The Gran sport has a ton of clearance for pretty large tires. When I bought mine it had knobby 27x1-1/4 in tires and still had room for fenders. I wanted something sportier so I put 27x1 panaracers on it.
Here is a picture of the 27x1-1/4 Kenda tires mounted:
Here is a picture of the 27x1 panaracer tires:
__________________
|^^^^^^^^^^^^^^| ||
|......GO.BROWNS........| ||'|";, ___.
|_..._..._______===|=||_|__|..., ] -
"(@)'(@)"""''"**|(@)(@)*****''(@)