"Simon Brooke" wrote in message
. uk...
Peter writes:

jim beam wrote:

Take the wheel out, spin it in you hands and try to tilt it to
the
left or right and note the force of the steering action. This
should
convince you of its effect.
please explain. gyro reaction is _90 degrees to the applied
force_. i.e. my front wheel, spinning "forwards" tries to tilt top
rightwards when turned to the left. you seem to be implying that
gyro recation is responsible for banking the bike to the left when
steered left.

No, when you wheel the bike along holding onto the seat you steer by
banking the bike and the turn is a reaction to the bank. Banking
the
bike to the left will tend to initiate a turn to the left. But the
gyroscopic force is quite small when the wheel is spun at only
walking
speed and the geometry of the bike also results in the wheel turning
left in response to a left bank (even when the wheel isn't
rotating).

Well, just so. I agree that you can get strong gyroscopic effects with
a fast rotating wheel, but I'm completely unpersuaded that they are
significant at walking speed. So, again, has anyone done the maths?

http://scienceworld.wolfram.com/phys...recession.html

Phil Holman