Originally Posted by
awesomejack
Why have a crank set like 24-34-44? Why not have something like 24-36-50? It gives you the low gears and the high gears. Nothing is gained by having a 44 big ring rather than a 50. You use low gears in the little rings and high gears in the big ring. So why this choice?
Or why not 24-36-46?
because the high gears aren't needed when the average speed of a touring cyclist is slower than the average speed of a road rider/racer. There isn't much use having a 50/11-13 when the speeds at which you can utilize that gear with the power output used in touring is no different than getting into an aerodynamic tuck and coasting.
This is a time worn issue for bike shops when beginning cyclists would come in asking "I need a bigger gear, I'm pedaling down hill and can't pedal any faster" and that was with a 52/14, 100" top gear. The facts were the same then with a 100" gear as now with a 122" gear. The hp required to ride at 24mph with the windage of touring gear on the flats is totally outside of normal strength, obviously it'll be used on descents but the same argument holds that the hp required to utilize a speed increase at 24mph downhill is still outside the steady aerobic hp used in touring.