If you're going to ride only above freezing and in the dry, there isn't an awful lot you have to do.
You already know you make your own heat. that's half the battle right there. It helps if you think, not of keeping warm, but of managing heat and sweat. The idea is to remain cool enough that sweat does not become an issue. In that regard, cycling at 10°F is no different than cycling at 110°F. The difference is that you'll want to retain some
The general principle is to underdress slightly, then use the heat generated by pedaling to keep warm. The standard advice is that when you step outside, you should feel a chill. If not, you're already dressed too warm.
Then, you should feel cool for the first two or three miles. If you warm up before that, you're dressed too warm.
In low, yet above-freezing temps, starting from the top, I use a cycling skullcap under my helmet.
I don't own any long-sleeve jerseys. Instead, I'll wear one or two long-sleeved wicking t-shirts under a regular jersey. Add armwarmers as needed.
Alternatively, on my commute, I wear a cycling-specific jacket over a single wicking long-sleeved t-shirt. Cycling-specific jackets have are cut to fit when you're riding the hoods and drops, with gorilla-length sleeves, a shaped neck, and a long tail. They also have extra venting options. Most have at least pit zips that open and a rear vent.
There are four things I look for when buying tights.
- Wind-front tights. Plain tights only seem to filter the breeze as it passes through them.
- No pad. I wear them over my shorts. This way, not only do I have a double layer for the boys, but I don't have to wash tights after every ride.
- Bib-tights are a must for comfort. Two sets of elastic waistbands squeezing the same place makes it uncomfortable for me. I don't mind regular shorts, but I can only wear bib tights.
- Contoured or articulated knee. Particularly when layering (below-freezing), this helps prevent binding across the kneecap, and bunching in the back.
If cycling only occasionally, and only above freezing, you can probably get away without numbers three and four. Nashbar makes some inexpensive windfront tights.
I also use wind-front gloves. Cannondale makes nice ones--their Slice glove. Around the mid-20s is where I change to double-gloving. I wear regular summer-weight long-finger gloves inside a larger pair of wind-front gloves.
On the feet, there are two things to consider about your regular summer cycling shoes.
- They're designed to keep your feet cool. You have to work against their design to keep your feet warm.
- You probably have a nice, snug fit. This eliminates the possibility of wearing extra or thicker socks. It's the extra air space that keeps your feet warm. Compress that out, and you get cold feet. Plus, extra socks inside tight shoes compresses the blood vessels that supply heat to your feet. Double whammy.
I advise a second pair of cycling shoes for winter. Above freezing you'll certainly be able to get by with a cheaper (read: less well ventilated) three-season shoe, a size or two larger to accommodate warmer socks, then booties to keep the wind and wet out.
Going below freezing, then into the single-digits requires more stuff, and some different stuff, but the principle remains the same, managing heat and sweat.