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
I can speak to motorcycle tires.
Moto tires are rounded, not flat like car tires. They’re designed to provide an optimal contact patch no matter the lean angle. Often, Moto tires won’t be perfectly rounded, but come to a bit of a point in the middle. This makes for a smaller contact patch going straight, for better fuel economy, and a bigger one while turning for more traction. Finally, moto tires are often made of multiple kinds of rubber: harder in the center for lower rolling resistance, and longer tread life; softer on the sides for more traction while turning.
I’d bet that small bicycle tires share some of these characteristics, being rounded for sure, possibly others.