Re: "Negotiating" a curve. EUREKA?

[Ludwik Kowalski <KowalskiL@MAIL.MONTCLAIR.EDU>]

Hi Bob:

In the spirit of an extreme possible simplification, but
without taking away the essentials, one may consider
two identical tricycles with locked steering columns.
One with the front wheel parallel to the y axis and
another with the front wheel turned to the left by 10
degrees. The initial velocities are identical at time zero.

John_D would probably say (and I was saying the
same thing the other night) that forces in the bearing
are internal and that only external forces matter. This
would certainly be the case if the wheels were locked.
Then I realized that wheels are not rigid and that the
FBD can not be used, except for the rigid platform.
I have to think about the situation again. Reading the
books recommended by Leigh will be the first step.
Regards, Ludwik

Bob Sciamanda wrote:

> Ludwik,
> It occurred to me (while walking the Lake Erie beach) that the wheel
> communicates/interacts with the cycle frame, not only through the
> horizontal axle bearings, but also through the (almost) vertical steering
> column bearings.  In addition, the wheel interacts with you (the rider)
> through the handlebar/yoke/steering column system.  In particular, when
> you turn the wheel for a left turn, your body will turn in the opposite
> direction about the steering column; this forces you toward the center of
> curvature and also makes you lean in that direction.  Think on it.
> ( Note that this is not appealing to any "gyroscopic" effects - what I
> describe happens, in principle, even if the wheel is not rotating.)