Prosecutors say an off-duty police detective was among the bikers who pursued and beat Alexian Lien after a confrontation on the West Side Highway.
The September assault was recorded by one biker and later posted on the Internet.
The New York Post reports (http://bit.ly/1dEaPhQ) that Lien filed a formal "notice of claim" against the city on Dec. 24. It accuses the police department of failing to properly train officers.
A spokeswoman for the city's Legal Department said it would defend the claim if it proceeds to a full lawsuit.
Information from: New York Post, http://www.nypost.com