Most Helpful Guys
It's a sign of masculinity. A man who rides a motorcycle is more likely to be manly, alpha, responsible, brave, etc. things many women find attractive. It's not the motorcycle in and of itself but its a likelihood. Say 6 out of 10 men on motorcycles are manly bad asses and out of the general population its 2 out of 10. Make sense?
Most Helpful Girls
I think most motorcycles are too loud and obnoxious, I can't say I have ever been attracted to the biker type.
Yea if you ride a motorcyle thats fine whatever but if you cut in front of cars and go super fast with a loud engine your a fag