"F. Russell" writes:
I want to make a simple and straight walking stick from
a 1 inch diameter wooden dowel.

The stick will be straight, that is there are no bends
for a hand grip.

Rather that relying on friction alone to grip the stick
I want to add a flanged grip that will allow me to
apply a downward force to the stick without using friction.

A flanged grip would be similar to this:

http://www.gripworks.com/injection_m...ered_grips.htm

The problem is that these grips are not the correct size
and must be purchased in bulk. Bicycle handlebar grips
are also too small in diameter to fit a 1" dowel and
are also not rigid enough to withstand the force applied.

Does anyone know where I can obtain such a rigid flanged grip
that will fit over a 1" dowel?

You can always reduce the diamater of the top end of the dowel
sufficient to fit your chosen handle.