You hit it right on the head Bob.  Can't believe I'd forgotten the difference between radius and diameter.  Thanks a bunch!!      M

I'm new to N and am confused by the Bachmann EZ-track radii sizes quoted online.  I need to buy more and see 11.25", 15" and 19" quoted, but don't understand what that means.   I have two different sizes in hand right now (used, so no packaging to tell me the radii size).  One yields a radius of just under 2 feet and the other just under 3 feet when I hook them together.

Can someone please set me straight on this curve radii sizing thing so I know what to buy?  Also, is there a good website which sells EZ-track in quantity at a decent discount?

Thanks a bunch to you experienced hands for your help on this!!