I read once that a university study looked at cyclists and swimmers who shave their bodies to understand how it affected "drag" in the water or on the bike. They concluded that it had NO discernable difference in performance.
However, many cyclists shave or trim the hair because when you fall off or crash on your bike, there is nothing worse than trying to pick hair out of a wound.
Also, the feeling of the wind or water rushing past you on hairless skin is impossible to explain - erotic even.
I cycled for years and have great legs (not being conceited - it's just true) and clip them very short in the summer. I don't shave because of ingrown hairs. However, when I see a great pair of shaved legs, I'll often walk or drive a few extra blocks just to appreciate them.
Guys - nothing about shaving your legs makes you a sissy. Well developed calves and quads are a trophy of incredibly hard work. Go and tell a professional triathlete that he looks like a girl because he trims his body hair and he'll probably tell you that you're an asshole.
A man should be judged on his character, his honesty, his intelligence and his commitment to family, friends and passions, not his body hair, or lack thereof.