I run the 61cm version of this exact frame and run 23's. With my gearing the rear axle is very close to the front end of the dropouts and there's not much clearance between the tyre and seat tube...
As Tomasito says above i suppose it depends on where your axle sits in the dropouts and how much this shifts if you intend to run flip-flop? Your right in that the chainstays look like they have plenty of room for wider tyres but i'd keep an eye on the seat tube clearance with your current gearing.
I run the 61cm version of this exact frame and run 23's. With my gearing the rear axle is very close to the front end of the dropouts and there's not much clearance between the tyre and seat tube...
As Tomasito says above i suppose it depends on where your axle sits in the dropouts and how much this shifts if you intend to run flip-flop? Your right in that the chainstays look like they have plenty of room for wider tyres but i'd keep an eye on the seat tube clearance with your current gearing.