The Myth: How a Shaft Feels is Defined by a Single Letter

When golfers hear "flex," they often think of a single letter—R, S, X, etc.—but flex is relative to the specific shaft model and profile. The flex rating of one shaft model isn’t necessarily the same as the flex rating of another, even if they share the same letter designation. This is because flex is not just a measure of stiffness; it's also influenced by the shaft's bend profile—how the shaft bends in different sections (tip, mid, and butt).

At Nippon Shaft, we take a unique approach through full profile tuning. Each shaft model is engineered to offer specific performance outcomes based on how we adjust the flex in the tip, mid, and butt sections. For instance, a model like the MODUS³ TOUR110 may have a progressive stiffness from the tip to mid sections for control and stability,

while a model like the Zelos 7 might feature a softer tip/mid section for a more responsive feel without sacrificing on dispersion with a firmed up tip section. 

This comprehensive design philosophy ensures that each shaft feels and performs uniquely, even within the same flex category. We tune the profiles differently to achieve the desired outcomes of launch, spin, and feedback.

How to “Feel” a Profile

While swing robots provide measurable data, most fitting happens in the hands of golfers—feel is crucial to finding the right shaft. Here’s how you can “feel” the difference between profiles, even without advanced equipment:

Eliminate Variables:  To truly isolate the shaft's influence, try a fitting kit with the same head and multiple shaft options. This removes the variability caused by different head weights or designs. Keeping the grip and length consistent is equally important to avoid altering feel from the shaft alone.

Maintain Consistency in Loft and Lie:  Ensure the loft and lie settings are the same across all test clubs. These settings directly impact how the shaft interacts with the ball at impact, so keeping them consistent helps isolate the differences in performance and feel based on the shaft profile alone.

Test Feel, Don’t Just Guess: Ultimately, the best way to feel a profile is to test it in real-world conditions. Even with modern fitting technology, there’s no substitute for actually hitting different shots with different shafts to see how they feel during your swing and in various conditions.

Observe How the Shaft Reacts: Pay attention to how the shaft loads during the transition (the change in direction as you approach impact), and at impact (where the shaft releases its energy). Depending on the shaft's profile, these stages will feel different—some shafts may feel more active and responsive, while others might feel stiffer or more stable.