My "weekend" road bike has 53/39 and 13-21. The 53x13 does actually get used, at 100 rpm that is 33 mph which is a speed easily seen on even a small downhill or - very briefly, for me - in a sprint. A 53x11 would be 38 mph, I probably wouldn't have much use for that. The small steps between cogs are nice. The 39x21 low is daunting sometimes. I wouldn't mind putting a triple on this bike.