Several years ago, we began promoting the use of a shorter length crank arm for all bike riders. We were met with strong resistance initially but as a few of the pioneer riders tried them and realized the results, they started to gain popularity. After using different length arms, testing hundreds of riders, mapping the race results and compiling feedback from many, many fitters and coaches, we are certain that there is still not “carved in stone” answer for the “best” length. But what we have devised is a chart that accumulates and represents most of the key elements for shorter crank length choices. One of the key elements are the riders’ watts, this number really helps drive the chain ring choices. Another number is a rider’s seat height, that along with normal riding terrain will help you zero in on the best choice for you. Things like shoe size (toe overlap) matter and you will see that there is a lot of overlap in the size ranges. In general, though, don’t be afraid to go shorter, there are many fast 6’4’ racers using 145mm crank arms.