Well, hope you didn’t take what I said was demeaning in anyway. Those casual bikes are a different beast to ride compared to the ones you’re talking about.
As an engineer, (so I’ve taken physics, basic mechanical engineering and such) I always used to puzzle over why it was so much harder to cycle over a hill than walk over the same hill. I live in a place that’s flatter than a pool table, and my biggest hill is a bridge. I could put on a backpack containing as much weight as my bike and have less trouble walking over the bridge than riding over it. I eventually concluded it must be that friction helps us while walking but bikes are too low in friction. Too efficient.
Just a fun fact that kind of goes with this discussion. If you put people on a motorized treadmill and measure their energy expenditure while they work out you find an interesting thing. Speed up the treadmill and you find a speed where the people change over from walking to running. That speed is the point where trotting or jogging uses less energy than walking. This is completely automatic, and your higher brain never thinks about it.
If you repeat the experiment with horses and other animals, they do the same thing. At some speed, they switch from walking to running and do it to save energy.
