Mr. Fly

I'm a tropical baby so I like it warm. 80's to 90's is where I like to operate. With that in mind, for temps in the upper 30's to the 50's, I typically wear bib knickers (these are usually made of Roubaix fabric), a thin base layer and a non-summer-weight LS jersey or non-summer-weight SS jersey with arm warmers.

The trick though, is to mitigate wind chill and to keep your head warm. So add a windproof vest, a neck gaiter and a skull cap that covers your ears. You may also want to use an overshoe and/or full-fingered gloves if your extremities get cold easily. This is enough for even me to go bombing down 4-mile descents without freezing up. In fact, it's warm enough that I have to unzip the vest and sometimes even the jersey while climbing.