Categories: Accessories and GearReverence

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.

frank

The founder of Velominati and curator of The Rules, Frank was born in the Dutch colonies of Minnesota. His boundless physical talents are carefully canceled out by his equally boundless enthusiasm for drinking. Coffee, beer, wine, if it’s in a container, he will enjoy it, a lot of it. He currently lives in Seattle. He loves riding in the rain and scheduling visits with the Man with the Hammer just to be reminded of the privilege it is to feel completely depleted. He holds down a technology job the description of which no-one really understands and his interests outside of Cycling and drinking are Cycling and drinking. As devoted aesthete, the only thing more important to him than riding a bike well is looking good doing it. Frank is co-author along with the other Keepers of the Cog of the popular book, The Rules, The Way of the Cycling Disciple and also writes a monthly column for the magazine, Cyclist. He is also currently working on the first follow-up to The Rules, tentatively entitled The Hardmen. Email him directly at rouleur@velominati.com.

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Ron says:

Jul 31 2012 at 7:16 am

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.
frank says:

Jul 31 2012 at 7:19 am

@ChrisO

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.

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.
frank says:

Jul 31 2012 at 7:25 am

@Marko

Try the Un D Lite, dude.

@brett

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.

Word.
PeakInTwoYears says:

Jul 31 2012 at 7:26 am

@frank

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.

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.
frank says:

Jul 31 2012 at 7:26 am

@ChrisO

@Marko

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.

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.

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.
tessar says:

Jul 31 2012 at 7:28 am

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.
tessar says:

Jul 31 2012 at 7:42 am

@frank

@ChrisO

@Marko

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.

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.

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.

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.
frank says:

Jul 31 2012 at 8:27 am

@Ron

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.

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

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.

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

@frank as Velominati Official Thermal Regulation (OTR) partners, will we be seeing some nice V-Cogged base layers, woollen Kneekers, Armskins and the like?

Yes!
Chris says:

Jul 31 2012 at 8:40 am

@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.
frank says:

Jul 31 2012 at 8:41 am

@tessar

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.

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.