The Tour began voluntary testing of the coefficient of
restitution (a.k.a. the springlike effect) of drivers at the
Mercedes Championships. Matt Pringle, the USGA's senior research
engineer, has spent three years developing the pendulum tester
and helped administer the tests at Kapalua.
This is an article from the Jan. 19, 2004 issue
SI: Your machine is a steel ball swinging down on the clubhead?
MP: Yes. It's an extremely simple concept. When a mass collides
with a spring, the duration of the collision depends on how
flexible the spring is. For a flexible club, the contact lasts
longer than it does with a rigid club.
SI: Have many players asked how this test works?
MP: No. Press inquiries have far outnumbered the players'. That's
half of the reason I'm here.
SI: How many clubs have you tested in three years?
MP: More than 1,000.
SI: How many didn't conform?
MP: A lot. There are two markets for clubs--the U.S. has limits
and, until recently, the R&A didn't. So a lot of nonconforming
clubs were made for Europe and Japan.
SI: How many players had their drivers tested last week, and were
MP: You'd have to ask the Tour. This is like a doctor-patient
relationship--the results are between the Tour and the players.
But I'd be surprised if any clubs on Tour weren't hand-selected
and pretested by their manufacturers.
SI: Do you think we'll see driving distance drop this year?
MP: The only thing I hope testing accomplishes is that there'll
be no more suspicion in anyone's mind, and I think it will.
SI: After the initial stress of worrying that somebody might be
disqualified for having an illegal club, was it a fun week at
MP: Absolutely. Any time here is better than hanging around the
office. I'm not going to lie to you, this has been great for my
SI: Did you also invent Pringles potato chips?
MP: No, but I wish I had.
SI: Compared to Pringles, are normal chips nonconforming?
MP: Yeah. Get some uniformity.