The difference in length between these choices is only about 10 precent from either direction. Think about the wide range of riders who employ these cranks. The differences in the height of these riders can be 30 percent or more. The cranklength choices available today do not really reflect a scientific approach to proportionately fitting the riders. We want to encourage all riders to understand the choices they have.
Most riders can quickly feel the differences when a change in crank length is made.
Many smaller riders utilize long cranks for a power advantage while some taller riders choose shorter cranks to smooth out their stroke. The crankarm length myth is not useful or accurate and we highly recommend personal experimentation.