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Golf ball speed limits
Golf Tips by Don Burleson
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Anyone who has used a wooden
driver from the 1950's knows that golf has undergone a huge
technical revolution, better titanium clubs and soft, long
balls, making super-long drives easier than ever before.
This technology has added at least 50 yards to the drive of the
average golfer, and the golf technology now threatens US golf
courses, who cannot afford to extend hole lengths to accommodate
the changing technology.
It's all about real estate and
keeping the golf courses "long" enough. Golf course real
estate is more expensive than ever before, and the USGA has
stepped-in to impose performance limits on approved golf
equipment.
Lets tale a closer look at how the
USGA limits golf technology.
Limits on Golf ball performance
Its hard to believe, but the
USGA imposes a speed limit" for golf balls!
This USGA article
shows the dynamics of the speed of a golf ball, showing the basic correlation
between club head speed and distance. There is a movement to "slow-down"
the ball distances, but only for the best golfers:
Now, if it was true that
these new, high-tech balls and drivers were benefiting the longer hitters
the most, we would obviously expect to see that they had the biggest
distance increase. However, as the chart clearly shows, this just wasn't
true.
Measuring golf ball speed
Golf ball coefficient
of restitution (COR) is used to express golf ball speed limits and the COR
is defined as:
A measurement of the
clubface's ability to rebound the ball, expressed as a percentage that is
determined by a ball's speed off the club head divided by the speed at which
it struck the club head.
The term [coefficient of
restitution] came into the popular lexicon as ultra-thin-faced drivers began
to proliferate. An effect of the thin faces is known as the "spring-like
effect" or "trampoline effect":
The face of the driver
depresses as the ball is struck, then rebounds - providing a little extra
oomph to the shot. A driver that exhibits this property will have a very
high COR.
Illegal golf balls
There are many golf balls
that exceed the USGA specification and are "illegal for tournament play".
These illegal golf balls have names like Bandit and Desperado, all technically
illegal golf balls because they will fly too far. Remember the Whamo
Superballs from the 1960s?
"Illegal" golf balls exceed USGA speed
limits
This article
notes the USGA speed limits for golf balls:
Although a speed limit
on golf clubs is a recent action (see December 1999), limits on golf-ball
performance have existed since the U.S. Golf Association set a distance
standard in 1976-280 yards plus a 6-percent tolerance.
The USGA also limits a
ball's size, weight and initial velocity.
There is also a movement for
a "miracle"
golf ball that would allow beginners to have a long drive while limiting the
distance for PGA professionals:
The reactionaries'
solution is to advocate what's being called "the miracle ball." It's the
hypothetical golf ball that would limit Tiger to 290-yard drives, but at
lesser swing speeds (ours, for example) results in no or little loss of
distance.
Golf ball feedback
Today's gold balls are "soft", and
designed to compress easily, providing for the "spring" that
gives longer distance:
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| Addressing the ball |
Simulation of strike compression |
My Callaway Fti Driver has a huge
sweet spot (perfect for a beginner like me), but best of all, it
keeps a dimple imprint, showing the amount of ball compression
after my swing. Below, we see the clear evidence of the
golf ball impression with about a 90 MPH club head speed (225
yard drive):
Testing the long balls
I purchased a box of "illegal" golf balls and went to
Brad Clayton, an amazing PGA pro with a consistent swing that could
be used to test the coefficient of reciprocity for these illegal balls.
Brad did a one-armed swing with both legal and illegal balls.
For the best golf instruction in North Carolina, we
recommend The Golf Zone. PGA Master
pro Brad Clayton is one of the best golf instructors on the eastern seaboard.
