Originally Posted by Dave Mayer

What?? No pro rides clinchers unless they are on a training ride, or it is a flat TT and their tire and wheel sponsors have a gun to their head.

On the Grand Tours, there wasn't a single rider on any stage on clinchers. Ditto with the classics.

A race with rough roads and climbing is bad terrain for clinchers. I would go with 22-23mm tubulars, due to their insurmountable weight advantage, and resistance to pinch flats. The only reason to go with heavier and less aero 25 and 28mm tires would be to add extra volume so that you can run lower pressures. The volume is only there to add protection against pinch flats. But since tubulars are basically impenetrable to pinch flats, you can ride lower pressures on smaller tires.

BTW: tubular tires are no better than clincher tires in terms of construction or rolling resistance. Clincher rims are the problem. The rims are heavy and fragile, solely because of the 2 'hooks' that hold on the clincher tire. The two hooks also cause pinch flats, and they are the reason why clinchers are scary dangerous to ride out if you have a sudden flat.