CERTIFICATIONS


SHAFT STIFFNESS PROFILES

DIFFERENCES  IN DRIVER SHAFTS -- FITTING MATTERS

 

Quintic 4.4R Accredited Center

    Putter fitting        San Francisco

Authorized Dealer

 

 


Authorized Miura Dealer in San Francisco

MOI-MATCHED CUSTOM FIT WITH THE RIGHT SHAFT FOR YOUR SWING.

We are a featured dealer and fit with the full range of Miura clubs.

SHAFTS

 


 


GOLF CONDITIONING
Monday
Jul032017

The 19º 4-iron

The 19º 4-iron is decreasing loft disease out of control. That's the loft of this long iron in a new iron set from a leading club manufacturer who markets the increased distance their clubs can yield. The loft of the 6-iron is 25º, the 7-iron loft is 28.5º.

Claims of distance increases achieved by these new OEM irons are understandable if the low lofts are factored into the discussion. Loft is the main determinant of distance in iron performance -- it's basic physics. When you want to compare performance of different clubs, make certain they have the same loft and same shaft to get meaningful results.

Clubhead lie angles are 1º - 2º high through much of this new set. Loft differences between clubs at the short end of the set are 5.5º. It is an easy argument to make that this "game forgiving" set will be a game wrecking set since the golfers who need help will struggle with many of these irons.

There is an abundance of plastic incorporated into the cavity back and into multiple slots cut into the club head. The vibration damping effect of this much plastic can have an unfriendly result for many golfers, especially with a graphite shaft. Loss of feel of the ball impacting the club face makes it more difficult to achieve ball-striking feedback that otherwise would help with swing technique improvements. 

We call attention to these issues because a common complaint from golfers is that they can't hit their long irons with any consistency, and they are uncomfortable with any club lower than a 7-iron. It's not surprising when clubs have distorted loft and lie angle specifications.

Our advice, find a qualified club fitter and be sure to test classic iron designs with premium shafts that are matched to your swing. We are certain they will out-perform any "game improvement" set.

Thursday
Jun082017

Clubs or Lessons First?

The uncertainty implied in this question arises from the fallacy that equipment can be separated from technique. The problem is exacerbated by playing mass assembled off-the-rack clubs manufactured with shafts and club heads of questionable quality and inefficient design. Unstable shafts and inefficient club head weight distribution are common problems.

Golfers usually approach the performance dilemma by attempting swing changes without understanding their swing tendencies or determining whether the clubs adequately fit their swing mechanics. The frequent results are increased tendencies at address towards closed grip, closed stance, and forward shaft lean that limit any hope of achieving an effective swing. Swing mythology further complicates achieving performance goals.

Fortunately improvements in materials and design together with modern analytics can help resolve the dilemma. The importance of stable shafts without excessive weight cannot be over-emphasized. Substantial improvements in graphite materials and manufacturing together with an understanding of how they affect EI stiffness distribution have major impacts on performance. 

Similarly, club head materials and engineering design are more important than marketing claims to club performance. Physics matters -- e.g., the only way to make your 6-iron perform like a 5-iron is to produce or bend it to a stronger loft. And, it's difficult to adjust the lie angles of you irons and wedges if they are cast from hard brittle alloys.

Here is our bottom line recommendation. Start with premium upgrade-quality shafts properly fit to your swing. Forged irons and wedges give you the best options for fine tuning adjustments that meet your needs. Subtle refinements in driver and fairway wood design and materials can result in substantial performance enhancements.

Allow sufficient time for professional club fitting -- a couple of hours minimum -- with a radar launch monitor. Golfers have unique swing tendencies that affect club performance in subtle ways that are only revealed by launch monitor technology and high speed video. Rely on direct measurements. Charts and tables can be useful as guides but they are not a substitute for hands-on testing and evaluation. Fitting and swing expertise matter more than a wall of colorful shafts.

Monday
Nov072016

Shaft Flex Rating

Flex is a general term for describing shaft stiffness. Simple rating systems have been used to indicate stiffness. The most common rating system is the LARSX classification: Light (soft flex), Amateur (moderately stiffer than L), Regular (intermediate flex), Stiff, Extra stiff. Alternative terms, e.g. Ladies, Senior, Firm, Tour Stiff have also been used.

There are no industry-wide standards for flex since each manufacturer uses their own measurement protocols. R-flex in one brand can be S-flex or A-flex in a different brand. Some companies go a step further by changing the flex ratings for shafts between their own model lines. How did flex ratings get into this mess and what does it mean for golfers?

An early system still in use today for estimating flex is to weigh shafts. A heavy steel shaft has a stiffer flex than a lighter weight shaft in these models. The problem with this static measurement is that it does not account for loading and unloading of shaft energy during the swing. Variables like shaft diameter, wall thickness, taper of the shaft from grip end to tip, weight distribution through the shaft are ignored.

In the 1970's Joe Braly at Brunswick Golf/Precision Golf introduced a numerical system to describe shaft flex. It depended on a technique in which a shaft is clamped at the butt end, a standard weight attached to the tip end, the tip deflected then released, and shaft oscillation frequency measured. The data correlated with empirical findings on the relationship between flex preferences and swing speeds of pro golfers with their irons.

Here's an example of how this number system was related to swing speed for a 5-iron built to standard weight and length, as extrapolated from Brunswick/Precision's Fitting Guide. Subtract a Frequency Coefficient factor of 30 from the measured swing speed, then use 10% of this value to define the shaft flex. For example, an 85 mph clubhead speed would yield a 5.5 flex number. 

Frequency Coefficient Matching (FCM) became the basis for building a flex-matched set with Rifle shafts, and a similar fitting system was developed by True Temper for Black Gold shafts. The PCS clubfitters group adapted the concept but made arbitrary changes that generated different flex numbers. This system was extended to a 3-number system for indicating stiffness of butt, mid, and tip sections of shafts following general guidelines described by Wishon Golf.

Unfortunately single letter, single number, and 3-number rating systems based on frequency measurements place excess emphasis on the butt end of the shaft where the large diameter yields the stiffest flex. Details in the distribution of stiffness through the length of the shaft are obscured by clamping effects and tip weights. However, shaft oscillation methods can be useful in identifying planes of flex stability.

Analysis of shaft loading characteristics and the refinement of production methods and materials have allowed modern shaft engineers to design shafts with variable stiffness regions along their length by varying shaft diameter, wall thickness, elasticity of materials, and manufacturing technologies. Different regions of stiffness can be designed at local regions of the shaft to achieve major effects on feel and performance.

Shaft wall elasticity (E) and resistance (mechanical inertia) (I) to strain can be measured along the length of the shaft for graphs that indicate stiffness in a meaningful way. In this technique a calibrated weight is lowered onto a shaft resting between two support points and resistance to the weight is measured by a strain gauge. Repeating the measurement at short intervals (e.g. 1") indicates local stiffness at multiple points through the length of the shaft.

Basic EI analysis shows that stiffness distribution can vary substantially among shafts having the same flex ratings as determined by oscillation-frequency clamp methods. EI graphs reveal subtle as well as major regions of stiffness variation engineered into the shafts by design and manufacturing. These variations are not revealed or even hinted at by simple letter or number rating systems.

The EI graph of stiffness distribution versus length shown here and on our website home page illustrates four "R-flex" shafts with dramatically different EI profiles that were selected on the basis of having identical R-flex frequency measurements. Golfers will feel different degrees of stiffness and control depending on how they load swing energy through the downswing and impact zone.

Bottom line is that stiffness is a complex property of a golf shaft that cannot be adequately described by single letter or simple number systems in their various forms. Fitting and buying clubs with a reliance on retail flex ratings has little value if maximizing shaft performance for an individual golfer's swing mechanics is a goal. The great value in professional club fitting shows personal testing to identify the right combination of shaft and clubhead for each golfer is by far the best strategy in optimizing clubs.

Monday
Aug222016

Club Head Speed

Club head speed at impact with the golf ball is the main factor in determining ball speed and distance achieved. The faster you can swing the club, the longer the ball will fly. Hit the ball straight with good impact quality and the ball will gain more distance, the holy grail of driver performance. It also matters for irons.

Greater clubhead speed is helped by having less weight in the club, and it's achieved most easily by using a light weight shaft. New graphite fiber formulations have yielded exceptionally stable super light weight stable shafts for drivers. Similarly, new steel alloys and manufacturing methods have improved lightweight stable steel shaft playability. 

Not all lightweight shafts are created equal. Differences in the distribution of stiffness (EI) and weight and materials strength through the length of the shaft are important in matching shaft responsiveness to a golfer's swing mechanics. Quality of materials and shaft production consistency also matter.

Most golfers are conditioned to the generalization that high torque shafts are "whippy" or too soft and difficult to control at any swing speed. While it was true for many early production shafts produced with generic graphite materials that made them flex like fishing rods, those days are long gone.

Current lightweight graphite shafts made with premium composite mixtures and unique construction methods can be engineered for unprecedented stability while retaining great feel and balance. Many pros today on the major pro golf tours win with graphite shafts in their irons.

Similar arguments apply to steel shafts for irons. Modern lightweight steel made with premium alloys and updated production methods can yield responsive shafts with exceptional stability that outperform heavy rebar-like stiff steel shafts in common use today. It translates into consistency of performance and feel that you experience on the course and at the practice range. 

Clubs with lightweight shafts yield the best performance when their overall club balance complements the swing. It's a function of differences in the way golfers transfer energy to the club during the downswing. Each golfer responds uniquely to the feel of the shaft, the weight of the club head, and the overall balance of the club. Getting these adjustments optimized in club fitting translates into improved distance and accuracy.

Wednesday
Aug102016

Wedge Shaft Fitting 

Wedge fitting is typically incomplete. The focus is almost entirely on features of the club head, e.g. loft and lie angles, sole grind, bounce, leading edge, weight, etc. It's the heart and soul of wedge fitting. But too often, that's where it stops.

The effects of the shaft on how wedges play and feel are generally ignored. Consequently heavy, stiff shafts that can feel like rebar are often used. It keeps costs low but degrades performance. For those of us who don't reach the green in regulation, pairing the right shaft with the right head and best sole grind can be a game changer.

Why be concerned about shafts in your short game clubs? Wedges are used in about 20% of the shots in a typical round for every golfer at all skill levels. With putting contributing to 40% of a typical score, it's easy to conclude that wedges account for one-third of all shots made from everywhere on the course that isn't a putting green.

As with all other clubs, wedge performance is enhanced by improving the feel of a shaft. It is a major factor in how a golfer responds to a club during the swing. Shaft feel reflects distinct characteristics engineered into the shaft including stiffness distribution, torque, materials, shaft wall properties, and the way weight distribution and total weight affect overall balance.

In our experience. all golfers, from beginners to advanced can feel subtle differences between shafts. Starting with a soft-forged wedge clubhead and a large group of distinct shaft options, the best combination for every golfer can be identified. Launch monitor data quantifies trajectory and shot distribution to help guide the selection. 

The roots of developing improved feel in wedge shafts came from professional golf. Tour players wanted a shaft that delivered increased ball spin, had more weight with a softer feel, and greater control over ball trajectory. The Precision Golf "Spinner" shaft was the first successful response to that request. It was a specific design not a generic shaft that's quite different from the current replacement.

Today there is a whole world of choices for wedge shafts designed to match your distinct ball flight and performance goals. Shaft manufacturers are taking advantage of new materials and production methods to offer several different models for customizing a wedge to exactly the feel and control that matches a player's game. 

For all clubs, the shaft that works best with any player can only be determined by direct testing. No chart, forum post, or marketing brochure can substitute for your individual response to a wedge in chip shots, lob shots, and full swings. We find that personal testing of different shaft designs is a key part of finding the right wedge for the benefit of your short game.