At the end there is some text "sinusoidal characteristic". This is a control system, and (unlike the system of a bicycle) with increased speeds it will go unsta

At the end there is some text "sinusoidal characteristic". This is a control system, and (unlike the system of a bicycle) with increased speeds it will go unstable, the oscillations will continue to increase uncontrolled. This is why faster trains are an engineering accomplishment worth displaying. They require flatter cones which then require straighter track built to higher specifications.