What the Flex Letter Doesn't Tell You
Flex, kick point, and tempo interact in ways a single letter on the shaft can't capture. Here's what we're actually measuring when a shaft crosses the deflection board.
How the Board Actually Works
A deflection board clamps the butt end of a shaft and applies a fixed weight at a set distance from the tip, then measures exactly how many inches the tip drops. That measurement — not the manufacturer's flex letter — is the closest thing to an objective flex number a fitting bay can produce.
Because the test is standardized, two shafts stamped "Stiff" from two different manufacturers can be measured against each other directly, something a printed label alone can never tell you.
Three Numbers That Change the Whole Picture
Kick Point
Where a shaft bends most under load — low, mid, or high — shapes launch angle independent of overall flex. A low-kick shaft launches higher even at an identical flex rating.
Tempo Ratio
The ratio between your backswing time and downswing time. A shaft that suits a smooth, even ratio can feel unstable for a quick, aggressive transition, regardless of raw swing speed.
Torque
How much a shaft twists under load. Lower torque generally feels more stable for aggressive transitions, while higher torque can add a softer release for smoother tempos.
Steel, Graphite, and Everything Between
Steel shafts measure more consistently shaft-to-shaft and give precise feedback, which is why they remain the default for irons and wedges among players who prioritize feel. Graphite trims weight and dampens vibration, which is why it dominates drivers, fairway woods, and hybrids.
Multi-material shafts blend a steel tip with a graphite body, aiming for the control of steel with reduced overall weight — a growing category we test frequently in iron fittings for players managing joint fatigue.
See Your Own Deflection Numbers
We test flex, kick point, and torque against your own tempo during every fitting session.