I definitely saw a few, but not many, riders wearing them in Stage 8. One of the guys in the "contenders group" on the Morizine-Avoriaz, but I couldn't figure out who...

I'm sorry, do any of you actually ever ride your bike?

srsly

My wife loves them. They do seem to help with cooling but in general I just prefer to not have my limbs constricted.

:raises hand:

Baselayer cooling you down?

Can't see how that would work.

And put another way, there are people who live and cycle in 100-120F daily who probably have a little more practical experience on how to dress for heat than even TdF riders.

Brian's post is on the money re heat transfer theory. However, in terms of application, it seems to me that there are a couple of gaps between theory and practice.

1/ The issues with high humidity have obviously been pointed out - but it extremely hot/dry heat, the sweat often doesnt stay on your body long enough. In such case, does a wicking base layer provide a benefit? There is probably a sweet spot of ranges when it works, it seems.

2/ If you are wearing a tight-fitting base layer to wick heat, do you always benefit from an outer layer? A loose-fitting outer layer does reduce the heat transfer to the body, but cyclists dont exactly wear dish-dashas, so that gets a bit academic.

I dont know the answer to this, but I am pretty sure that I'll trust practical experience to people extrapolating basic theory into a more complex situation.

I do wear a base layer when I go hiking in the mountains, with the temperatures in the 90s. It is effective, especially when the sun is hot but the air is relatively cool and the amount of sweating is moderate. I sure as hell do NOT wear a base layer when cycling when the temperature exceeds 100-110F and the air itself seems to scorch your lungs.

Works for me.

V.

Couple of things people have gotten wrong..

A lot of pro bibs are cut very low and wide so that they are cooler in the summer. I think castelli does this with a lot of their bibs. Often when someone is hunched over (like on a bike) with their jersey unzipped you can't see the bib straps because they are cut so low/wide. Andy seems to be liking his bibs. So is Lance (you can see the white bib strap behind his right arm)

Base layers should be very tight against the skin, tighter than most jerseys. If you just wore a base layer (go ahead) you'd be fine, but most people like the look of wearing a jersey. I think i'd look pretty stupid in just a base layer, like someone riding in a pride parade or something. Wearing a base layer under my jersey gives me the best of both worlds. A very thin layer that cools me down, and a second layer that keeps the sun off of me, makes me not look stupid (at least less stupid than just wearing a base layer), and keeps me cooler than any other decorative alternative outer layer (i.e. a t-shirt or something).

My bibs are a pretty effective base layer I feel, but only up to my hips. On the bike, there's often a gap between my bibs and my stomach, since my bibs aren't skin tight there they suck at keeping me cool. The same is true with base layers that aren't skin tight. Some people have suggested making jersey's out of base layers, if they weren't skin tight, they'd be just as effective as any other jersey more or less. And if they did make them skin tight, they'd be called base layers.

The reason that the overlapping area between the top of my bibs and the bottom of my jersey gets sweaty/hot is because my bibs are no longer skin tight. They are tight on my sides under my jersey, and sure enough i don't get sweaty there. To combat this phenomenon many bibs manufactures (i've had some casteli's like this) make very low cut bibs, i don't like the feel of them though. I'd rather have the overlap and not worry about accidently exposing myself while riding. A lot of pros disagree with me and would rather have a low cut bib to keep them cooler, but I guess they didn't realize people on BF wouldn't realize that their bib straps were still there and have just gotten pushed off to the side where an unzipped jersey still covers them.

On the topic of base layers in humidity, it's pretty dry most of the time here in Utah so I don't know. But I know in past tours some days they were them, some days they don't. It's been pretty accepted here in the past that base layers don't work in humidity too well.

So there you have it: base layers wick away sweat and jerseys wick away stupid.

Seems like a perfect (and necessary) combination for most BFers.

Between wearing underwear that serves as a baselayer (thereby preventing their junk from overheating and being rendered impotent) and sporting hairy legs that promote evaporative cooling, this thread demonstrates that Freds are cooler and less susceptible to overheating than Road Nazis...

Haha, perfect!

Smart Freds, that is. I see so many people around here who must be absolutely toasted riding with their wind jackets when it is 70.

Anyway, went out today on the hottest forecasted day so far, 99 degrees(which is what my Garmin said it was when I rode) and 13% humitidy. I went with my Craft Warm Weather short sleeve black base layer and my regular team jersey. I did a leg shredding all out 5 min interval. Hard to say if I was cooler or more comfortable then without the base layer, but I think I was, and it definitely wasn't worse. I think I will continue to use one on hot days.

Yes but it's pretty clear from reading this thread that the jersey wicking away stupid thing isn't working...or lots of people aren't wearing jerseys

They're probably wearing them inside out

Correct, the Castelli bib I own matches this description.

I called the Tour de France today and told them the riders come on here to read five pages of posts about them not wearing base layers.

The Tour hung up on me.

Brian R nailed it early on in this thread. When the temps are 100+ here, it's dry and an Underarmour Heat Gear compression T under my jersey keeps me cooler than just a jersey alone. In fact a long-sleeve white one keeps the sun from frying my arms. On the other hand, we'll have a heat index of 108 tomorrow, but highs only in the mid-90s. I'll be riding with just a jersey then, as it will be too humid for the compression T to do anything but make me slimier.

In the end, just try it yourself. But I've found it works when it's really hot, and dry.

Well, a lot of posturing back and forth in this thread...

I invite any of you to come to Phoenix this time of year and tell me, truthfully, that adding a base layer makes you cooler. Oh yeah, we're rockin' about 112 ~ 115 degrees Fahrenheit this week. That'll put the temperature above 120 coming off the pavement. There ain't no way I'm wearing extra in this heat.

Personally, I think its just a fad.

But if you say it works for you, then who am I to argue? We can certainly agree to disagree!

totally not talking about you (or pcad, or botto, Machka, etc.) It just seems like a silly debate, and would be solved if people would just go see what works actually on the bike (but then BF would be deserted)

No wonder i'm so cold in the winter, i've been wearing baselayers. Thank God i found this thread, next winter i'll be sure to ditch those things!

Wearing it inside out is great you get twice the use and unless your base layer fabric is a multi layered laminate i doubt it matters!!

Pearl izumi makes a set also, they are marketed more honestly as Sun Sleeves to prevent sunburns.

"totally not talking about you (or pcad, or botto, Machka, etc.) It just seems like a silly debate, and would be solved if people would just go see what works actually on the bike (but then BF would be deserted)"

The problem is, that the best I can tell, this is not supposed to work for me anyway (too humid, too sweaty), so testing it and getting negative results would be pretty meaningless.

"Think some more. Don't you think the mass of water that evaporates depends on surface area? Gedanken: which evaporates faster an insulated column of water 12 inches deep with one square inch exposed to the air or an insulated pool one inch deep with 12 square inches exposed?"

Re-read my post. If sweat is actually dripping off without evaporating, then you may have something, but then you're also probably going to saturate the fabric, contrary to earlier assumptions. And if it's all evaporating either way, no difference. Unless, that is, you assume that you will actually sweat more with the fabric, but that would imply you were hotter, too.

"(Also, you're experience is limited. There are plenty of people who wear light arm warmers for cooling.)"

You could be right. I'll have to watch for this and see.

Edit: Check here: https://www.bicycle-stuff.com/photo20...-H-H/page.html
Looking through a couple of dozen pictures, I'm seeing a bunch of bare arms, bare legs, and bare faces, and zero long sleeves, long pants, or cooling facecovers. I wouldn't say there weren't any there, but there's sure not many if any.

I started wearing them when I went to a trip in the desert in the summer for a wedding. I was skeptical and tried it both ways but it helped. I've been to Tempe/Phoenix in the heat and done races in ~115 degree heat here. I still wear them. It makes me more comfortable. 'Nuff said.

And that's what's important.