As a recreational rider in the 70's a bike shop put me, correctly, on a 61cm frame. But I had to run with and look just like the fast crowd so I spent the 80's and half the 90's on a 58 cm frame. I came to the realization that I was really a recreational rider and have happily returned to a 61cm frame.

I think it's a little bit hard to know where you are going to find yourself on the arc of a life spent cycling especially in the first year. Even harder for the clerk in the bike shop talking to you when you go to buy that first bike. To newcomers to our bike group we just tell them to grab a bike, any bike, and come ride with us; we'll figure things out as we go along.