Originally Posted by PeteHski

Cadence and load is more a function of gearing than crank length. Shorter cranks will naturally increase your cadence in a particular gear (pedalling a shorter circumference), but shifting even one gear will more than compensate for the difference.

The only thing to consider with crank length is your preferred range of leg motion. I know of 2 very experienced fitters who both generally favour shorter cranks, especially if you are of average height or less and/or have limited joint flexibility.

One of them published a review of crank length based on various previous studies (some conflicting) and his own fitting experience with hundreds of clients. The bottom line was to go shorter when in any doubt. While there are various potential issues with longer cranks, there are very few with shorter cranks.

My personal experience is that I can’t tell any significant difference between 170, 172.5 and 175 mm cranks. I’m 6’ tall with relatively long legs.