This is something I think about a lot. Why isn't there a bicycle post-apocalypse? Bicycles are some of the most efficient and durable machines. I would expect bikes to advance in leaps and bounds if society collapsed.
American. Developers.
Fuckers get too familiar with cars they can not imagine a vehicle with less than 4 wheels.
But any non-US can think of why:
1.
Motorbike is so much less gashogs, and be handy as fuck. At worst, you can just flattire the bike and roll it to hidehole instead of leaving out in public at the mercy of every lightfinger passerby. Plus the small inventory of a motorbike is a good thing for PA setting.
2. Ditto with bicycles. Zero fuel and easy to find parts, also.
3. Bicycle generators. Can you imagine it?