28 as of Sat. I got into biking (other than just riding my bike around campus) a little over a year ago when I realized that biking was the only way I was going to keep my pos-ACL reconstruction knee strong so i could do the other things I wanted to (ie. skiing). Found a nice Trek 1500 on craigslist, and have been biking ever since. Just now starting to look at upgrading to a nice new bike when i start working next fall (just finishing up graduate school).

I would guess that $$ is part of the reason you don't see a lot of the younger group. This is an expensive sport! and most of us are just getting out of school and doing that whole first job thing.