26-06-2018, 10:35 AM
While on the topic, those who have driven Morris Minors, A35s, Starlets etc with 7 inch brakes may wonder why the Seven brakes are so less effective. With hydraulic 200 psi in the pipe applies to all cylinder pistons, whereas say 400 lb in tension is divided between the cams. There is also notable friction. A hydraulic or true Girlig leading shoe, if drawn by braking action into heavier contact, retains the applied pressure as follow up. With the Seven the cam cannot follow as it is restrained by the other much less effective trailing shoe. The self acting effect with others is normally a source of fade, but this is academic if feeble anyway. I dunno if anyone has tried with a bare trail shoe!
Most moderns have the shoes free to move endways. You would expect this to cause grab, dragging etc but hundreds of millions cannot be wrong. Some have achieved this with Sevens but most systems are not very workmanlike.
Most moderns have the shoes free to move endways. You would expect this to cause grab, dragging etc but hundreds of millions cannot be wrong. Some have achieved this with Sevens but most systems are not very workmanlike.