I did a group ride that started at Atlanta Cycling a few years ago - I should call and see if they still ride from there. I was real slow, but I think I've been getting faster. I'm probably older than most of those folks, but it was still fun. I'm pretty fast on my road bike, but it lives in Miami, and I was amazed at how much slower my mtb is on the road.
Do you think the groups would look down at me if I try to ride with a mtb?