Today was the first time I've hopped back on my bike in a hot minute, and it's gone and gotten wintery on me! Today was my coldest commute since the heat's let up, a brisk 40 F with a north wind. Among the most powerful challenges facing any vehicular cyclist is clothing - hitting the exactly correct number of layers, fabrics, weights, and accessories. This is especially relevant at the extreme times of year - high summer and deep winter.
We've discussed the challenges of hot weather cycling - trying to strike a balance between coverage (sunburns), breathability, quick-drying, and good looking. Winter's challenges are completely different. There's a rule of thumb I've always personally followed but only recently heard articulated - "If you're not cold for the first mile or two, you're overdressed." The biggest reason - sweat becomes the enemy for totally new reasons. See, when it's hot out, sweat is this sticky constant companion. In winter, if you sweat, it can freeze and sap your warmth. So the goal is to be comfortably warm but never hot.
To those who know me, my winter cycling material of choice isn't remotely surprising. Wool. Wool does so many things - it breathes. It insulates, even when wet. It resists bacterial growth (meaning it doesn't smell). It also looks damn good. I like wool. Failing wool, I tend towards technical fabrics, and then blends. My fabric of last resort in all but the most perfect weather is cotton. As opposed to my preferred options, cotton doesn't dry quickly, smells, and provides very little insulation. And if it's wet, you might as well be wearing a wet dishrag for all the protection it offers. These properties do, however, make it ideal for wet t-shirt contests.
Next, there's the accessories - they can make or break both your outfit and your comfort. The standards for cold weather cycling (and I suppose cold weather outdoors activities in general) are wool socks, a scarf, gloves, and earmuffs or a hat. Your core and your legs will typically warm up - in a set of thermals and regular pants your legs will be comfortable in 20 degree weather, but without some help all your extremities will make you miserable in the wind.
All this being said, cycling in the winter is one of my favorite times of year. Those of us who ride through the winter always suffer from Spring Smugness - when people start pulling their bikes out of their garages in the spring weather, there's always some schmuck like me telling them all about what it was like a month back when it was freezing. You have the bike lanes and paths to yourself, and you get to watch the change of the seasons. Happy winter cycling!