I worked for a bike shop in the middle 80's after a departure from 1979 to 1984.
Things I saw, not quite in order:
126mm was the width, 120 was passe.
Araya aero section clincher rims were popular for training, strong, no polishing required, and Specialized Trubos or Turbo S's were the training tire.
Bennetto bar tape or the new Cinelli padded stuff.
"Miami Vice" paint, somebody forgot how to set up a spray gun and "splatter" paint was in. The unhappy accident.
The Turbo saddle
The Trubo model bike
The Trubo trainer.
Rreliance on "turbo"
The acceptance of Shimano by racers. "SIS" aka "Sissy shifting"
The arrogance of Campagnolo (unfortunate)
Mountain bikes outsold road bikes.
Attractive Women discover cycling as exercise, that was a good thing.
Investment cast lugs are the common denominator.
Chrome on the chainstay
Under the chainstay shift cable routing
The braze on front derailleur.
Love of braze ons.
Double water bottle mounts.
Clement had competition, Vittoria.
Look pedals arrive. Shoes are behind the curve for a while and rip apart.
The acceptance of the Fit Kit.
The introduction and withdrawal of Campagnolo Delta brakes.
The end of the Suntour slant parallelogram patent.
8 speeds are needed in racing.
Quit the bike shop before the end of the decade, they just would not pay enough.
One could make more and have a more flexible schedule in fast food.
And had collected enough attractive women who needed bikes maintained to keep me happy.