BillyShope
Automotive
- Sep 5, 2003
- 263
Not really a "Helpful Tip," but there's no "Interesting Trivia" choice.
The simplicity of the old Ford torque tube suspension (used in the first half of the last century) is to be admired. It actually reduces to a triangle with 3 links: The axle assembly, the Panhard, and the rest of the car. Now, you expect to find triangles in bridges and such, but mechanisms designers generally avoid them. Ford's design (yes, I know it was used by others) manages to incorporate the necessary suspension restraints and articulation within that simple triangle.
But, as I recently admired it anew, I suddenly realized that the simplicity came at a cost which few would accept today. While many reference books show the torque tube roll axis on the car's centerline in plan view, this could not be the case. It is simply not possible to rotate one side of a triangle about the midpoint of an adjacent side. Essentially all of the body roll would be about the one axis of the triangle. In other words, it would be about a line passing through the front ball and the pivot at the chassis end of the Panhard.
This would mean a roll axis at a considerable angle from the car's centerline and, consequently, it would also mean different roll steer characteristics depending on turn direction.
Perhaps we shouldn't worry so much about roll axis migration.
The simplicity of the old Ford torque tube suspension (used in the first half of the last century) is to be admired. It actually reduces to a triangle with 3 links: The axle assembly, the Panhard, and the rest of the car. Now, you expect to find triangles in bridges and such, but mechanisms designers generally avoid them. Ford's design (yes, I know it was used by others) manages to incorporate the necessary suspension restraints and articulation within that simple triangle.
But, as I recently admired it anew, I suddenly realized that the simplicity came at a cost which few would accept today. While many reference books show the torque tube roll axis on the car's centerline in plan view, this could not be the case. It is simply not possible to rotate one side of a triangle about the midpoint of an adjacent side. Essentially all of the body roll would be about the one axis of the triangle. In other words, it would be about a line passing through the front ball and the pivot at the chassis end of the Panhard.
This would mean a roll axis at a considerable angle from the car's centerline and, consequently, it would also mean different roll steer characteristics depending on turn direction.
Perhaps we shouldn't worry so much about roll axis migration.