I also think that bike=machine=technical=male thing plays a role
I think this has alot of influence for women who don't want to cycle + the fear of looking dorky/out of shape against the young males in spandex.

I think it is also true for some men...who want to get back into shape and I know for certain some like bikes, because they are geeky-techy-mechanical guys.

How I try to explain to some about bikes..is to tell them, a bike is like a sewing machine. I meann hey, a sewing machine requires understanding it, how to use it, it is technical and sewing/tailoring well, does require logic, some technical details (and artistry abit). And I use sewing as something totally different metaphor, but has been traditional viewed as "women's stuff", but can be intimidating to people who don't like it/intimidated by the details.