Originally Posted by well biked

Schwinns were generally measured in inches, center to top, with sizes often available in 2" increments (although sometimes 1", depending on the model, etc). My guess is 25" for that one, so that would be around 63cm. The head tube is noticeably longer than on my 23" '80's Schwinn. And I've seen some 27" Schwinns, and they're noticeably bigger than that.