Given that Im am not a power rider, but try to do a min. 5 mi./day on our country town road with some lowish, rolling hills, that is, we arent flat and we arent hilly, I get a varied workout and a good feel for what rations are working. My bike for 'serious' is a Trek 7200, set up 'English', but it doesnt count here. The ones that Im talking about are the '72 BSA 'Pubman' with a SA sgl. spd. coaster and 46T chainring and several 'cruisers' with 44T c-rings. Ive collected 16, 17, 18. 19. and 22 tooth rear sprockets which interchange between all, and swap easily. Given me and the road, here is what Ive found. The 16 is pretty tall, when you are feeling strong and on the level or wind at your back, you fly along briskly. I fade pretty quick when I hit the grade or headwind (or, worst of all, a grade AND headwind!) I can do it, but it is work. The 17 cuts that pain and suffering, and it is kind of a tossup between it and the 18 for a nice all rounder. The 19 is nice if there is a headwind when I leave, but the cadence is a little too quick for an all rounder for me, though I think I would probably like it in town. The 22 is a spinner, slow and powerful (did I say slow) and would probably be pretty good if I went off road some, but I like pavement now. Without messing with the chain lengths I have been able to go from a 22 (axle up close to the end of slot) to a 16 (but the axle was wayyy back, virtually no chain adjustment left) on GT Dyno Deuce. Other bikes/adj. will likely vary. I think if you set up for a 19 up close you should be pretty good to go to the tall 16. Maybe this will help some of you during builds to get an idea what sprockets to initially try out and not have chain length woes later.