Driver Designs

First wooden driver head >250cc in volume/size / 1994 - Golfsmith Long Jon Laminated Maple + Graphite Insert Driver

In the early 1990s, the trend had already begun to design larger size driver heads. As a form of driver head size comparison, the golf industry began to reference the volume of the head in cubic centimeters (ss) of volume. In the early 90s, stainless steel woodheads were the established norm as titanium had not yet been used as a woodhead material. However, the clubhead production foundries had not yet achieved the skill to cast very thin wall sections so it was not possible at this time to make stainless woods any larger than 200cc.

In the early 1990s there was still a reasonable demand for wooden drivers. Prior to the Long Jon, the largest wooden driver head was 200cc in volume. To make a larger size wooden driver, Tom chose laminated maple for the woodhead material because it was stronger than persimmon. After performing extensive R&D to determine the maximum possible size of a cavity inside the wooden head to reduce weight, and through using a very light polymer over the full face width face to further reduce headweight, the Long Jon driver was able to be designed to a significantly larger wood head size at just over 250cc in volume.

First driver family designed with specifications matched to different golfer swing speeds / 1995 - Golfsmith Designated Drivers

In the mid-1990s, Tom began to educate clubmakers of the importance of matching driver loft to the golfer’s clubhead speed. Key to this information was the realization that the slower the golfer’s clubhead speed, the higher the driver loft needed to be to maximize the carry distance of the shot. Prior to this information, clubmakers and golfers had always assumed that the lower the loft, the greater the distance generated by the driver.

Wishon’s Designated Driver series in 1995 consisted of 5 different stainless steel driver heads, each designed with a different loft, face height and face angle that was matched to 10mph increments of golfer clubhead swing speed from <70mph up to >100mph. By engraving the different clubhead speed on the sole of each driver head, golfers had a much better chance of being fit with a driver that was properly matched to their swing speed to achieve the most distance possible for their speed.

<strong>First graphite + metal hollow cavity driver head</strong> / 1995 - Golfsmith Power Link Driver

Golfers may recall the 2004 Callaway Fusion driver and believe its metal + graphite hollow body design was the first time a company had created a hollow body, composite and metal driver head. However, the first such metal + graphite hollow body driver head design was designed by Tom Wishon in 1995. Tom had always been intrigued by the possibility of combining two materials of totally different density, heavy and light, in the same clubhead for the purpose of improving weight distribution and center of gravity (CG) location.

The Power Link represented a pioneering design in both weight distribution and in the new manufacturing techniques required to enable such a design to be produced. The Power Link’s investment cast stainless steel face, sole and hosel piece was placed into a compression mold with a special inert core so that graphite could be molded to the steel face/sole piece to create the complete shape of the hollow driver head. This enabled the Power Link driver to have a high portion of the head’s weight positioned in the sole and face to keep the CG low and more forward. Of particular difficulty in the design was having to achieve a high level of repeatable precision in the cast stainless part to enable each cast piece to properly fit in the compression mold the same exact way every time. An additional challenge in this breakthrough design was to determine how to engineer the fit and the durability of the graphite shell to perfectly fit to the edges of the steel all around the face and sole edges.

First heel weighted draw bias metal wood driver for fade reduction or draw enhancement / 1996 - Golfsmith AccuCore Driver

The concept of heel weighting in clubheads to assist golfers to reduce the tendency to fade the ball was first suggested in 1968 in Alastair Cochran and John Stobbs’ milestone book, The Search for the Perfect Swing. Working in conjunction with the late Elmore Just’s Louisville Golf Company in 1991, Tom and Elmore designed a heel weighted wooden driver to test Cochran & Stobbs’ theory. But the problem with creating a heel weighted design in a wooden head was that the relatively high density of the laminated maple or persimmon did not allow more than 10-15 grams of weight to be positioned in the heel. This amount of heel weighting proved to be minimal in its ability to reduce a fade or enhance a draw.

To be able to create a visible change in the flight of the ball, Tom felt the heel positioned weight had to be in excess of 25 grams, yet because of assembly requirements the total driver head weight had to be no more than 200 grams. In the early 90s, no clubhead foundry possessed the manufacturing skills to achieve this in a steel or titanium body driver head. To be able to make a 200 gram driver head with a durable wall structure and with more than 25 grams of discretionary weight to put into the heel area of the head, Tom knew the head body material of such a driver had to be a high strength aluminum alloy.

The first AccuCore driver prototypes made in 1994 with a 25 gram brass heel weight showed only a very small draw bias flight tendency for the shot. Successive prototypes were made to further thin the walls of the 7075-T6 aluminum alloy head so more weight could be put into the heel. Finally with the heel weight at 43 grams, testing showed a distinct draw bias shape for shots hit with the driver. The AccuCore metal driver was introduced for sale in 1995 and represented the golf industry’s first metal wood with draw bias weighting. The first such driver offered by a major brand golf company came out several years later.

First stainless steel driver head to exceed 225cc volume / 1996 - Golfsmith SS-235 Driver

When Titanium woodheads were introduced in the US in 1994, the lower density and high strength to weight ratio of Titanium opened the door for clubhead designers to meet the public’s increasing demand for ever-larger driver head shapes. However, Titanium drivers were significantly more expensive than what the majority of golfers in the US were yet willing to pay. This meant there was a also a demand for larger stainless steel drivers. However, the largest stainless steel driver up to 1995 was only a little more than 200cc in volume/size because clubhead casting foundries had not yet developed the ability to consistently cast stainless steel in thinner wall sections to allow the head size to be increased.

The SS-235 driver was a 235cc volume/size driver head investment cast from 17-4 stainless steel which employed changes in the ceramic shell formation of the casting process followed by a different heat treatment process of the cast head to allow the SS-235 to have a thinner wall construction which still was strong enough to withstand the wear and tear of normal use. This increase in volume/size pushed the envelope in stainless steel driver head manufacture to a size and a level of casting expertise not seen before in the golf industry.

First metal woodhead to exceed 350cc volume / 1997 - Golfsmith Long Jon jumbo metal driver

Today, a 350cc metal wood driver is considered to be a small size head. In 1997, titanium driver heads were just beginning to approach the 300cc barrier in head volume/size because the skill required to consistently cast titanium alloys into very thin wall sections did not exist among the clubhead production foundries.

Again turning to high strength aluminum alloys for the solution, Tom designed the Long Jon metal wood driver to be forged from aircraft grade 7075-T6 aluminum. Through the forging process, it was possible to achieve the required material strength in the thin wall sections that were required to be able to manufacture a 350cc volume/size driver head at the required head weight with the necessary head durability. At the time of its introduction in 1997, the Long Jon was over 50cc larger than any metal driver head yet made.

First metal wood with stainless steel body + aluminum hosel / 1997 - Golfsmith Bi-Metallic woods

A clubhead designer can look at the weight comprised in the hosel of a clubhead in two ways –it could be mass that can be used to assist in reducing a fade or accentuating a draw by helping to move the CG closer to the heel side of the clubhead, or it could be mass that can be eliminated or reduced in some manner and re-distributed in the head to improve perimeter weighting (MOI) or to customize the center of gravity (CG) location.

Following the latter design concept, the Bi-Metallic woods were a full set of driver and fairway woods in which Wishon designed the body of the woodheads from 17-4 stainless steel and the hosel from high strength 7075-T6 aluminum. By creating the hosel from such a light weight material, more weight was able to be moved into the sides of the woodheads to increase the MOI of the heads and offer better off center hit performance than was possible with stainless steel woods made with a conventional stainless steel hosel. In addition, because the hosel was made from aluminum, vibration from the head up to the golfer’s hands was also able to be reduced.

First metal wood with titanium cup-face construction / 1997 - Golfsmith BlackHawk Driver

Even before Tom began to assign finite element analysis to predict the performance of a metal wood face design, he was aware that the strength to modulus ratio of Titanium made it a better face material for increasing ball velocity. Tom also realized that the spring face capability of a Titanium face would be enhanced by increasing the surface area of the face that could be unsupported or untouched by welding. Driver heads in which the face was welded to the head body on the edges of the face experience a reduction in the total area of the face that could flex inward at impact.

By first forging a 6/4 Titanium face in a cup-face construction and then casting high strength 7005-T6 aluminum material of the body of the Black Hawk Driver around the ‘cupped’ edges of the Titanium face, the deflection (spring face) capability of the face for its designed size was able to be maximized. The same ‘cup-face’ Titanium face construction as employed by Callaway Golf in their Titanium woodheads, did not come about until 2 years later.

First beta grade titanium alloy driver introduced in the USA / 1998 - Golfsmith Beta Titanium 255LT Driver

Alloys of beta grade Titanium offer an increase in strength over typical 6/4 Titanium. Even when combined with the higher modulus of beta Ti alloys, their strength to modulus ratio is such that a driver could be made larger in size than when made from 6/4 Ti alloy. In addition, the properties of a beta Ti alloy can offer the chance to create a driver with a higher C.O.R. than what is possible using the 6/4 Ti alloy that had been so predominant in titanium driver design up to this time.

While the golf market had become accustomed to the higher price of a 6/4 Titanium driver over their stainless steel predecessors by this time, the higher raw material cost of the more sophisticated Beta grade titanium alloys would raise the price of a driver even higher. Therefore, in the late 1990s, all of the US golf companies were hesitant about switching from 6/4 Titanium to a beta grade Titanium for their driver designs. Because Tom was relying on computer modeling at this time to predict the performance of a driver face design, he knew the potential for both increasing head size and improving the COR of the driver face design that the beta grade titanium alloys offered. Thus, in 1998 the model 255LT beta Titanium driver was not only a larger size Titanium driver than what had been offered before, but also increased the COR over what had been done before, and became the first driver made fully from a beta titanium alloy commercially offered in the US.

First Driver with maraging steel alloy face to exceed 300cc in volume / 1998 - Golfsmith Super Sonic Boom Driver

Maraging steel is a classification given to certain alloys of steel which typically possess strength up to and more than twice that of common stainless steel alloys such as 15-5 and 17-4. By the late 1990s, maraging steel alloys had only been used as a face plate attached to a stainless steel body and never designed to be larger than 240cc in size/volume. By attaching the maraging face to a 300cc forged high strength aluminum body, the Super Sonic Boom Driver not only became the largest steel face Driver in the golf industry, but the maraging steel face eliminated the less popular low-pitched “thud” sound of an all aluminum woodhead. The result was a high performance ultra-thin face construction that not only increased the COR but rendered a more favorable sound at impact.

First boron carbide metal matrix investment cast clubhead / 1998 - Golfsmith Cermet 2000 Driver

Aluminum metal matrix composite (MMC) materials have to be thought of as almost being ‘aluminum on steroids’. On its own, the highest strength aluminum alloys can rarely exceed 100,000 psi in strength (6/4 Ti and 17-4 stainless steel are 140,000 psi, 10-2-3 Beta Ti is 185,000 psi and Carpenter 455 steel is 250,000 psi to contrast). However, by adding a ceramic material the strength of the resulting MMC can be significantly increased, to the point that some MMC’s will approach and even exceed the strength of some stainless steel alloys.

As a material for potential use in clubhead manufacture, MMCs held the potential for a high strength to weight ratio so a larger head size could be designed with additional weight still available to be positioned in specific areas of the head to enhance perimeter weighting (MOI) or customize the head’s center of gravity (CG) location.

In the mid-1990s a company named Langert Golf had introduced a small size driver head made from Aluminum ‘alloyed’ with a ceramic called Silicon Carbide (SiC). The head was produced through an expensive die casting procedure that was required to keep the distribution of the SiC particulate consistent through the aluminum and thus achieve consistent strength equally in all areas of the head. SiC MMCs are known to be very brittle. The Cermet 2000 Driver was innovative because previously, no MMC Driver head had yet been produced by the less expensive procedure of investment casting.

In addition, the MMC used in the casting of the Cermet 2000 Driver head incorporated the use of Boron Carbide (B4C) ceramic particles. Using B4C ceramic material in the aluminum alloy allowed the strength of the MMC to be higher than an MMC made with SiC ceramic particles. Through investment casting, the tooling costs and the per head cost could be greatly reduced, while the use of B4C increased the MMC strength while making the MMC less brittle. This allowed the Cermet 2000 to be made in a larger head size and in different model options for a price that was far less expensive than a Titanium driver head. Later the Cermet heads originated by Tom Wishon expanded their performance potential with the addition of bi-material weighting in the head body to further improve on their perimeter weighting (MOI) capability.

First Metal Wood to vary face thickness to match different clubhead speeds / 1999 - Snake Eyes Elasteel driver and 3 wood

From basic computer modeling studies of wood face design, Tom noted that the maximum ball speed and highest “smash factor” (ball velocity divided by clubhead speed) occurred when the face was flexed inward to its maximum point before permanent deformation. At the same time, computer modeling revealed that the amount the face could flex inward was proportional to the clubhead speed of the golfer. That meant golfers with slower swing speeds who were buying titanium drivers with faces designed to flex fully only for the highest swing speeds of golfers were not getting the maximum ball velocity and smash factor from their purchase.

Tom designed each of the three Snake Eyes Elasteel drivers and 3-woods with a different face thickness to achieve its maximum face deflection for a different range of golfer swing speeds. Thus the golfer with a 75-90mph swing speed used an Elasteel driver with a 2.25mm thickness face, a golfer with a 90-105mph swing used the Elasteel driver with a 2.6mm face, and golfers with a >105mph swing speed used the Elasteel driver with a 2.9mm thickness face. As a result all three ranges of swing speed players were able to gain a similar amount of face deflection and ball velocity performance increase. Such a design concept required a communication campaign to prevent high swing speed golfers from using the Elasteel driver and 3-wood designed only for the lower swing speeds! Fortunately, people listened as only four Elasteel drivers were returned with broken faces from being used by a player with a higher swing speed than what the head was designed to withstand!

First USGA C.O.R. non-conforming driver with steel alloy face construction / 2000 - Snake Eyes AerMet CMF Drivers

In 1998, the USGA enacted a limit of 0.830 for the Coefficient of Restitution (COR) of Drivers. Not until 2008 did the Royal & Ancient of St. Andrews enact this same rule. As a result, golf companies with the capability of designing high COR driver heads would create two versions, one with a COR of less than 0.830 for use by golfers in countries that played the game under the USGA rules (USA & Mexico), and one with a higher COR for use by golfers in all other countries legislated by the rules of the R&A. Because they wanted to keep track of all “USGA non-conforming” high COR drivers to prevent them from showing up in competitions in the US and Mexico, in 1999 the USGA began to publish a list of all of the drivers in excess of the 0.830 COR limit.

Until the design of the Snake Eyes AerMet CMF drivers, every driver on the USGA’s COR non-conforming list was a titanium alloy driver. No golf company had developed a steel driver with a COR over the USGA’s limit because it was felt in the industry that the strength to elasticity properties of steel could never allow that to be done. Working with Carpenter Specialty Metals company, Tom identified their AerMet high strength steel alloy as potentially suitable to be able to design a 300cc size all steel driver with a COR in excess of the USGA limit. (The USGA tested COR of the Snake Eyes AerMet CMF drivers was 0.854)

First metal wood with cup-face construction forged from high strength steel / 2000 - Golfsmith TI Steel 465

Prior to 2000, all woodheads using a high strength steel alloy for the face had been made by either press-fitting the face piece into an open cavity on the face surface, or welding the face piece on the outer edges around the face of the wood. Such attachment methods of the face to the body of the head reduced the area of the face that was able to be flexed inward and with it, reduced the potential for a high strength steel face to offer the same ball velocity as a titanium alloy face.

During this time, Tom Wishon had been working with a number of manufacturers of high strength steel alloys and studying computer face modeling of their various alloys that possessed strength properties in the range of 250,000psi and higher. With such ultra-high strength alloys, he had determined it was possible to create steel face drivers that could offer the same high COR as any of the titanium alloys. However, to do that required that no welding touch the back of the hitting face. Hence, by creating a face forging die that would wrap the face piece around in a cup-face construction to allow the welding attachment to be on the top, sole and sides of the body of the head, welding was kept off the back of the face, the face’s deflection capability was maximized, and the high strength steel face construction was able to achieve the same high COR as a titanium driver.

First driver with GRT woodhead face design for more consistent launch angle / 2004 – Wishon Golf 515GRT Drivers

Wishon Golf demonstrated the technical knowledge and the courage to deviate from more than 100 years of tradition in woodhead face design to depart from the old method of vertical roll radius and replace it with a unique vertical face design that ensures more consistent loft up and down the face. As driver heads have grown from 200cc to 460cc in the past 15 years, driver face heights have increased from an average of 1.5” (39mm) to an average of 2.2” (55mm) up to as much as 2.4” (60mm). That means when all other companies choose to use a typical 10” to 12” vertical roll radius up and down the face, the loft of the driver will be as much as 3-4 degrees lower on the bottom of the face and 3-4 degrees higher on the top of the face.

For golfers to achieve a consistent launch angle with such drivers, they have to develop the skill to hit the ball in an area the size of a thumbtack! Wishon Golf’s Graduated Roll Technology (GRT) face design is now incorporated on virtually all of the company’s driver and woodhead designs and delivers a far more consistent launch angle for much more consistent distance and flight for every type of golfer.

Driver with center of gravity more than 40mm behind the face for higher launch angle with higher ball speed / 2004 – Wishon Golf 949G/Ti Driver

In technical publications from its ongoing R&D, Wishon Golf exposed the golf industry to the fact that for many golfers, a rear-located center of gravity (CG) has more of an effect on increasing launch angle than a low CG position. From that, TWGT discovered that it was possible to combine a much more rear-located CG with a conventional loft angle and achieve a higher launch angle previously only thought to be possible from increasing the loft.

By pushing the CG back to an amazing 44mm behind the face in the 949G/Ti driver, Wishon Golf was able to deliver the launch angle of a 12 degree driver with the ball velocity of a driver with a loft of 10.5 degrees. As a result, golfers custom fit to the 949 G/Ti have experienced the best of all worlds – higher launch angle for more carry distance with a higher ball speed not previously possible with that optimum launch angle. The 949G/Ti CG is 6mm (1/4”) farther back from the face than the CG of the Callaway Fusion™ driver and thus stands as the first driver to be designed with the CG more than 40mm behind the face.

First Driver with internal rotating weight arm for Optional CG, Draw Bias, Fade Bias / 2005 – Wishon Golf 715CLC Driver

Weight adjustment drivers that offer a maximum of 24 grams to move around the head will only allow the slightest of visible ball flight adjustment. To a tour pro, a 24 gram movement will create a visible flight change because players of this ball striking skill level have such consistent ball flight that they will notice a 3-4 yard movement of the ball in flight. To the average golfer whose normal ball flight varies from swing-to-swing, no real change will be seen from moving only 24 grams around the outside of the head.

Wishon Golf’s 715CLC driver was designed to allow up to as much as 40 grams of discretionary weight to be moved virtually anywhere around the inside of the head cavity to create custom options for changing the center of gravity position, and from it, allowing the clubhead to perform in a high launch, low launch, draw bias or fade bias manner. Using the 40 gram rotating weight arm, a change of 3.5 degrees in launch angle could be seen between the “at face” to “away from face” positions of the weight arm, and a correction of up to 10 yards of sideways ball movement could be made when the weight arm was rotated into its draw or fade bias positions. The 715CLC departed from the typical moving weight screw design on the outside of the head created by many companies and offered a more dramatic adjustment in ball flight through a much heavier movable weight than used by any other company.

First Driver with CNC machined crown for changing weight distribution, CG/MOI / 2006 – Wishon Golf 949MC Driver

In 1995, Tom Wishon designed the first graphite + metal driver for the purpose of replacing metal with lightweight graphite to more radically move the center of gravity of the head (Power Link Driver – 2005). Few of the large golf club companies did not begin making their version of a graphite + metal driver before 2005. Bonding graphite to a metal woodhead in a hollow shell construction brought with it a greater chance for head failure; the stress of repeated impacts proved to break the bond between the graphite and metal to cause a higher than desired failure rate for such composite and metal heads.

To overcome the higher incidence of head failure but to still be able to remove weight from the top of the driver to facilitate a more rear located center of gravity and higher MOI, Tom developed the process of CNC machining the underside of the top of a titanium driver head to remove the weight necessary for moving the center of gravity and increasing the MOI. Specific areas of the top of the Wishon Golf 949MC driver head which are not subject to high stress were machined 60% thinner than is typical for conventional titanium driver design to accumulate weight which was re-positioned in the rear of the head to achieve the desired rear center of gravity position for higher launch angle and higher MOI for better off-center hit performance.

First Driver to achieve a COR of 0.900 / 2006 – Wishon Golf 0.9OL Driver (developed for foreign markets where the R&A rule for a 0.830 COR limit did not go into effect until 2008)

In his design career, Tom Wishon has always been fascinated with learning how to work with different materials and different face design techniques to increase the amount of face flexing to increase ball velocity for more distance for both on and off-center hits. When the USGA enacted a rule change in 1998 to limit for the spring face capability of clubheads (COR limit of 0.830), the Royal and Ancient Golf Club of St. Andrews, which administers the rules for golfers in other countries, did not ratify the COR limit imposed by the USGA. Only after pressure from the USGA did the R&A agree to institute the 0.830 COR limit for clubheads. But the R&A delayed their enactment of the COR limit for clubheads until 2008.

As a result of numerous requests from Wishon Golf customers in foreign countries and motivated by a desire to see just how high he could engineer the COR of a titanium driver head, Tom relied on his experience in high performance face design to create the Wishon Golf 0.9OL, the first driver head to “reach the 0.900 COR barrier” in the game.

First <200cc Steel Driver with 0.830 COR Face / 2008 – Wishon Golf 525F/D Fairway Driver

It might seem odd at a time when the golf market was not interested in buying steel drivers, let alone one at a small volume/size of 190cc, for Tom to go to work on developing a sub-200cc size driver with a high 0.820 COR face design. The 525F/D was designed as a “Thriver” – a club to use as an alternative to a 3-wood off the tee on tight par-4 and par-5 holes which would generate very close to the distance of a 0.830 COR titanium driver but with better accuracy.

By relying on a cup-face construction with a very high strength steel alloy forged to a thickness of only 1.8mm, the 525F/D was designed at a size of 190cc with a 40mm face height and did achieve the USGA/R&A COR limit of 0.830. As such, the 525F/D became the first steel driver head with a size smaller than 200cc to achieve the spring face limit in the rules of golf.