Greg Farris writes:

And what, precisely, do you expect the "propulsive power" to be accomplishing
if the bicycle is stopped?

He said "when you approach stop." If the bicycle is still moving and
there is power to the wheel, it won't fall.

Do we reject, then, the notion that the gyroscopic stability provided by the
wheels in motion helps to keep the bicycle upright?

No, but kinetic energy in the bicycle keeps it from falling over. In
order to fall over, it has to have no kinetic energy--it has to stop.
But as long as there is power to the wheel and traction, it cannot
stop, therefore it cannot fall over (which would require a loss of
energy that cannot occur).

It is only a question of
"propulsive power" available to the rear wheel (specifically) while both wheels
must have "traction". As long as this is present the bicycle "cannot" fall
over.

Right. It should apply to both wheels, actually, but I haven't
considered that possibility.

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