I've always been under the impression that any gear combination that gives the same gear inch is more or less equal. Like, a 48x16 is the same as a 51x17 is the same as a 42x14. While there may be small differences in weight and longevity due to the volumes of metal involved, different gears with the same number of inches will behave the same.
At the track, I ride a Fuji Pro, which came stock with a 53T chainring. I use a 16 cog in the back, for an 87" gear. Seems fine to me. Then one of the guys at the track tells me that having such a big chainring will slow me down. I come back and say, "well, I've got a 16 tooth cog, giveing me a gear in the mid-80s." Blah blah blah, and the guy keeps insisiting that with a big chainring, regardless of the size of the cog, it'll be harder to do sudden kicks in a sprint.
This seems like horse****, so I argued with him. Then another guy jumped in with an argument about how the greater rotational inertia, farther from the center of the axis of rotation, would make a larger chainring more difficult...
OK, so you've got a bit of unimpeachable physics there, but the scale is all wrong. going from a 53T to a 47T is a 3-inch change in circumference. Divide this by pi and you get about a 1 inch change in diameter. This cannot possibly be enough to matter in terms of rotational inertia.
Looked at another way, if I took the chain off and put the bike on a trainer, a crank with a 53 would spin about as easy as a crank with a 42. And not a lot different from a crank with no chainring.
Am I wrong here? Somebody please let me know if I'm missing anything, or if this guy was smoking the ready rock.