Sumo2 drivers recalled for 'conformance issue'

Nike Golf will recall its new, square-shaped Nike Sumo2 driver due to what it calls an "unauthorized manufacturing variance." According to sources, Nike is instructing retailers to remove the driver from shelves "immediately" and begin returning them to the company. Individual golfers will be able to return their current Sumo2 driver for a new, conforming model starting March 26.

In a memorandum sent to Nike's golf professionals and retailers, company president Bob Wood said, "The CT of a number of drivers fell out of our approved engineering specifications. While the result of this variance is an additional distance benefit of only one to two yards, it lies outside of the parameters as established by the USGA."

Wood said the problem was brought to his attention by the USGA in late February, and that the USGA was made aware of the potential problem by a "competitor."

Characteristic time (CT), which is measured by the so-called "Pendulum test," refers to a driver face's tendency to deform slightly at impact, resulting in improved ball speed. The USGA and R&A set a characteristic time limit of 239 microseconds, plus a tolerance of 18 microseconds. This correlates to the previous coefficient of restitution (COR) test and its limit of .822 with a manufacturing tolerance that extended to .830. By comparison, a wooden-headed driver has a COR of about .780.

"I don't think anybody can sell a driver made at 239 [CT]," Wood said in a conference call with reporters. "I'd be pulling your leg if I didn't say that we didn't try to get as close as possible to the limit."

In the memorandum to retailers, Wood said, "As it stands today, the USGA doesn't have a published protocol for the ongoing testing of compliant product once in the marketplace. Therefore, Nike Golf is voluntarily conducting a testing and replacement program with the USGA to potentially serve as one model for the industry. We intend to do this in an open and straightforward manner. We expect other manufacturers' products to be tested in the future." The implication being that the USGA should further examine all manufacturers drivers as perhaps there are other clubs in a similar situation.

Conforming versions will be shipped within a month and will have a circular notch on the soleplate indicating they are USGA conforming. In addition, Nike will provide, via its Web site or by calling 866-632-6453, the opportunity to trade in their current Sumo2 driver for the new version starting March 26 and running through April 30. Wood would not reveal how many Sumo2 drivers have been sold, nor would he give an estimate on how much the exchange program would cost Nike.

The Sumo2 driver has been used by several PGA Tour players, including K.J. Choi, who won the Chrysler Championship in October with the club in his bag. Wood said all drivers used by Nike's tour staff have been tested and conform to the Rules of Golf.

The Sumo2 is on the USGA's current conforming list, and Wood said a new version of the club has been submitted to the USGA and is expected to be on the USGA's new conforming list when it is published Monday.