>>1278176>>1278180>>1278183That's all just what's wrong on the surface.
Going deeper, there's the massive losses in such a system.
The bearings for the flywheel will leech away so much of the energy so quickly that it's essentially useless.
Then there's how the flywheel itself, which would have to be made of something as dense (and expensive!) as osmium in order to make any sense, would have to be absolutely perfectly balanced in order for it to (1) not lose energy to vibration, and (2) not shake the entire bike to pieces.
Next, in order to eliminate as much loss due to bearing friction, the bearings would have to be magnetic, so they're as lossless as possible. That's expensive, and not necessarily perfect or even suitable; one good hard bump, and the flywheel axle (or the flywheel itself) brushes up against something, either losing energy, or causing a catastrophic failure of the entire system -- and at the speed at which it rotates, it would likely tear itself to pieces -- and the bike and *the rider* along with it!
Finally, *air resistance* is also a source of friction, leeching away rotational energy; the system would have to be completely enclosed, hermetically-sealed, and as close to a total vacuum inside as possible.
Possible to do, but heavy and expensive.
Just as a back-of-the-napkin, hand-waving calculation, I'd say the whole flywheel system would end up massing in the neighborhood of 25kg (or more). It would out-mass the entire bike by a factor of at least 4 or 5.
Furthermore the 'flywheel effect' of a rotating mass that large and fast would make the bike itself impossible to maneuver; you'd try to take a corner or curve, and the forks would turn but the bike would keep going straight, and you'd crash; it also wouldn't want to lean over in a curve anyway.
As previously stated, one good hard bump would probably ruin the whole assembly.
It's just not practical. OP is either a troll or just not very smart.
