The OED gives this quote 1970 Cycle World Oct 34 Suzuki s entry in the Superbike field just happens to be an excellent touring bike Over at google books the term pops up all over the place after between 69 and 71 Here and here are examples of sources saying the era of the superbike began with the CB750 four It would be nice to find out exactly which magazine first use the term applied to a motorcycle it seems to have been commonplace by 1970 The Kawasaki Mach III was introduced a month earlier than the CB750 and could have but wasn t apparently for whatever reason called the first superbike The Triumph Trident and BSA Rocket III also went on sale before the CB750 Yet the British machines for all their performance and good sales are seen now as the last gasp of a dying industry seeming to be a 1937 era Triumph twin with another cylinder grafted on while the Honda was at the vanguard of a new era that has remained with us to this day It wasn t that the CB750 was the fastest ever or the first four or even the first transverse four but that it was practical reliable cheap and could be delivered to the public on a massive scale The disc brakes were a production bike first See Classic Japanese Motorcycle Guide pages 76 79