The other day, a wheel from a curved-dash Oldsmobile was brought in to the workshop, which graphically illustrated an unforeseen problem with the old design, a little misapplication of the clutch and, well, see the picture.
Torsional forces are not catered for in the Celtic scheme, and come a-plenty with the advent of engines and brakes. The Oldsmobile case involves a gearbox, a thing which brings complications well worth avoiding, including the need to apply clutches with care if the wheel design is inadequate. In the 19th century, for reasons connected with machine production and replacement of parts in ‘the field’ when they had perhaps been blown out by gunfire, a form known as the artillery wheel had been invented.
Figure 2, the hub of an artillery type car wheel
It provided a way of addressing some of the problems which the old design showed. The principal feature of the design is that the spokes are not mortised into a wooden stock, but come together at their roots as wedges, segments, and are sandwiched between a flange and a floating plate, bolts securing them. Early cars soon began to use artillery wheels, they take the loadings of braking pretty well, and sideways forces just as well as the old kind. And they look proper handsome when they are made nicely.