True, you can run cork/cork based pads on a bare carbon rim. It's how everyone first used carbon wheels before brake tracks were engineered apart from aluminum hoops on the wheel. It doesn't give you the greatest braking power, or feel/modulation, but for a fast, non-technical course, as it was that day, it would more than suffice.
They could also have just used the best brake pads from performance based perspective, without regards to equipment longevity/re-use. These teams have the budgets to trash a few single use wheels, even if it is an Io.
I just remember reading about it at the time, that these wheels were modified for road use, but can't remember specifically what it/they were. It could've just been an axle swap with appropriate pads.
Last edited by taras0000; 09-12-17 at 08:52 PM.