four season cycling

Fourth Season Skills is a series of articles about riding bicycles in the winter. Topics will include everything you need to know about equipment choices, clothing, riding skills, and how to stay warm. Even in the harshest temperatures. I will draw on my many years of experience living and cycling in Northern Minnesota. I have commuted by bike in all four seasons for 12 years. I am a veteran of the Arrowhead 135, one of the hardest winter races in the world. I am a winter camper and winter camping instructor.

Ground blizzard during a commute to work.

You choice of clothing is one of the most important parts of being comfortable while riding in cold weather. It is possible to be comfortable, meaning warm, in almost any temperature once you understand the basics of heat loss. And then wearing clothes to help prevent the loss of heat.

There are four basic ways heat loss can happen:

1) Radiation: example-uncovered head or lack of insulation

2) Conduction: direct physical contact with something cold. Example: bare metal, water, sweat soaked clothes, rain.

3) Convection: Your body generates heat to keep the layer of air directly next to your skin warm. Your clothing maintains this warm layer by trapping it in the dead air spaces of fabric. That warm air can quickly be stolen by wind if proper shells are not worn.

4) Evaporation: Perspiration-heat is required to disperse vaporized moisture. Breathing causes the displacement of warm moist air by cold dry air.

Today I’m going to talk about convection. Your body works hard to maintain a core temperature and in turn a layer of heated air near your body. Your clothing choices, if done thoughtfully, insulates or traps that layer of heated air next to your body. A top layer that is windproof further helps to hold that heat in.

I always tell people when the temperature drops below the freezing mark I will pay as much, or more, attention to the wind speed then to the air temperature. The wind is what robs your body of the heat you are producing. The wind will pull heat out of every little opening in our clothing. Or through your clothing if it’s not windproof. Your body responds by working harder to maintain the layer of heated air next to your body. The higher the wind speed, the quicker the heat loss. You should also factor in your speed on the bicycle.  For example, an increase of speed on a downhill increases the overall wind speed. This creates an elevated level of heat loss during the descent.

From my experience I have found that it’s easier to maintain warmth with an air temperature of say 5F/-15C degrees with no wind as compared to a much warmer air temperature of 32F/0C degrees with a wind speed of 25-30 mph.

Yes, there are times when it is easier to stay warm when the thermometer is reading 5 degrees then when it’s reading 32 degrees. So always pay attention to the wind speed when planning what you are going to wear for your next fourth season bicycle ride.

Next on this series: Strategies for dressing to maintain a comfortable level of warmth.