Winter Clothing 101
The science to staying warm on those cold weather rides
By ED SASSLER, coach for the Harvard University Cycling Association
You've probably heard the most common advice - dress in layers. They never really explain the layers, so I try to. I break winter clothing down into three layers, and then deal with the special areas as needed. The three layers are wicking layer, thermal layer, and isolation layer. Each layer has a specific job to do, get them in the wrong order and it can't work (sort of like trying to put the insulation on the outside of the walls).
Wicking layer: You need to keep your body warm, but your body is also trying to regulate itself, so there's moisture. The wicking layer's job is to pass that moisture to the outside, away from your skin. The mountain climbers' saying "cotton kills" comes from the fact that cotton absorbs water and acts like a wall against wicking. The thing that most people don't get about the wicking layer is that it's NOT warm. Wicking doesn't work across a temperature drop, if it's body temp on one side and 20 degrees colder on the other side, it's just not going to work well. The insulation or R factor comes in the next layer - don't let the marketing fool you.
There are lots of winter jackets that say they pass moisture to the outside, have you ever seen salt build-up on a winter jacket on a cold day? The reason I point this out is because your body will keep producing moisture, and at some point the wicking layer becomes saturated. The amount of wicking you need is based on the time you plan on riding. For short rides you can get away with a thin layer; longer rides you're going to need more. This is based on the individual, and everybody has their problem areas - if you understand the wicking layer's job you can make it work.
Thermal layer: This is much like the insulation in your walls, thickness = R value to some extent. Think of this as a dead airspace, if air is warm, trapped and not moving, this layer is doing its job. This is the layer that most people have, the wool sweater or polar fleece top - all good stuff. Where the
wicking layer is based on time, the thermal layer is based on temp. On either of these two layers I like the thin/thick/both method of getting the most for your money. If you have one thin layer and one thick layer you have three temperature ranges, which should cover almost all of your riding needs.
tIsolation layer: If the thermal layer is the dead air space around your body, and you're moving, something has to keep the wind out. The isolation layer's job is just that, keeping the wind out, with the ability to regulate using the zipper. No ability to vent and you'll feel like you're in a steam room, until you cool down and then you'll feel like you're in an ice storm. The cut of the isolation layer counts, I've found very few all-purpose jackets that do what a cycling jacket is asked to do, but some of the new cycling jackets can be worn anywhere.
Hands and head: Hands and feet are always a problem. For hands, I have a bunch of different gloves for different conditions, but they all have one thing in common - room for glove liners.
Glove liners are basically a wicking layer for your hands, but as they add thickness, they also add some R value. Here's a little trick: get two pairs of glove liners, keep the second pair in a back pocket. After you stop, you have two options, you can put the wet gloves back on, or you can switch to the warm dry pair of liners. Everybody else in the group will think you're a genius. For the head I've tried just about everything, and here's what I've found: you can't jam enough inside the helmet to do the job, and you don't have to. There are helmet covers that go over the helmet, forming a little greenhouse around your head. Add a headband that covers your ears and you're good to go!
tFeet: feet are a big issue for many. The common mistake is to try to jam thicker socks into shoes that were fit for thin ones. If you compress insulation you get itchy cardboard, so don't do it. If you're not using cleated shoes, find that set of boots you wear with the thick wool socks. If you are wearing cleated shoes, booties are the answer, and once again there is layering to think about. You could just throw the booties over your shoes and be off, but a lot of people find that falls short. If you buy booties slightly larger and find giant thick wool socks, you can cut a hole for the cleats in the socks, put them over the shoe and then put the bootie over that. You can even fold the end of the sock down to keep the zipper tab from flopping around, and give you Clydesdale look.
Lastly, there is the scarf. Cycling is an activity, it requires effort that requires breathing. The one inlet of cold air you can't eliminate is your breathing, but you can do things to warm both the air and your neck and chest. The scarf is the perfect item for this. It goes around the neck and tucks in right in front of the chest. They're cheap, you may already have one, and if you match the extra wool sock sticking out of your booties, you get extra style points. Note: never let the scarf hang down near the wheels.
Dressing for winter riding is a bit of a science, and it takes a while to get it all so that you're comfortable, but it does work. The up side will become clear, you can ride more of the season, and, understanding how to dress for cycling means there aren't a whole lot of things you can't be ready for.
There's a saying, "there are no bad riding days, just poor clothing decisions."