Originally Posted by TimArchy

I've heard from several racers that there is some (probably psychological) effect of using larger/smaller gears of the same ratio.
From several independent sources I've been told that smaller chainring/cog combos give better acceleration from slow speeds. Larger combos make it easier to stay on top of a faster cadence.

These are my thoughts, unless they've already been contradicted by SB's earlier post, then someone else told me this:
The relative radii of the crank arm circle and the chainring can have some effect on the moment of the lever. And since a gearing change in the chainring requires a much larger change in raduis than the equivilent gearing change in the cog, a change in the radius of the chainring can make a difference that the equivilent change in the cog cannot eliminate. So a crank arm that is relatively much longer than the radius of the chainring would provide a larger mechanical advantage.

Of course, we are talking about instances where velocity is changing. When velocity stays constant, there would be no difference between 30x10 and 99x33. And I'm not bringing friction into the equation either, which I probably should.