New York (AFP) - A New York police detective and another man were found guilty Tuesday over a road rage chase that ended with a banker beaten in front of his wife and toddler in broad daylight.

Judge Maxwell Wiley found detective Wojciech Braszczok, 34, guilty of second-degree assault, criminal mischief, coercion and riot over the September 29, 2013 incident in Manhattan that shocked New Yorkers.

New York police promptly suspended the detective pending termination.

Braszczok, who was off-duty at the time, was acquitted on two more serious assault charges, local media reported.

Robert Sims, 36, was convicted of attempted gang assault, attempted assault in the first degree, assault in the second degree, coercion, criminal possession of a weapon and riot.

The two men will be sentenced on August 5 and 6. Braszczok faces a maximum sentence of seven years, and Sims between five and 15 years.

Nine other bikers involved in the episode have already been convicted of second-degree assault for their roles in the attack.

Banker Alexian Lien, 33, the driver of a luxury Range Rover, was brutally assaulted after a gang of motorcyclists chased him down following a brief confrontation with one of the bikers.

To get away, Lien ran over and injured one of the motorcyclists.

His wife, Rosalyn Ng, and two-year-old daughter were in the car at the time. Ng said her husband acted because they faced "a life-threatening situation" from "a mob of reckless and violent motorcyclists."

"Within a matter of minutes this group of bikers began a ferocious and unrelenting assault on the victim, alarmingly close to his wife and young daughter," said Manhattan district attorney Cyrus Vance.

When the bikers caught up with Lien's SUV, one of them bashed the driver's window with his helmet until the glass shattered, allowing other defendants to strike Lien through the broken window.

He was dragged out of the vehicle and thrown to the ground, where prosecutors said he was kicked and beaten to the point of unconsciousness.

Braszczok knocked out the rear window of the SUV, showering Lien's wife and daughter with broken glass. He then kicked the rear door and window area of the vehicle, prosecutors said.

Lien was admitted to hospital following the attack.