Sorry, forgot about that! It’s an 18.5 inch seat tube (c2t), and 23.25 effective top tube so size 20” in cannondale sizing. I am 6ft 1” and rode it as in photos.(29 inches from centre of bb to top of the saddle). I reckon it’ll fit someone between 5ft 9” and 6ft best.
What size is it/height of the saddle as in the photos?