Your drawing shows that a bicycle touches the ground in small places. It can lean away from that narrow support. A stopped bicycle cannot simply keep rolling its wheels into a new position.

When a bicycle moves, steering changes where its wheels travel. A rider can make small corrections that help bring the wheels under a lean.

That is one useful clue, not the whole explanation. The arrangement of the parts and their mass, meaning how much matter they contain, also affects how a bicycle responds. Some bikes can even steer themselves toward a lean under suitable conditions.

Your block test investigates support while stopped. It does not show steering or explain everything that happens while rolling. A good model has a job and a limit.

One familiar explanation says spinning wheels keep a bicycle upright through a gyroscopic effect, a way spinning objects respond when their direction is changed.

Researchers tested whether that effect was necessary. They built a special bicycle designed to remove it and another familiar steering effect.

Under the test conditions, the bicycle could still stay upright while moving without a rider. That was a counterexample: an observation that a claim said could not happen.

The test did not show that spinning wheels never matter. It showed that wheel spin could not be the only explanation needed. An everyday object can still give researchers a new puzzle.