Thanks, all, for an amusing thread. My very first bike as a kid was a hand-me-down from my mom, a girl's blue and silver Western Flyer with a tank and a torpedo headlamp with the red and green lenses. I hated that it was a girl's bike then, but boy, I'd sure ride it now.
I think the notion is silly that one's masculinity could be represented as something as limited and disposable as a "man card". Masculinity is a characteristic, not an id card.
A Real Man doesn't give a &%#*#!! what anyone thinks about his vehicle. That Raleigh Sports girl's bike, if it's your size, will be enhanced by the fact that you are riding it.
(Edit - I see jds beat me to it.)