What my senile old brain can remember from my bike shop days was that Centurions were road bikes advertised as a triathelete's bike while Diamonbacks were mostly mountain bikes. I do recall the transition as the Centurions changed their decals to Diamondback. Both were imported by Western States. However, I don't know if that Centurion was made by the same company that made the Cinelli lookalikes. I have seen several older Centurions and they were real clunkers with cheapo components and I never associated them with the nicer triathelete type bikes. I could be wrong, but I believe the headbadge was different. This was also about the same time frame that the Nishiki Olympic became a hot seller.
Fred Durrette
Summerville, SC