I'm not an engineer
Hi Charles,
I have no concrete evidence why I feel that 700C wheels would be faster other than past experience with bicycles in different configurations. 700C wheels certainly can feel faster, but that's not enough to support the idea that larger wheels are faster. I used to ride a 650c equipped Cannondale, and it was certainly fast and nimble with its small wheels.
If Pedro opts to use the same cassette and the same chainrings, then the 700C will be faster per a given RPM and as the gearing will in effect be higher with the larger wheel diameter, i?f tire pressure and rolling resistance remain unchanged.
I may be wrong here, but I really don't care either way. It's Pedro's bike, and I am just agreeing the 700C would be a worthy upgrade.