Normally I ride on my 38t chainring and use all of the gears on my 13-21 6-spd freewheel, but mainly the 13, 14, 15 and 17. I'll switch to the 48t chainring if I have a tailwind. BTW, I have the 28t chainring for up bigger hills. (gotta love a triple crankset!) My bike's original double crankset was 51/39 and I found myself mostly wanting the cross-chaining 14t on the 14-28 five-speed freewheel. Going triple opened up my gearing to what I use most - especially now that I've gotten a bit older...