Re: counter-steering, with numbers

[palmer@sfu.ca (Leigh Palmer)]

> 2) Can a bicycle turn be initiated by "shifting one's weight"?
> > There is agreement among those who have analyzed the problem correctly
> > that when starting to turn a bicycle from a straight course at any
> > speed whatsoever, the first thing that is done is to turn the front
> > wheel in the direction opposite the desired turn. This will result in
> > the bicycle being forced to that side, and the rider will continue in
> > the same direction as before. Thus he will start to fall over in the
> > direction of the desired turn.
>
> While I agree completely that this is a possible method (my post was, after
> all, devoted to analyzing this action in more detail), I should like to see
> any references you have which contend that it is the only method.  In
> particular, I contend that if it *were* the only method, then it would be
> impossible to ride a bike without holding the handle bars (since it would
> be impossible to do "the first thing that is done").

In the case of riding no hands the turn is initiated by waiting until the
lean and the wheel direction are fortuitously in the correct directions,
and then pedaling the bicycle so as to stabilize that condition. If you
would like an exercise to demonstrate this, just try riding a bicycle
slowly, no hands and without pedalling, through prescribed turns.

As I've pointed out, a variety of physical phenomena come into play in the
riding of a bicycle. Even aerodynamics and the gyroscopic moment of the
front wheel become significant under conditions of speed. Nonetheless,
while there may be more than one technique for turning a motorcycle, there
is only one in use by cyclists at moderate speeds, the one I described.

Leigh