Bob Roll anyone? Ted King? Timmy Duggan? Anyone know these guys? No? Well, we do, but the point is, these guys wear hats. Why do they wear them? Because out on your bike, on that lonely road, some days it isn't all sunshine and roses, you just need something on under your helmet to feel warm, or a brim to keep the rain out of your eyes, or to protect your head. And, if you're going to wear a hat it might as well look cool...
You've got two options:
Coolmax for those hot days:
Cotton because hey, some of you know that this is old school, but still a must have piece of cycling gear: