Originally Posted by
Iride01
I'm skeptical of anything that points to body proportions too. I'm supposed to be on >175 mm cranks based on my 34.5" (≈88 cm) inseam. Yet I ride 165 mm cranks.
Unlike you, I like to spin a fast cadence and put out little torque. So it stands to reason that my choice of cranks will be different than your choice.
To borrow Sheldon Brown's analogy, it's a lot easier for a tall person to climb small steps than it is for a short person to climb tall steps.