Joined: Sep 2009
Posts: 2,067
Likes: 73
From: USA
Bikes: 84 Pinarello Trevisio, 86 Guerciotti SLX, 96 Specialized Stumpjumper, 2010 Surly Cross Check, 88 Centurion Prestige, 73 Raleigh Sports, GT Force, Bridgestone MB4
That is a 52cm frame (20.5 inches center to center).
Some companies measured to the top of the seat tube, most or many measured to the center of the tube intersections including for the seat tube.
Of course this difference in measuring is confusing, some might call that a 21 inch frame, and the thing is, it does not matter what we call it, either way it is the same frame, does it fit or does it not?
Yeah, it is a 52 cm/20.5 inch frame.
The top tube length is more telling to me, as long as I can get a seat post that will adjust out to my needs, I go by the top tube length as the more important when I compare bicycles to one another for size.
J