Why are bike tires so narrow and large diameter compared to car tires? What tradeoffs are here exactly? Motorcycle and some ebike tires are more similar to car tires than to bike tires, so i guess it has something to do with braking length at maximum expected speed, and probably also with weight of vehicle, as to not exceed some specified pressure on road. There has to be so many more reasons (weight? air resistance? some other things affecting efficiency or safety? ???)
update: apparently friction involving things that are bendy is monstrously complicated subject, and also there are material limits like maximum allowed shear stress
Gyroscopic effect for bicycles is neither significant nor necessary. How are bikes with 12" wheels or less going to take advantage of that? There are some functioning bikes on this page whose gyroscopic force would be less than 1% of the mass of the bike and rider. They’re certainly a contributing factor, to varying degrees, but even on bigger bikes they aren’t substantial. Some guys at Cambridge went out of their way to prove that.