I've been on a few comfort bikes today, Fuji, Giant, Diamondback and Jamis. All were medium frame size. Now I've found a Trek that has a 20" frame, and don't know if that will be too big? Any suggestions? This is all new to me.

size is Typically the seat tube length,, along with the taller seat tube the top tube, reach is a bit longer ..

to properly judge a frameset fit, you need more measurement data.

If there is a sloping top tube the level line as if it were a horizontal tube , which is a virtual top tube.. length,

Yo Scolist, I grew up on the Highland side of the river and still have family there. Four years ago I knew nothing about bikes and fit but was lucky enough to go to a reliable bike shop that put me on the right size bike. Not only was the bike sized correctly but the model was versatile enough to outfit for light touring with a rear rack and panniers. I hope you have that kind of bike shop in PK. Google for the local bike club and ask members on their web site - they will know who is reliable.

Berner, You are going to have to come back up. The old railroad trestle is now called Walkway Over The Hudson. Bikes are permitted. And it's free!