06-03-2019, 07:42 AM
While we are all splitting hairs, the cam is most efffective just before it wedges open. A large angular movement then produces very small shoe movement so the leverage is great. But normally at that position the lever is at an inefficient angle which counters. (It is vital cams cannot reach the locked state. After braking all wheels release except the locked one and the result can be exciting. I have seen many primitive shimming arrangements which, if failed, would risk locking