I tried one time to ride with short and got the worst burn of my life. The engeine was kicking out some serious heat, I was only going to get gas, and it was the worst thing I have ever done. I used to ride in just a T-shirt, but now during the warmer part of the year I wear 661 gear. Actually I wear my 661 gear until its damn cold, just above freezing, then I switch to me icon jacket. I went down on the 405 freeway doing about 65 or 70 before getting side swipped by a car, walked away with only a seperated shoulder. Its never to hot for gear.