I am curious if you could use flywheels instead of batteries like the gyrobus (https://en.wikipedia.org/wiki/Gyrobus https://en.wikipedia.org/wiki/Gyrobus) used

I am curious if you could use flywheels instead of batteries like the gyrobus (https://en.wikipedia.org/wiki/Gyrobus https://en.wikipedia.org/wiki/Gyrobus) used in the 1950s in switzerland. The biggest problem they had was the change in direction in sharp corners that shouldn't be the case for trains. Especially with the advancement in flywheel technology like suspending them in a vacuum.