While on the subject of replacing the cranks, I am wondering if I should go to a shorter crank. I recently measured myself and found that I am right at a 31" inseam, or maybe a smidge under; or about 78 cm. According to the web searches I have done, this is the only measurement that needs to be taken for the crank length. And according to this I should be running a crank in the neighborhood of 162.5 to 170. I currently have 175mm cranks and I find it difficult if not impossible to spin over 85 rpm without bouncing. Should I be looking at a shorter crank arm length in my search? Would these shorter cranks help me to spin higher rpms more comfortably? I am not talking about only on these hills, but all over. Is this the right way to measure, or are there any other measurements that need to be takin into account to determine correct crank length?