Bowden conversion of the Minor braking system
Posted: Sun Mar 24, 2013 6:29 pm
This being posted for Jeroen van de Hage:
Before 1933 mechanical brakes were fitted on the Morris Minor. In order to suppress the influence of the brakes on the steering the front cables were guided by pulley causing much wear and a lot of slack in the brake system.
Replacing the originsal nude cables by Bowden cables and dispensing with the pulleys seems to be the obvious solution but now the question rises: Where to drill the hole to fix the jacket of the Bowden cable on the anchor plate?
Refrering to the drawing below, I think A is the right location to perforate the anchor plate because A lies on the horizontal line a-a, which is perpendicular to the lever when the brakes are applied, thus ensuring maximum lever moment in this state. From that point of view Q is equivalent to A but Q is located farther away from the kingpin than A is and therefore any force acting on Q will have a stronger influence on the steering than it would have, acting on A . Therefore I reject Q and I certainly reject P. Apparently there is more between heaven and earth, as a former owner of my car has perforated the brackets at P and Q and not at A. I ask this Forum: What on earth can have been his arguments to do so?

Before 1933 mechanical brakes were fitted on the Morris Minor. In order to suppress the influence of the brakes on the steering the front cables were guided by pulley causing much wear and a lot of slack in the brake system.
Replacing the originsal nude cables by Bowden cables and dispensing with the pulleys seems to be the obvious solution but now the question rises: Where to drill the hole to fix the jacket of the Bowden cable on the anchor plate?
Refrering to the drawing below, I think A is the right location to perforate the anchor plate because A lies on the horizontal line a-a, which is perpendicular to the lever when the brakes are applied, thus ensuring maximum lever moment in this state. From that point of view Q is equivalent to A but Q is located farther away from the kingpin than A is and therefore any force acting on Q will have a stronger influence on the steering than it would have, acting on A . Therefore I reject Q and I certainly reject P. Apparently there is more between heaven and earth, as a former owner of my car has perforated the brackets at P and Q and not at A. I ask this Forum: What on earth can have been his arguments to do so?