Got it, hope that helped! I'd be very interested to see what the analysis is for a bike and what the optimal human efficiency is like. In my experience riding

Got it, hope that helped! I'd be very interested to see what the analysis is for a bike and what the optimal human efficiency is like. In my experience riding road/hybrid bikes vs. mountain bikes, the lower resistance tires reduce the effort even if the gearing is similar. I'm also guessing the human leg has a narrower efficiency range in terms of RPM and power produced, so bikes usually have 15+ gears. Now that I think about it, the 'simplest' way to explain the curve is - the vehicle/powertrain variables determine the efficiency curve with ideal gearing e.g. a CVT. If you have a 4 speed transmission, you choose 4 optimal points and imagine a steeper efficiency fall off in between each point (4 flattened parabolas with vertices at the optimal points).