John, I don't know why but I would guess that from 84 onwards clipless pedals became the norm and concealed cables as well. Nothing was the same in the Pro Peleton after 83 Look launched their clipless pedals in 84. Cinelli did it years earlier but these were mostly used on the track.
Thats all for now. Keep those wheels spinning, in your memories if not still on the road. Be lucky Mick Butler Huntingdon UK.