Been using the Schwable "1" 700x28 clincher 245 grams, 80 gram tube on Hed Beligum C2 the last 2 months for training purposes, 90 psi front & rear, these are by far some of the smoothest rolling tires I've used, 28's probably factor into that, but up at speeds descending they are so rock solid feeling and fast I'm having second thoughts on throwing the 23's away. I think the "1"s will live up to the hype!