The only specs I have been able to find is the 12 inch approx (cant find the specs at the moment..) front disc and 13 inch rear disc. My rear disc is definatley 13 inch, but my front disc is bigger than the rear. I have approx 4mm clearance between the caliper and the inside edge of the rim.
They have changed something but no specs or information I have found anywhere discusses it, apart from the forums of course