OP, you are well within the "normal" height range where a 172.5 or 175 will be optimal for your comfort, as you find on your other bikes. But, as explained above by Rolla and JDT, fixed gear pedal strike is why you have the 165 clown crank on your bike. It might be worth it to try a 170 on your fixed gear, especially if you can refrain from leaning much in corners. FWIW, you would need a power meter to determine whether your crank length makes any difference in your output, though people can imagine anything.