Boom, From what you are explaining, it appears that you are saying that the tire on a dished wheel is shaped like a segment of a cone so that any given part of it contacts the road surface flat when the entire wheel is cambered. This will create the intersect points you are referring to? Lines from the cone shape tires through the axle centerline?
Dom,
The dished wooden wheel was described as a shallow cone for hundreds of years, but what was being described was the dish of the wheel; how the spokes were angled from the hub outward. As I described the wheel in Fig. 6, yes if lines were drawn following the the angle of the surface of the iron tyre extending outward from the face of the wheel they would eventually meet at a point in space and the shape described by these line would be conical. I wrote the following around four years ago when there was another discussion of the wooden dished wheel, and there are some modern automotive terms used because that was a large part of the discussion at that time.
"Camber simply refers to the tilt of the wheels as viewed from the front. If the wheel is perpendicular to the ground, it has zero camber. If the top of the wheel is tilted towards the vehicle the camber is negative, measured in degrees from the vertical. If the top of the wheel is leaning out from the vehicle the camber is positive, measured in degrees from the vertical. If you were using the term to describe the dished wooden wheel as it rode on the angled axle arm I guess you’d have to describe the wheel one half at a time. In the top half from the hub up, the camber would be positive, measuring x degrees from vertical. From the hub down to the iron tyre on the ground the wheel would have zero camber, the bottom half of the wheel being perpendicular to the ground or at least as perpendicular to the ground as the wheelwright’s and blacksmith’s skills allowed. The ideal setting to be getting the optimum performance from the wheel would be “zero camber”. A wheel that is vertical, that is riding perpendicular to the ground would give you the best tracking performance, the most tire surface to road surface contact, the least and most even wear pattern on the tread and the least pressure and force being exerted on the wheel itself, because it would be riding as flat as is possible on the ground, absorbing and dispersing the forces over a wider area and therefore causing less wear on the load bearing parts."
"Toe-in is an invention of compensation not an invention of improvement in and of itself, as you wrongly think it is. In this respect it is similar to the conical axle arm, the downward angle on the arm has to be there to compensate for the dish of the wheel, that angle is what positions the bottom of the wheel to be vertical to the ground, which is the only way the wheel can function properly. These two discoveries have to go hand in hand, they’re two parts of the same invention, one without the other would make the wheel inoperable."
The lower portion of a dished wooden wheel at the downward spoke is actually operating like a straight wheel that rides perpendicular to the ground, and it has to in order to function properly.
