80's Madison Tire Clearance

[FetchPro]

I've had an old 80's Schwinn Madison I've been riding in different configurations for 16 years. For the past five years it's set up with cruiser bars a front porteur rack and a sturmey three-speed. I love this bike, but I'm wondering what the largest tire I can put on it is. It's running brakes and I just thought I'd crowd source and see if anyone has any experience running a larger tire, possibly even suggestions for a knobby that might fit so I can take it camping. I realize it's not the most practical bike for this purpose, but I'd love for it to have more dexterity as far as where it can go and what it can do comfortably. I know when I first bought it, I ran 700 x 28c Armadillos comfortably, but that was without brakes. Any suggestions or insight is welcome. Thanks in advance.

[nooneline]

If 28mm tires fit comfortably, than I'm going to go ahead and guess that 30mm tires can fit on it - brakes don't change how big of a tire can fit on the rim without touching the frame. But the best way to tell is to be the person who's looking at the bike.

[FetchPro]

Thanks, that's helpful. Any suggestions for a 28 or 30 knobby tire you like/prefer/have experience with?