i use a couple of icebreaker jerseys. the wool is slightly thicker in the front to help deal with the wind, and thinner in the back to release heat. i love 'em! wear the short sleeves in anything from 60 degrees upward into the 90's.

my 1st ride wearing one it was soaked through ... i never knew it though until i got home and took it off. no discomfort at all during the ride.