Reverence: DeFeet Un-D-Shurt and Un-D-Lite
As indispensable and overlooked as the gilet, the undervest is the only piece of cycling kit that comes with me on every single ride, year round, in hot, in cold, in wet, or in dry. While one could be forgiven for assuming an undervest lives out its life as an insulation layer, the undervest serves a critical, more fundamental purpose: as a wicking layer.
If you’ve ever had the misfortune of carrying a gallon jug of water, you will have noticed that water is not particularly light, nor particularly dry. If you’ve suffered the further indignation of having said gallon jug of water poured over your head after making a pithy remark, you will have noticed that the introduction of water to your clothing makes them both heavier and less warm. As cyclists, these characteristics don’t do much for us in the way of making our sport easier from the perspective that sweat is made up largely of water and thus has a tendency to make the clothing we’re wearing both wet and heavy. Enter the base layer, whose specialty is not so much in keeping us warm, but keeping us dry.
If I’ve understood physics correctly, these magical fabrics are designed to maximize the capillary action of fluids by sucking the water in our sweat away from the skin and towards the outside of the fabric where it can either evaporate or at least stop touching us. Even though the fabrics in our jerseys and bibs are heralded as being able to perform this task on their own, they are busy doing other things as well, and I find that using a layer dedicated to this purpose improves the effect greatly.
To be fair, though, the thought of wearing an undervest – or any additional thread of clothing for that matter – is far from inviting when kitting up in the middle of Summer. This is where DeFeet really shines with their multiple weights of undershirts, each targeted at a different temperature range. From the cooler months of September, through Winter and on into Spring, the Un-D-Shurt tank base layer is my go-to garment, keeping me dry but also adding a bit of warmth to stave off the cool air around Puget Sound. Once the mercury starts rising, however, I switch to the Un-D-Lite, which is much more lightweight and purpose-driven towards wicking rather than also insulating.
With both of these pieces, they are so stretchy, soft, comfortable, and good at keeping your skin dry, I never even notice I’m wearing them. I’d like to meet whomever figured out how to make this stuff; their brains must be so big, I bet you can spot it when you look in their ear.
Good tip to remember. Wearing a Craft mesh (hot weather) sleeveless layer feels great. Especially when you want to pull your jersey off in a parking lot after riding.
So do the “cooling” ones actually make you feel cooler?
I totally get the idea behind more wicking = more evaporation = cooler feeling, but the idea of adding more layers in the hot weather makes my brain hurt.
@mcsqueak
If you’re talking about those ICE ones possibly yes maybe. Someone (LG?) makes shoes with an insole with xylitol, which is the sweetener used in sugar-free gum, that supposedly cools your feet. The wonders of science.
Interesting. I spend most of my time riding around 6000′-7500′ here in Colorado, so wicked ranges of temperatures are a normal occurence. This material might be able to do double duty between warnth and wicking. This weekend I put in about 75K at 6200′-10200′ on gravel on my ‘Cross bike and was cold on the one downhill because of sweat and wind. Might be something to use if I can find it here locally. The Copper Triangle is this weekend and the high temp is only about 21C with a kickoff temp of 7C.
Wow, I was just out doing one of the local climbs with the temp hovering just below 100F with my training partner and the Defeet under shirt that is made out of some kind of material that is cool to the touch was a topic of discussion.
@mcsqueak
Look into the great Australian invention – the Coolgardie Safe. Evaporation on the outside = cooler on the inside. Something to do with heat transfer – not sure if this applies to wicking – but it might!
while i completely agree that base layers are incredible in general, i dislike them for warm weather. i have some great merino ones that i adore in anything around 20 degrees or less. between 20-30, i have a tight-fitting, synthetic, super-light layer that does a great job of wicking. above 30, forget about it. i’ve tried and i just can’t do it. day-to-day comparisons in the same jersey both with/without a base layer tell me that when it’s above 30 (and often, approaching 40), and the humidity is at 80+ percent, wearing an extra layer is stupid. both layers are soaked with sweat before too long and then you’re really hating life.
the main thing for me is that when it’s that hot and i have a base layer on, all i end up doing is unzipping my jersey and cruising around with the layer showing. looks better than with no base layer, but in that situation, i prefer to just ditch the layer and leave the jersey zipped (or when climbing, unzip and enjoy being much cooler than with a base layer).
Any time you’re exerting yourself and experiencing any temperature changes, a wicking layer is a good thing. Only you can decide whether you want a(nother) wicking layer under your jersey on a given day. I’m more inclined to choose it if there’s the threat of a chill from a change in weather or airspeed. I wouldn’t start “stacking” for a flat ride on a hot still day.
Non-cycling-related: a light cotton shirt will cool your ass in the desert. Sometimes rapid evaporation right next to your skin is heavenly.
^^ I.e., what he said.
When I was young, dumb and full of …..life I had the opportunity to learn the error of my ways (or rather, the error of my drunken mouth) by having the odd container of fluid or, in one instance, a backhand to enlighten me. I too learnt that said fluid does increase body weight as well as making one colder when stumbling out into the night. It can get a bit sticky when it dries as well.
I also discovered undervests several years ago. I have an old Cima vest that I’ve been using for about 15yrs that still insulates well on cooler mornings. I also have various other brands for use through the seasons, i.e. Autumn to Spring – Canterbury, Castelli, DHB and a Santini. All work flawlessly for their intended purpose. I must admit though that I have never tried using one in the midst of a Sydney summer ride. I’ve always just gone with the jersey. Perhaps it’s worth a try then.
They are great for changeable weather and mid-temperature but I also would not endorse using them in really hot weather.
I know the theory of wicking but experience suggests that after a certain point it is outweighed by having another layer on your body. have various Giordana and Craft vests but don’t wear them when it gets really hot, like above 35C.
Good summer jerseys are also designed to wick moisture away from the body and allow it evaporate it so I don’t see how adding another stage to the process is going to help.
I’ve been riding the UNDshirt and UNDREcycle. The UNDRecycle is incredibly comfortable as well. A great piece. As far as the discussion on whether or not to wear a base layer in high temps I’d add that while temps are a consideration, humidity is a bigger concern. If the relative humidity is high I find base layers to be stifling. My skin wants to breath and the best way to do that when the temp and dew point are both close to each other and high would be to ride naked. Since that’s not legal or Rule compliant I opt out of the base layer. However, when the air is dry and/or cool the base layer is the way to wick. Plus it’s oh so pro.
Any other Colorado cyclists with opinions?? The relative humidity here is typically very low…desert like. These materials sound like a a good idea.
Its funny that I only found out what a base layer was a year after getting my first bike. Don’t think Ill ever need one while I live in Tucson. but its good to know that I might when I move to colder climates.
@RedRanger
Im guessing they would work better in humid areas. its so damn dry here I rarely feel sweat until I walk into the comfort of a ACed building.
I’ve used DeFeet UnDShirts for years, and they are an indispensable item in my opinion. Looking forward to testing the Wool version in the cold here soon… DeFeet really have the accessories game sorted, their socks, warmers and shoe covers get a lot of love from the Welliminati I ride with too.
I’ve always looked at undershirt with some suspicion, doubting it’s benefit. May be it’s time for me to pick one and enjoy a comfortable ride in the sticky weather
@RedRanger
I’ve found that in quite warm (33C) and very humid Singapore that a base layer doesn’t feel nearly as nice as just a light short sleeve over bibs. No matter what you wear, you’re going to be wet after an hour anyway.
@Marko
Agree with that – summer here is when the humidity gets very high, so maybe that’s what makes the base layers less comfortable.
On a ride the other week we were sweating so much we had prune-fingers after the first hour.
@Marcus
Yeah, I tried one of those but found it chafed my back.
@mouse
u clearly weren’t using it with a latex undershirt
De Feet generally freakin’ awesome. Best arm warmers and knee warmers in the universe ever. The UNDshirt is also geat. And their merino gloves are the bomb. Did I mention that their arm warmers (arm skins) are amazing and their knee warmers (kneekers) are similarly the best thing since sliced bread.
@Marcus
It has everything to do with it; wicking bring the moisture to the surface where it can evaporate which then causes the heat transfer. Its actually the reason we sweat (or one of them) in the first place. But we break the system when we put clothes on, which is more important for some people than for others.
@chiasticon
I wind up unzipping the jersey on climbs when its hot, but I still always prefer the base layer – mostly because lycra (which the bibs are made of) has zero wicking ability and just gets soggy; there is no feeling that gives me the heebie jeebies like wet lycra slapping on my torso. Its like taking your helmet off and putting it back on during a hot ride. Yuck.
COOL! And aside from the cooling aspects, I like the comfort they provide by keeping your bib straps off your body. If I don’t wear a base layer on a ride I notice I’m not as comfortable because of the straps digging into my shoulders a bit.
I have a few from Craft, didn’t realize DeFeet made them as well. I’ll put them on my “want” list. I have other stuff from DeFeet and like it all, so I’ll have to give these a shot.
The white one is like a Craft one that I have that I have never been able to find again – a fine, gauzy, mesh-y style as opposed to the little “cells” of some undervests.
@mcsqueak
You don’t even know the Un D Lite is there when you’re wearing it. You not hotter, you’re just dryer. I haven’t tried it – but the UnD Ice is supposed to actually cool you.
Yes! And added benefit is that when you fully unzip on really hot climbing days your pasty bird chest is covered up by the base layer. Big-time bonus!
Yup, Frank. Putting on a wet helmet is very unpleasant. I actually leave mine on even during extended pit stops just because it’s not as bad as putting it back on with the soggy padding. Eck! I’ll just undo the straps and loosen the wheel but leave it on.
Can’t wait to pair up my base layer with my new V-jersey! Going to be so sweet when that package arrives at my door one of these days…
DeFeet UnD Ice is the cooling shirt I was talking about. Sounds interesting in that they don’t want you to wear if the temps are BELOW 80F.
@frank as Velominati Official Thermal Regulation (OTR) partners, will we be seeing some nice V-Cogged base layers, woollen Kneekers, Armskins and the like?
@niksch
These things are indispensable on rides where you’ll be descending, with your torso dry you won’t get chilled nearly as much. While some still do it, you notice that the Pros aren’t grabbing as many newspapers as they used to on the way down (as compared to, say, the late 80’s and early 90’s); its because most of them wear a base layer even when its hot out.
brett – please offer some feedback once you try out the wool ones. I’m looking for a good base layer for cross riding and some road riding. Have LS ones for the really cold days but think these might be overkill for cross riding when you are hitting it hard most of the time.
Wonder if a DeFeet LS would be good, wondering if wool would be too hot. Maybe a Lite/Shurt in LS would be good paired with a LS light jersey.
@ChrisO
The jerseys are good at it, but the bibs aren’t; its less critical with the V-Bibs as Castelli cut them low and the straps are mesh, but the portion of lycra around the lower torso is positively awful at wicking. That zone is my primary motivation for wearing the base layer when its really hot out.
@Marko
Try the Un D Lite, dude.
@brett
Word.
@frank
A good point. I noticed this when I got my first couple of bibs. The cut-rate Descentes were terrible in this way. The Castellis much less bad. This is a good reason to try the extra layer when I otherwise wouldn’t. Thank you.
@ChrisO
You might be on to something – based on the way I understand capillary action works, humidity would impact that effect because it would be more wet everywhere, which would reduce the ability to wick the moisture away from your skin.
Don’t have much experience with cold-weather undershirts, but I found my undershirts to be indispensable in hot weather. I ride with Craft’s and Assos’ sleeveless pieces, but all of them are pretty much the same – they keep the sticky stuff from evaporating on your body, and move it to do so just next to your body. At the end of a soggy, humid, 35c ride (Mediterranean seaside city), the difference between the undershirt-covered torso and the bare arms is unbelievable – the former is nearly fresh-feeling, while the other’s sticky enough to glue with. As a plus, it’s allows me to use the cheaper jerseys on occasion (such as on memorial rides and events) without the associated itching, and protects the nipples from rubbing on imperfect bibstraps.
I’ve been thinking it through for ages, and it seems to me as if a wicking layer makes sense all the time, even when hot and humid, simply because it’s more efficient than our skin by offering a bigger surface area. We feel “stuffy” in it, but it’s mostly psychological – much like the way amateur runners often run shirtless in the summer, despite the fact that the direct sunshine and decreased sweat-wicking makes their situation worse.
@frank
Humidity reduces the effect, sure – but it also slows down evaporation on your skin. I find that the base-layer still does the job better than our human skin (which is also why I wear baselayers at work in the summer). On a dry, 45c desert blast, the effect is amazing – but even when it’s humid, there’s a benefit.
@Ron
I have the craft one, too, its been laying in a heap in the corner ever since I got the DeFeet last fall.
@Nof Landrien
You’re gonna love the stuff we’re (slowly) working towards having them make for us. Socks, wool arm warmers, and kneekers. DeFeet loves them some hardman gear.
@Chris
Yes!
@frank Awesome. Although I do seriously question the need for a long sleeve jersey (V-Kit or otherwise) for all but the absolutely most freezing weather. The combination of woolen arm skins, merino base layer, SS jersey and a gillet or parts thereof is so much more versatile.
@tessar
I’ve found the same situation, though the above observations about humidity give me pause. But in general, I’ve found the same thing you have; even in cases when the jersey is good at wicking, it has too many other jobs to do as compared to a base layer devoted to the function.
That said, a wool base layer in summer is not the way to go; you need a good, lightweight version which does no insulating and focusses purely on evaporation. Even in the baking heat on Maui, the base layer is indispensable.
Good article, Frank. I’ve been wearing my Un-D-Wool for a while and love it. It’s replaced my Descente base layers. Granted, I don’t regularly wear a base layer unless the mercury drops below 50F…
@Chris
I agree; that is the config I wear for the most part all the way down to 0C, after which the LS Jersey comes out…But I prefer a layered approach to a ride over going with thick gear. The -5C to 0C window is very frustrating for this reason because I generally need the LS Jersey in that range, but its overkill with a gilet. That said, I’ll throw the LS Jersey on sooner if the ride is a mellow one.
I also always dress to be cold the first 15 minutes of a ride; if I feel comfortable when leaving the house, I’m overdressed. Once the blood starts flowing, your temperature rises and you’ll be shedding layers which you’ll then carry around the rest of the ride.
@Cyclops
Hmmm, that sounded intriguing but I’m not totally convinced… not enough to shell out 60 quid on a base layer anyway.
Slightly concerned that they don’t appear to have done any actual studies to back up this claim, just relying on what people say. (And also that their website confuses the word effect for affect, but that probably says more about me…)
Apart from that, the claimed effect on the affected areas is achieved when used with an unzipped jersey because it requires wind to cool it, which then has me wondering why it should be a base layer rather than a jersey. Particularly as they claim the material is more abrasion resistant than kevlar.
That means they could make a long-sleeve jersey which was cooler than anything else, won’t tear and will prevent road-rash… but they haven’t.
I’m perfectly willing to test one out for them. They can even stick a thermometer up my arse if they promise to get a professional to write their web copy.
@ChrisO
I hear you there. I’ve been testing out the UnD Ice here on Maui. It’s a pretty constant 55-60% humidity and 20-25C in the shade. I’m not a dedicated user of base layers in hot weather like Frank is. In general, when climbing in the heat, one layer is hot enough, two seems crazy. This is when you really need to be cool, when climbing, when generating all the excess heat. When you are sweating you now have two wet layers of clothing on.
Once riding at speed or descending all that wet clothing does cool the body, but is it better than one light jersey layer? In the low humidity western USA it might work better.
I’m still testing the UnD Ice against my Craft and Santini italian stallion net base layer and will come up with a more definitive review. For now I remain unconvinced any base layer cools during climbing in humid weather.
@ChrisO the contention that there is an affected area necessarily infers that that there is at least some effect which does go some way to the argument as to their efficacy, no?
excellent and TIMELY advice..i am all over this
will buy and try, as its been a record year for heat out here, >100 for over 20 days, the record hottest year in the dust bowl years of 34 was 22 days…so, go figure…and we are just hitting august heat now
its been so hot, i didn’t think i could dress for it, but perhaps i can
thanks
Every one seems to be overlooking the most important aspect of wearing a base layer under one’s jersey: it just looks so f*ing pro!
@frank
@frank
On Frank’s recommendation last winter I got a set of merino armskins and kneekers. They are indeed the business. I was good down to 0C, and only my hands were the real problem below that. DeFeet also makes some pretty nice oversock things. Will have to try their wool gloves, how low temp-wise would those who have used them say they go, and do they layer well?
@CanuckChuck
I’m with you and quite frankly a little shocked I didn’t lead with that. Here’s my original leading photo, but my neck looks just a bit too pasty and my right shoulder too washed out.
@DerHoggz
Because I can’t resist the urge to post this pic of me on the Kapelmuur, you’ll see I’ve got the DeFeet arm skins on as well as their overshoes and their thin wool gloves (even though I slipped my road gloves on over them.) I also have their thicker weight gloves but haven’t really used them enough to know who cold they stay awesome to.