My desire to ride a bike during winter dwindles as the temp drops, but traditional beanies — aside from being bulky under a helmet — can feel way too warm, especially once you really get pedaling. This ultra-thin polyester skullcap has cut down on those downhill-windchills without overheating me. The material breathes (hold it to the light and you can see through it), and it dries quickly. It also packs tiny (see below). If you desire more ear coverage, there’s the previously-reviewed thermal Maxit beanie or Headsweats also makes a MidCap as well as several other thicker, more expensive options I have not used, including a few in micro fleece. As it is, I get 2/3 ear coverage with this skullcap, which is generally fine for the climate I ride in (San Francisco). Headsweats makes a cycling cap complete with a bill; I prefer being able to carelessly wad mine up and throw it in my pack, plus the lack of a bill affords other uses: I’ve donned mine with a hooded sweatshirt to play basketball and under a $.99-store beanie to add a bit more warmth. Above all else, this polyester cap makes my helmet much more comfortable.