[kickstand]

Try a different seat, something wider perhaps and see if the numbness changes in any way, or gets better or worse. Numbness is caused in some cases by compression of nerves, often when sitting, and obviously as far as biking is concerned that's a main point of contact for your weight.

I've wondered about this, though I've been using the same saddle for a few years now, I have it on all of my bikes.