SA Police had the square fours in the old days as well. That was prior to having the BSA 650's that were still in service when I joined. An old mechanic that worked on them told me that the Arials were just rubbish. On a fast run the rear two cylinder would overheat and seize, stopping the bike. The local rascals, including my wife's uncle, new it. They would induce a chase with a high speed pass, sit at speed until the police bike stopped, and then do a "U" turn and go back to give the coppers some stick on the way past.
