Originally Posted by
Moisture
HTupolev is this why I feel like I can go faster on a 12 or even 13t final gear?
Probably not. If you're spinning downhill at 35mph, getting an extra half-watt of power is going to speed you up by like a one one-hundredth of a mph or thereabouts.
Actually, since cassettes with 11T small cogs just about always also include a 12T and/or 13T cog, I can't think of any obvious reason that you'd see any tangible downhill performance loss versus a cassette with a 12T or 13T small cog. It would only be a "problem" if you're pedaling it in situations where you'd be better off either switching into a lower gear or tucking and coasting.