Turns out we don’t know how does a bicycle work. Imagine that..
The thing which was invented at the start of the 19th century and which we see everyday is still a mystery for the scientists.
A bicycle is surprisingly stable for an upright, two-wheeled vehicle that needs to be propped against a wall when it’s not moving. But perhaps a bigger surprise is that no consensus exists on why the bike is as stable as it is. For such a simple design, which almost anyone can understand, this seems crazy. After all, we live in a world of self-driving cars and safe passenger airplanes. Surely the bike can’t still hold any physics or engineering mysteries.
There are two theories as to how the bike keeps itself upright. One is the gyroscopic theory, where the spinning wheel provides enough stability to stop the bike from falling. Striking as this effect is, it doesn’t account for the bike’s self-balancing ability. By mounting a second wheel that spins counter to the first, the gyroscopic effect can be canceled out.
The second theory, The “caster theory” considers the bike wheel to be like the caster on a shopping cart. On a shopping cart, the caster touches the floor behind the steering axis. In this case, the steering axis is the spindle that connects it to the rest of the cart. This, as you know, lets the caster automatically align itself to the direction of travel.
The problem is that while caster trail does determine how easy a bike is to ride, and the gyroscopic effect does help stability, neither is responsible for the self-balancing effect of the bike.
So you can definitely say that science is strangely weird and we should appreciate the people who are putting so much effort to make our life easier by understanding this crap.