On what exact date was Drais's invention first publicly presented as a successful, steerable, two-wheeled personal vehicle?

Answer

June 12, 1817

The milestone moment for the machine occurred on June 12, 1817, when the German inventor presented his creation, marking its first documented successful operation.

On what exact date was Drais's invention first publicly presented as a successful, steerable, two-wheeled personal vehicle?
inventordesignmachinepedalbicycle