Is there a question in there? I can't tell.

Anyway, probably what you're looking at with the Cannondale is short chain stays. Probably in the area of 405 mm. Racing bikes very commonly have that sort of dimension and a 25c tire gets real close to the seat tube and really, really close to the front derailleur clamp if there is one there. If you're looking for more clearance, you'll need to find a bike with a 410+ chain stay. They will also tend to be on longer wheel base bikes with other geometry differences (fork rake, angles, etc.).