I have always been fascinated by product development, specifically the development of unconventional products. Now in the world of golf clubs, one of the most unconventional designs ever introduced was the Cleveland HiBore driver, which during its lifespan, experienced tremendous success through a number of generations, including the HiBore XL, XLS, and finally, the Monster XLS, which, as you may remember, hid the acronym “MOI” on the sole, alluding to its massive level of forgiveness.

As a golfer, I played the original HiBore, along with the XL Tour for a period of time and was always curious about the story behind the “scooped out crown.” In a search for answers, I reached out to Cleveland-Srixon to get the lowdown on the HiBore and discuss where it sits in the pantheon of drivers.

Ryan Barath: Considering how engineers are continuing to do everything they can to increase MOI and push the center of gravity low and deep in driver heads, it feels like the original HiBore and the subsequent models were well ahead of their time from a design perspective. 

It makes logical sense the best way to save weight from the crown is to make the crown “disappear” compared to traditionally shaped drivers, am I correct in assuming that?

Cleveland design team: You nailed it.

At the time of the HiBore, there were really only two solutions to create a low and deep center of gravity:

1. 1. Make the crown lighter – by either replacing the crown with a lighter-weight material such as a graphite composite or magnesium or by thinning out the material on the crown. Thinner crowns were possible thanks to advances in casting technology and using etching techniques to remove material.
   2. Make the driver shallower – this change in geometry created a very forgiving low profile design, but the downside to this was that you ended up with a very small face that looked intimidating compared to the larger-faced drivers on the market.

The HiBore took a new approach and inverted the crown geometry so that all the crown weight was moved lower. By inverting the crown the HiBore design allowed for a very long and flat sole, therefore there was space in the head that was really low and deep to put the weight.

The HiBore was really the first driver to eliminate, or nearly eliminate the tapered skirt. Almost every modern driver in the market is inspired by the HiBore in that respect. It was a two-part solution where we lowered the weight of the crown and simultaneously created a low/deep location to put any extra mass.

The lower and deeper CG of the HiBore improved launch conditions significantly, but also made the driver much more consistent across the entire face. The deep CG increased MOI resulting in tighter dispersion since the sweet spot was in the center of the face. Misses both low and high performed exceptionally as opposed to having a small hot spot high on the face.

RB: In every conversation I have ever had with engineers, there is always this give-and-take mentality from a design perspective to get to the final iteration. Was there anything that was given up or sacrificed for overall performance with this design?

Cleveland design team: The hardest part about the HiBore design was the sound. Prior to the HiBore, internal ribbing in a hollow golf club head was nearly unheard of. To make the HiBore sound acceptable, we had to design a ribbing structure to control the sound and design an entirely new manufacturing process to produce those internal ribs. To this day, most drivers include some form of internal ribbing to control sound or improve ball speed and that ribbing technology can be traced back to the HiBore.

In terms of tradeoffs, the major one was the low spin nature of the driver made it more difficult for low spin players to use. If a golfer is already low spin, this club would be too low and drives would just fall out of the air. Low spin golfers tend to be low spin because they hit the ball high on the face. Since we lowered the sweet spot, a high face impact was further from the sweet spot so ball speed fell as compared to a higher CG driver. Fortunately for us, in that era most golfers were fighting too much spin or way too much spin, this wasn’t a real issue.

RB: Do you have any final words on the HiBore drivers and the legacy they have left behind?

Cleveland design team: We are very proud of the HiBore driver family and the success it had at the time, but we are also proud of its legacy.

In the same way that you can trace nearly every modern band back to the Beatles or Led Zeppelin, you can trace nearly every modern driver back to HiBore either through the internal structure that is prolific across modern drivers, or the long, flat sole that is a must-have in a high-performance driver.