Shaft marketing is dense with numbers that mean different things at different companies. This page is the reference sheet we would hand a client who wanted to understand the choice rather than just accept it.
If you only get one shaft decision right, make it weight. Weight sets how much effort it takes to move the club and how much feedback you receive about where the head is. Flex adjusts the fine behaviour on top of that, and no flex rating rescues a shaft that is twenty grams wrong for you.
The reason weight matters more is that it changes the sequencing of your motion. Too light and a lot of golfers get quick from the top because there is nothing to sense; too heavy and the club drags behind the body and arrives late and open. Both problems show up as a directional miss that looks like a swing fault.
We test weight before anything else in every session, usually by holding the model and flex constant and only moving through the weight range. It is dull to watch and it settles the biggest variable in under twenty shots.
There is no industry body defining what "stiff" means. One company's S is another company's R and a third company's X, and the differences are not small — we routinely measure a thirty cycle spread between two shafts wearing the same letter.
| Label | Frequency we usually see | Who it tends to suit |
|---|---|---|
| Ladies / L | 255 – 275 CPM | Slower tempo, lower clubhead speed |
| Senior / A | 270 – 290 CPM | Smooth loading, moderate speed |
| Regular / R | 285 – 305 CPM | The largest group of amateur golfers |
| Stiff / S | 300 – 320 CPM | Faster transition or higher speed |
| Extra Stiff / X | 315 – 340 CPM | Aggressive transition, high speed |
Notice the overlaps. A firm R from one maker and a soft S from another can measure within two cycles of each other. This is exactly why we put a frequency analyser on candidate shafts rather than trusting the print, and why a set built from mixed sources needs checking before it can be called matched.
Two shafts of the same weight and the same measured stiffness can behave completely differently depending on how that stiffness is distributed along the length. This is the part of shaft selection that most reliably surprises people during a session.
More bend near the tip generally means the head arrives with a touch more dynamic loft, producing a higher launch and often more spin. Useful for a player who struggles to get the ball airborne; unhelpful for someone already launching high and spinning.
Resists bending late in the downswing, which tends to hold launch and spin down. Suits a golfer with an aggressive transition who is fighting a ballooning flight, and can feel harsh to a smoother swinger.
The butt section governs a lot of what you feel rather than what the ball does. A softer handle reads as smooth and lively; a firmer one reads as solid and communicative. Neither is better, and this is where personal preference legitimately outranks data.
Measured in degrees; lower numbers twist less. Lower is not automatically better. A low-torque shaft in the hands of a moderate-speed player feels boardy and dead, and the golfer loses the feedback that tells them where the face is.
Two shafts weighing the same can carry that weight in different places along their length. A tip-heavy shaft raises swing weight for the same total mass, which changes how the finished club feels even though the spec sheet looks identical.
Cutting material off the tip end stiffens the tip section, sometimes substantially. This is why the same shaft model can play noticeably different in two builds — and why we follow the manufacturer trim chart for the exact model rather than a generic rule.
An iron set built from off-the-shelf assemblies will usually show an irregular frequency progression — the 6-iron a touch soft relative to its neighbours, the 8-iron a touch firm. Each club is within its own tolerance, but the set as a group is not consistent.
The consequence is subtle and real: one or two clubs feel like they belong to a different set, and golfers compensate for them without realising. Lining the set onto a single frequency slope removes that.
It is not free. Achieving it takes tip trimming decisions made club by club and occasionally a shaft rejected and re-ordered. It is included in any full iron build we do rather than sold as an upgrade.
More on Iron SetsSpeed is one input. Two golfers at the same speed with different transitions need different shafts, and the charts cannot see transition.
Occasionally it helps at the margin. Far more often the hook is a face and path issue, and a stiffer shaft simply makes the club harder to hit.
Plenty of golfers in their seventies play better with a heavier shaft because it slows their transition and improves their sequencing.
Tour builds are assembled around swings almost nobody reading this has. The shaft is right for them, which tells you nothing about you.
Reading about bend profiles is a poor substitute for feeling three of them in the same head, one after another, with the numbers on a screen.