Originally Posted by CliffordK

Your speed is related to the average power.

But your maximum force is essentially related to the instantaneous peak power, and someone standing and mashing can get much higher power peaks than someone sitting and spinning. Also as mentioned, higher force with slower cadence.

Other than the effect of the pedal falling away from a person's weight, one can put get pretty close to 100% of one's weight into the downward force when standing. Putting more force into the cranks than 100% of one's weight takes a lot of extra effort.



That is pretty light.

6'4" is pretty tall.

I'm not sure the height alone would increase the force on the cranks, unless you are using long cranks. 180mm or longer cranks. Even 175mm cranks are pretty standard and should handle typical forces. The difference between say a 175mm and a 180mm crank is only about 3%... not a huge force difference. There are longer cranks, but they are rare.