TMS Bicycle, stable without gyros or trail (TMS=two-mass-skate)

There was still active research into why bicycles are stable as recently as 2011. Here's a talk about that research: ▶ this video If the bicycle was some sort of "obvious" machine, people wouldn't still be studying the basic stability mechanics 200 years later. Very few things are as simple as they seem. Even levers can get a bit complicated.

I don't think either of us understands that experiment. Fortunately, actual engineers have proven that bicycles don't stay upright from gyroscopic effects. [0] [1] If you want to experiment, try riding a bike that can't be turned. You might want to wear a helmet for that one. [0] link [1] ▶ this video

[1] Explanation of the research in question behind this article, as well as a demonstration of the bike they based the research on. They very clearly describe (at the end of the video) that even with gyroscopic and tracking forces removed, the two most important factors are where the center of gravity is, and the tendency to turn into a fall (arguably just the second, but it is caused by the location of the center of gravity with regards to the pivot). [1] ▶ this video Edit: more info on the TMS (two-mass skate) bike at its wikipedia page: link

We do know, here is the paper that the journalist refers to: link And here is a great video by the author: ▶ this video Short answer: "a bicycle should turn into a fall."