Interesting. "Let’s look at an example. This year’s IRONMAN World Champion, Jan Frodeno has a saddle height of 860mm and rides a crank length of 172.5mm. This seems pretty normal and doesn’t turn any heads. We could even say that Jan doesn’t use a short crank. However, if we took the ratio of his saddle height:crank length and applied it to a smaller athlete such as Rachel Joyce or Mirinda Carfrae (both have a saddle heights around 670mm and ride 165mm crank lengths), they would need to move down to approximately 135mm crank length to maintain Jan’s ratio. If we reversed this and wanted Jan to replicate Rachel and Mirinda’s ratio, Jan would need to bump his crank length up to approximately 210mm!!!." Very interesting indeed. So ... Jan ought to be using 210mm cranks to duplicate the setups of (successful!) athletes like Rachel Joyce or Mirinda Carfrae but, no, the takeaway is that all of them should be using much shorter cranks ... who am I. Still, my opinions are very much less rooted in biomechanics science than they are in fiscal responsibility. My road racer came with 170mm cranks and I am not that inclined to replace them because the change (if I use the same quality of new parts) would cost 1/2 what the bike did. There would need to be a proven detriment to using 170's to make me spend that money and go through the hassle of installation, setup and etc.