I have always been under the impression that I totally understood the mechanics working behind the stability of a bicycle i.e. i) the gyroscopic effect of the spinning wheel ii) weight of cycle and rider and iii) the centrifugal force acting on the CG when the bicycle follows a curve path. If the interplay between the above three major forces were balanced, the minor forces can be ignored and stability is achieved. This is how I always thought it works. But recently I read an article which says that analyzing the stability of a bicycle is not that simple and that it is one of those seemingly simple things that science cannot answer 'satisfactorily', like "why is ice slippery?". I am thinking, maybe how planes fly is also a bit like this. Even though most of the underlying principles are well understood, simulations, rigorous model tests in wind tunnels and actual flight tests are required to achieve the desired performance. I know this is trivial but might be fun to discuss.