Nike to replace some Sumo Squared drivers
Nike said none of its PGA Tour staff was using the square-shaped driver that exceeded a measurement called "characteristic time" because their clubs are handled at a different facility.
Tiger Woods has never used that model in competition.
Nike president Bob Wood said the USGA notified the company in February there might be a problem. He said Nike conducted its own investigation and found that during production of the drivers for consumers in the United States, Canada and Europe, a variance occurred that made the club fall narrowly outside the specifications.
Characteristic Time (CT) measures in microseconds how long the ball stays on the club during impact. The USGA created the test to measure the trampoline effect in drivers, and the PGA Tour has adopted it for competition. Starting in 2004, the tour allowed players to voluntarily have their drivers tested to make sure they conform, but only a small number did.
Wood said a competitor told the USGA of potential problems with the Nike club, but he did not identify the company.
He said consumers had between March 26 and April 30 to ask for a replacement driver. He declined to say how many Sumo Squared drivers the company had shipped to retailers.