Winter riding is something I’m passionate about because I’ve lived in New England for decades, and my cycling performance in season is based on my base training over the winter. I ride year round, adverse conditions just make it more interesting. To be able to say that I’ve had to learn to adapt to conditions – I need to dress the part and I need equipment that’s up to the task.
Lots of people say they really ride in the winter, few do. That’s probably because people have this concept about what’s normal and what’s crazy. What they call riding in the winter is normal, what I do is called crazy. As of late I’ve noticed that clothing companies make winter clothing for normal people, but claiming that they make clothing for all conditions. Here’s a good example:
This is Pearl Izumi’s system of winter dressing, and here comes my response:
Pearl Izumi’s “system of dress” is based on temperature, humidity and effort level. The amount of time on the bike doesn’t enter into their formula – how can that be? There are also a few thermodynamic laws broken… Their system is based on two types of base layers, their transfer base layer or their merino (wool) base layer, and their merino (wool) thermal layer. They never explain the layering system in terms of temperature or time on the bike (I’ll get to the moisture bit later), so I will.
The wicking layer moves moisture away from the skin – this much they got right. It has it’s limits. Wicking doesn’t work across a temperature drop. Your body is 98F, let’s say the outside temperature is 30F, moisture is never going to make it out of that system, no matter what the tag on the jacket says. For the wicking layer to work it can’t be thermal. In other words, your base layer should be at body temperature to work. What’s more if you are on the bike for a long period of time, the moisture you produce will saturate the layer. To keep this from happening, the thickness of the wicking layer should be based on the time on the bike. It’s important to understand that the wicking layer isn’t thermal, it keeps you dry, not warm.
Thermal layers are simply dead air. Insulation is gauged by R value, which is the thickness of the dead air space. The thermal layer will see a temperature drop, so it may absorb some moisture, but it’s not going to pass moisture to the outside. The thermal layer’s thickness is based on the temperature.
The outside layer is what I call the isolation layer, it allows the rider to control how much air movement reaches the thermal layer, from fully closed to somewhat open. Pearl Izumi likes to use the term “waterproof breathable”, I have not yet found that material. Material is either windproof or it’s not (putting your mouth up to the material with your hand on the other side and blowing will tell you if it’s windproof). Garments have zippers of vents, or they don’t. The arms and body allow for air movement or they don’t. That is what you have to work with in an isolation layer.