Callaway's Big Bertha Fusion goes all in on forgiveness

In an era where designing drivers has trended more often than not toward oodles of adjustable features and settings, Callaway’s latest driver, the Big Bertha Fusion, remembers that for the vast majority of golfers forgiveness is what matters most.

Yet to get there its team of engineers had to employ the most complex set of materials technologies and design shaping they’ve ever employed.

The Big Bertha Fusion sets new company standards for expanding the area of the face that provides the highest ballspeeds, while also enhancing another kind of forgiveness, namely the ability to more easily deliver the clubhead to the ball at increased speed.

The Big Bertha Fusion driver incorporates two kinds of carbon composite material in the crown and two additional pads of carbon composite in the sole. The carbon pieces join an exo-skeleton like body frame made of lightweight titanium that includes the sole and skirt sections. The carbon composite includes a piece of Callaway’s chopped fiber forged composite material at the front of the crown that’s more than a third thinner than previous versions. That’s then fused to a section of Callaway’s newly developed woven triaxial carbon material that’s 65 percent lighter than titanium.

The new materials allow the Big Bertha Fusion to improve moment of inertia numbers in both the heel/toe (or open/close) direction and the up/down (or loft/de-loft) direction. Moment of inertia is the degree a clubhead stays stable or resists twisting on off-center hits, leading to less lost ballspeed. That means your mishits lose less distance.

According to Callaway, which began using carbon composite materials in drivers 15 years ago, the new materials freed up 35.4 grams to be redistributed in the head for an overall MOI (combined in the heel-toe direction and up-down direction) north of 8,500 grams/centimeters squared.

“With these products we really wanted to leverage our expertise in this area,” said Evan Gibbs, Callaway’s director of metalwoods research and development.

While the MOI in the heel-toe direction has improved to above 5,000 grams-centimeters squared (the USGA limit is 5,900 and only in this direction), it’s the improvement in the up-down stability that might be even more intriguing.

“With a driver face being a lot wider than it is deep, the ballspeed dropoff as you mishit the face vertically drops off a lot quicker,” Gibbs said. “So maintaining a high moment of inertia in that axis is critical.”

What’s no less important is that while engineers pushed the MOI higher by moving the center of gravity farther away from the face, the use of the lightweight materials in the crown also helped keep the center of gravity low.

“The idea that we’ve been able to reduce the CG height this much and protect it with this much MOI is a big deal,” said Alan Hocknell, Callaway’s senior vice president of research and development.

The head features Callaway’s step pattern on the crown, developed in conjunction with engineers at Boeing, as well as a slightly triangular shape, both to improve clubhead aerodynamics. Typically, drivers designed with aerodynamic efficiencies give up a little stability due to their streamlined size, but according to Callaway, the Big Bertha Fusion’s overall MOI is 17 percent higher than this year’s XR16 driver. Gibbs said it brings back some of the MOI strengths of Callaway’s FT-iZ, which he called “the king of the robot testing until this driver,” with the lightweight, aerodynamic aspects of a driver like the Big Bertha V-Series.

The club features Callaway’s eight-way adjustable hosel that lets the user change loft independent of draw and neutral face angle settings. In addition and unlike any other current driver on the market, its stock version will be available in two lengths. There will be a 45.5-inch version and a 44.5-inch version. Gibbs said the ideal for each golfer is not necessarily obvious.

“The averages show us one thing, but I think it’s more important to look at it from an individual basis,” he said, noting that in one of Callaway’s tests 20 percent of the players hit the shorter version farther.

“It definitely can have an impact on head delivery, both impact location, path angle and attack angle.”

The Big Bertha Fusion line also will include fairway woods that feature the triaxial carbon weave material in the crown. Weighing just 5.8 grams, Callaway engineers say the crown on these fairway woods is some 78 percent lighter than a typical stainless steel fairway wood crown, allowing for improved stability and CG location. The fairway woods also feature Callaway’s wraparound cup face technology to improve the way the face flexes.

Both the driver and fairway woods can be ordered starting Sept. 9 and will be in stores Sept. 30. The driver is available in 9-, 10.5- and 13.5-degree lofts, while the fairway woods come in 3-, 5- and 7-wood lofts.