Short ride of a mile to the local coffee shop or brewpub, long ride of 400 km/day on a brevet. I don't really find my rhythm until about 40 miles; sometimes it doesn't happen at all, but when it does it's pretty sweet. I think it's a matter of finding equilibrium. From there, the perfect ride is one where I can maintain that balance with fueling, hydration, and pacing all day long.