Trampoline effect (heretofore known as spring-like effect) entered golf’s lexicon in 1998, creating an enduring controversy. In 1999, Golf Digest developed its own titanium driver that failed the USGA’s conformance test. The nonconforming driver generated on average 2 percent more ball speed than the conforming club, translating to one or two yards on 220-yard shots but escalating to four to six yards on 270-yard shots. The greater the swing speed, the greater the increase in ball speed and carry distance.
A caveat: The advantage occurred only when the ball was struck on an exact impact location.
These balls are hot
You see them advertised, “hot balls” that do not conform to USGA regulations (and aren’t allowed in tournament play governed by USGA rules). Is it hype or is it real? Our robotic testing earlier this year showed these so-called hot balls average five to 15 yards longer off the driver than a conforming distance-type ball. Most of the difference was generated in carry. The balls, incidentally, are smaller and heavier than conforming balls.
Does size matter?
In 1991, oversize drivers–Callaway Golf’s Big Bertha and Yonex’ A.D.X. among them–transformed the equipment industry. Is bigger really better, we asked? To find out, we tested the Big Bertha against a previous Callaway entry, the S2H2. Note the lower center of gravity (red dot) on the Big Bertha.
The Big Bertha produced a greater average carry, whether the clubhead speed was 85, 95 or 108 miles per hour, on center hits, high toe hits or low heel hits, with a two-piece ball or a three-piece wound balata. In each case, the difference in average carry was greater on off-center hits than center hits, proving, at least, that oversize drivers are more forgiving.
Tests of time
How do today’s balls and clubs compare with those of yesteryear? We asked the question in 1994 and pitted a Wilson Staff Dynapower 5-iron from 1973 against a Wilson Staff Ultra 45 5-iron from 1993, a ’73 model Wilson Staff 11 driver versus a Wilson Killer Whale, and a 1970-model Titleist K-2 Acushnet ball against a ’93 Titleist Tour Balata. The overall conclusions: The new equipment outperformed the old equipment, but to a lesser degree than some claimed. Also, the old ball hit with the old clubs went as far as the new balls hit with the new clubs.
It was a given that big hitters required stiffer shafts than short hitters, a notion we set out to prove–or disprove in 1994. For our test, we employed 19 golfers–men and women, high handicappers and low handicappers, hard swingers and easy swingers–and had them swing four drivers, each with a different flex: L (weakest flex), R (medium), S (stiff), and X (extra stiff). The results were not what you might have expected. For instance, a longer hitter does not necessarily bend the shaft more during the swing than a short hitter. Acceleration, not final clubhead speed, may be the key to choosing your shaft flex.
Steel or graphite?
We tested identical 5-irons, one equipped with a steel shaft, one with a graphite shaft, in 1998. The graphite-shafted 5-iron hit the ball farther by about five yards, probably due to its lighter weight, resulting in greater swing speed. The steel-shafted 5-iron, meanwhile, maintained more consistent distance control. The steel-shafted iron averaged 50 percent less variation in distance and dispersion.
The right driver for your game
We deployed robotic and real golfers for the third time in 1999 to analyze the industry’s best-selling drivers for shot shape and trajectory tendencies. The purpose of the test was to cut through the marketplace clutter and help steer you toward a driver more suitable to your game.
Of our test group, some drivers performed differently when swung by the robot than when swung by players. One driver, for instance, produced a slight draw when hit by a robot, but delivered a fade when hit by a golfer. We also found that drivers might look similar and cost virtually the same, but the differences can be both subtle and immense. The test confirmed the old adage: Try before you buy.