colors, especially black, are the best if you want to stay cool.

I been wearing white shirts lately they hid the sweat a lot better.

[johnfoss]

I will have to experiment with Ken’s theory some more. I know it’s not Ken’s idea, and it carries a lot of weight because you see lots of desert people wearing black robes & things.

My normal experience is that a black shirt just gets a lot hotter! However, the sweating situation is different from place to place. In Minnesota, there is danger of drowning in one’s own sweat. It flies everywhre, and I squeezed out plenty of “helmet juice” on the group rides at NAUCC. In the drier air of Northern CA, your body’s sweat system works better, because it evaporates very well, dark shirt not required. Plus, the drier the air, the more intense the sun feels. Therefore, the hotter a dark shirt will feel. This may explain Gilby’s tendency toward dark shirt colors…

[harper]

Black in the sun is bad. Black in the shade is excellent. It’s a fantastic absorber AND radiator. White in the sun is good because it’s a reflector. In the shade it’s not so good because it’s such a poor radiator.

[system]

Re: Shirt color vs. heat [was Re: the 2003 Cali-MUni week-end thread.]

On Thu, 18 Sep 2003 14:49:11 -0500, Ken Fuchs <kfuchs@winternet.com>
wrote:

>Actually, real dark colors, especially black, are the best if you want
>to stay cool. The dark colors absorb heat better which evaporates the
>sweat better and thus cools our bodies better.

So because the shirt gets hotter it cools us better?

And if I want to cool down I should stay near a heater so that my
sweat evaporates more?

Klaas Bil - Newsgroup Addict

If the crank is moving then it really sounds as if it’s loose. - onewheeldave trying to pinpoint the cause of a clicking crank

[Chuck_Webb]

Would that be before or after labor day?

[U-Turn]

I think the main thing with the desert nomad clothing that we see in Lawrence of Arabia and on the news reporting events in Saudi Arabia and the like is that it is multiple layers of clothing. The layers are draped to produce huge, flowing air spaces. This configuration eliminates radiant heat absorption from both above (the sun) and below (reflection and re-radiation from the sand)whether the cloth is black or white. A thermocline is created by the delta-T effect between layers. Moreover, evaporative cooling from the skin is still effective because the cloth has enough of a loose weave to permit moisture transfer. So the surface of the skin can still be far lower than ambient, even neglecting radiant heat.

Anyway, this is what I think when I think about this. When I hiked on the southern PCT last time I wore short pants and shirt and a very good Desert Rhat hat; the bare arms and legs are good for hiking but not the best for skin protection. The hat was fantastic and I highly recommend it.

A really good read by a Westerner travelling with the nomads in Saudi Arabia before Lawrence and WWII is Deserta Arabia , by C.M. Doughty. A friend recommended it to me years ago. It was a tough read but a memorable, significant point in my reading life.

[brian.slater]

Originally posted by U-Turn
When I hiked on the southern PCT last time I wore short pants and shirt and a very good Desert Rhat hat; the bare arms and legs are good for hiking but not the best for skin protection. The hat was fantastic and I highly recommend it.

I prefer the Hat-in-a-Bag with the Bird style being similar to the Desert Rhat. The Hat-in-a-Bags are lightweight, collapsible and have very wide brims. Excellent shade with the Big Shade being 18 inches in diameter and a 5 inch wide brim.

[ubersquish]

actually, you don’t want to have better evaporation of sweat. the evaporation of the sweat is what cools you, because it absorbs heat to do so. if you wear colors to encourage the evaporation of sweat, all you’re doing is making yourself sweat more

[U-Turn]

Originally posted by brian.slater
[B]

I prefer the Hat-in-a-Bag with the Bird style being similar to the Desert Rhat. The Hat-in-a-Bags are lightweight, collapsible and have very wide brims. Excellent shade with the Big Shade being 18 inches in diameter and a 5 inch wide brim. [/B]

Looks pretty good. One nice thing about the Rhat that the Bird seems to miss is mesh on the sides; when there is a breeze I get a lot of cooling there. But the wider brim looks like it would be helpful.

[system]

Re: Shirt color vs. heat [was Re: the 2003 Cali-MUni week-end thread.]

>On Thu, 18 Sep 2003 14:49:11 -0500, Ken Fuchs <kfuchs@winternet.com>
>wrote:
>
>>Actually, real dark colors, especially black, are the best if you want
>>to stay cool. The dark colors absorb heat better which evaporates the
>>sweat better and thus cools our bodies better.

klaasbil_remove_the_spamkiller_@xs4all.nl (Klaas Bil) wrote:

>So because the shirt gets hotter it cools us better?

The heat the shirt absorbs is transfered to the evaporating sweat. Plus
some of the body heat of the shirt wearer is also transfered to the
evaporating sweat, thus cooling their body.

>And if I want to cool down I should stay near a heater so that my
>sweat evaporates more?

Yes, if your body loses more heat through evaporation (plus heat loss
through radiation of your body and clothes) than your body gains by
being closer to the heater. There should be an optimal distance from
the heater (probably not close to it) to achieve maximum cooling effect.
(Fortunately, we can’t choose to be the optimal distance from the Sun.)

Why would one have the heater on, if one is sweating? I’d recommend
turning off the heater and turning on the air conditioner (if there is
one) or the fan. Of course a moving unicyclist simulates the action of
a fan by moving through the air.

Note that there are two ways to increase evaporation, more heat and more
wind.

Also, note that cycling shorts are almost always black, so they absorb
enough heat to evaporate the sweat and thus cool the rider.
Unevaporated sweat cools the body a tiny fraction of an equal amount of
evaporated sweat.

Bottom line:

If you regularly soak a light colored t-shirt with sweat on your rides,
you would be cooler if you wore a black t-shirt (or less effectively a
dark color). Note that is more effective on sunny days.

If you occasionally break a sweat wearing a light colored t-shirt with
sweat on your rides, stick with the light colored t-shirt or better yet
ride harder, sweat profusely and wear a dark t-shirt.

Of course, sweat salts will show up better on the darker t-shirts. Wear
your sweat salts proudly!

Sincerely,

Ken Fuchs <kfuchs@winternet.com>

[harper]

Originally posted by ubersquish
actually, you don’t want to have better evaporation of sweat. the evaporation of the sweat is what cools you, because it absorbs heat to do so. if you wear colors to encourage the evaporation of sweat, all you’re doing is making yourself sweat more

This is inconsistent. Is there a misprint in this paragraph? The largest heat transport mechanisms are through material phase changes like freezing, melting, condensation, and evaporation. The body cooling process occurs through the evaporation of perspiration. Heat is quickly removed from the body when the phase of the water is changed from liquid to vapor.

[muddycycle]

Of course, sweat salts will show up better on the darker t-shirts. Wear
your sweat salts proudly!

My Roach leg armor has wonderful sweat salts patterns, must be time to wash them.

[phil]

Re: Re: Shirt color vs. heat [was Re: the 2003 Cali-MUni week-end thread.]

Originally posted by Ken Fuchs
Of course, sweat salts will show up better on the darker t-shirts. Wear your sweat salts proudly!

I have a t-shirt with permanent big blobs where said sweat salts appear to have bleached the t-shirt somewhat. Does that make me hardcore, or just a slob?

Phil

[johnfoss]

Originally posted by ubersquish
if you wear colors to encourage the evaporation of sweat, all you’re doing is making yourself sweat more

I don’t think your body’s sweating speed is affected by how much it already sweated (unless you get dehydrated) or by how fast or whether or not it’s evaporating.

But I know what you’re saying, you don’t need the sweat to evaporate any faster than what’s necessary to keep you feeling cool. Well believe me, in places like Minnesota in the summertime, when the humidity is high, anything to encourage evaporation is a good thing.

[Checkernuts]

If you start with a wet shirt it makes everything alot cooler from the start and you dont need to build up a good sweat before you get the effects of a sweat soaked shirt.

I did this often when I was on Muni rides in northern CA this summer. It deffenatlly works well. Or if you dont care about the sun/ abrasion protection a shirt brings going without one feels nice as well.

Chex.

[ubersquish]

i know that it doesn’t matter how much you’ve already sweated, but wearing a black shirt does nothing but use up sweat. it doesn’t cool you off. and if you can’t sweat fast enough, it’'ll make you hotter

[onefiftyfour]

these are cotton t-shirts, right? i won’t be riding with it on, thus not caring about the sweat efficiency. jeez, sometimes you guys go on and on about stupid stuff … but it’s fun to read