"List of Norton motorcycles"@en . . . . "Norton Commando models used Isolastic suspension and had 745 cc (\"750\") engines up to 1973 when the 828 cc (\"850\") engine came into use."@en . . . . "Norton Commando models used Isolastic suspension and had 745 cc (\"750\") engines up to 1973 when the 828 cc (\"850\") engine came into use."@en .