>Weight: a bus which can carry 20 persons and has a range of 2 km (1.2 mi) requires a flywheel weighing about 3 tons.
>The flywheel, which turns at 3000 revolutions per minute, requires special attachment and security—because the external speed of the disk is 900 km/h (560 mph).
>Driving a gyrobus has the added complexity that the flywheel acts as a gyroscope that will resist changes in orientation, for example when a bus tilts while making a turn, assuming that the flywheel has a horizontal rotation axis.
So you have a giant blender than can travel one mile in a straight line before needing to be recharged
I personally think Battery buses with SAE J3105 'docking' points at key stops (basically, the stops that are used to loiter to set timing, rather than leaving as soon as possible) is a better solution than the cost of stringing OHL through every major road in a city.
Reading about this and matching it up with what I see in some more recent electric truck and ferry charging videos I feel this is almost historic tech.