패러랠 아이언 샤프트  vs 동일무게 테이프 샤프트

By Russ Ryden, A Golf Digest America’s 100 Best Clubfitter
Translation by Jae Chang Jo Ph.D.

아이언 샤프트는 두 종류가 있다.  공장에서 이미 팁을 자른 것과 패러렐 샤프트이다.  유니타이즈(Unitized) 패러렐 팁 샤프트는 70년대 초반에 트루템퍼 회사에 의해 소개되었다.

이번에는 두 샤프트의 간단한 설명을 하고 EI 측정으로 논의를 한다.  만약 골퍼이면서 클럽 피터가 아니라면 샤프트의 근본적인 이해를 도울 수 있는 지식을 간략하게 설명하고자 한다.  클럽 피터이라면 패러렐 샤프트의 특성을 이해할 수 있을 것이다.

공장에서 팁트림 샤프트의 셋트  (Trimmed Iron Shaft Sets)

한 셋트의 샤프트를 공장에서 이미 길이에 맞게 자른 이용할 수있다.  셋트의 샤프트는  3, 4, 5 등으로이미 번호가 매겨져 있다.  그 셋트는 1/2 인치 증가하게 되어 있다.  7번 아이언은 8번 아이언보다 1/2 인치 길다.  아래 사진은 4번부터 웨지까지 이다.

  한 셋트 아이언 샤프트에서 팁부터 첫 스텝까지의 거리는 1/2 인치씩 증가하도록 되어 있다.  롱 아이언은  팁이 더 길고 짧은 아이언으로 갈수록 팁이 짧아 진다.  따라서 롱아이언은 짧은 아이언보다 부드럽다.

이것은 셋트내에서 강도의 동시 발생작용을 한다. 즉 롱 아이언의 헤드는 짧은 아이언 헤드보다 가볍다.  짧은 팁과 무거운 헤드의 조합하여  헤드의 무게가 무거울수록 샤프트의 팁 강도는 증가하게 된다.

대부분 공장에서 한 셋트가 길이를 조정한 아이언 셋트는 동일 무게 테이퍼(Constant Weight Tapers)라고 한다. 팁의 직경은 0.355″이며  헤드의 호젤 역시 테이퍼로 되어 있다.  테이퍼 샤프트는 팁을 자를 수 없다.  동일 무게는 모든 번호의 샤프트가 거의 동일한 무게이다.  동일 무게 샤프트는  스윙웨이트 혹은 MOI 매칭을 할 때  샤프트의 무게 중심에 대한 큰 논쟁꺼리가 되기도 한다.

모든 공장에서 팁을 자른 아이언 샤프트가 테이프는 아니며 일부는 패러렐 팁 샤프트도 있다. 대표적인 것은 NS Pro이며 .355 혹은 .370 인치의 팁도 있다.

모든 공장에서 팁을 자른 아이언 샤프트가 동일 무게 아이언 샤프트가 아닐 수도 있다.  트루 텝퍼 XP 및 Dynamic Golf Progressive 샤프트가 짧아질수록 무게는 가벼워 진다.

Parallel Iron Shafts

패러랠(parallel) 아이언 샤프트는 공장에서 단일 길이로 배달된다.  사례로 KBS Tour C Taper Lite 패러랠이  있다.  테이퍼라는 용어는 정확하게 맞는 표현은 아닌데, 패러랠 샤프트의 팁은 .370이다.  패러렐 샤프트는 아이언 번호가 증가할수록 매 번 0.5 인치 팁을 자르고 길이를 맞추기 위하여 버트 부분을 자른다.

이렇게 하면 오른쪽 그림에서 보듯이 Fit2Sore 소프트웨어를 이용하여 그래프로 표현하였다.

자르기 전의 샤프트의 무게는 106 그램이다.  처음 팁 커팅 3번 아이언의 무게는 95 그램이며 연속적으로 1/2 인치씩  팁을 자르면 대략 1.3 그램씩 무게가 줄어들며 웨지는 86.4 그램이 된다.

MOI 혹은 스윙 웨이트 매치된  아이언 셋트는 헤드에 추가적인 무게를 더해야 한다. 패러렐 샤프트의 동적인 무게는 3번 아이언부터 웨지까지는 25%의 무게가 줄어 든다.  그렇지만 동일 무게 샤프트(Taper 샤프트)의 무게 손실은 25%의 절반 정도이다.

전형적인 패러렐 샤프트의 디자인을 살펴 보자.  패러렐 샤프트는 서로 다른 길이를 만들기 위하여 팁을 자르도록 디자인되었다.  이렇게 함으로서 강도는 팁부터 샤프트 중간 부분의 강도가 증가하게 된다.  팁은 샤프트에서 가장 부드러운 부분이다.  팁을 자를수록 샤프트는 강해 진다.

그림을 자세히 보면  샤프트의 밴드 프로화일은 변하게 된다. “Flighted”  샤프트 셋트를 분석하였다.  샤프트가 길어질수록  탄도는 높아지는 경향이 있어 짧은 아이언은 탄도가 낮아진다.  이러한 현상을 “Flighted” 혹은 점진적인 탄도라고 부른다.

KBS Tour Constant Weight Taper 샤프트와 패러렐 샤프트와 밴드 프로화일을 비교하였다. 동일 (constant) 무게 한 셋트에서는 일정하게 강도가 증가하게 된다.  샤프트의 중간 부위에서 팁까지의 강도의 변화는 일정하게 된다.

이러한 관점에서 볼 때, 패러렐 샤프트로 완성된 셋트는 근본적으로 동일 무게 샤프트와 다르다.  동적인 무게의 변화는 완전히 부정적이지는 않다.  “Flighted”  샤프트 셋트를 만들기 위하여 균형이 필요하다.

그렉 노먼은 로얄 프레시션 Rifle에서 다른 브랜드의 동일 무게 샤프트로 바꾸었다고 듣게 되었다. 그는 오랜동안 우승이 없었다.  거의 캐디는 다시 라이플 샤프트로 회귀하자고 권고를 하였었다.  그는 연속적으로 우승을하였다. 이 이야기는 많은 것을 이해하게 되었다. 그래서 패러렐 샤프트를 Fit2Score EI 프로화일 소프트웨어를 이용하여 자세히 관찰하게 되었다. 감탄을 하게 되었는데, 전형적인 패러렐 샤프트 셋트가  바로 “Flighted”이었다.

. 이전의 포스트에서 말했듯이 “모든 공장에서 팁 트림한 아이언 셋트는 동일 무게 샤프트는 아니라는 것이다.  트루템퍼 사의  XP와 다이나믹 골드 프로그레시브 셋트는  짧아질수록 가볍게 된다. “Dynamic Gold Progressive”는  패러렐 아이언 샤프트 프로화일과 비슷하다.  그림에서 무게 번호가 증가할수록 아이언 샤프트의 무게는 줄어든다.  트루템퍼의 XP 115는 무게 감소가 크지 않다.  그렇지만 어느 정도는 롱 아이언에서 웨지까지 탄도가 점차 낮아지는 경향이 있다.

아이언 샤프트의 리뷰는 과거에는  6번 아이언을 대상으로 하였는데 앞으로는  아이언 셋트를 대상으로 분석을 할 것이다.

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TIPPING GOLF SHAFTS

By Russ Ryden, A Golf Digest America’s 100 Best Clubfitter
Translation by Jae Chang Jo Ph.D.

 드라이버 샤프트의 팁을 자르는 작업은 흔한 일이다.This is a quick overview of the effect of tipping.  이글은 팁을 잘랐을 때 결과에 대한 짧은 글이다.  이번 글에서 도표는 3 종류의 샤프트 즉 60 S, 60 X 및 1 인치 팁을 자른 동일한  60 S를 다룬다.  첫번 째 도표는  3 종류의 샤프트 밴드 프로화일이다. 도표에서 팁을 자른 샤프트가 조금 강도가 팁에서 조금 높은 쪽으로 이동한 것을 알 수 있다.  1 인치 팁을 자른 샤프트가   S 샤프트와  X 샤프트 사이에서 작지 않은 강도의 차이를 보이고 있다.

 위의 표에서  각종 수치를 볼 수 있다.  샤프트 버트 강도는 파운드 단위에서 1/10 정도 증가하였고,  토오크는 3/10 도 감소하였다.

팁을 자른 샤프트의 토오크 변화는 상급자는 인식할 수 있는 변화이다.    샤프트를  1 인치 팁 커팅했을 때  토오크 변화는 큰 편이었다.  그 변화는 3/10 도이었고,  1/10 도 변화가 일반적이다.  다시 말해, X 플렉스 샤프트와 비교하면 팁 커팅의 결과는 매우 작았다.

60 S 플렉스의 팁 커팅한  밴드 프로화일 특성(Bend Profile Signature)은 팁에서 버트까지 강도의 변화를 퍼센트로 나타낸 것이다.  팁 커팅한 샤프트 디자인의  EI 밴드 특성은  팁 커팅에 대한 보다 깊은 이해를 보여 준다.

S 플렉스 샤프트와 팁을 자른 샤프트를 비교하였을 때 밴드 특성이 조금 팁쪽으로 이동한 것을 볼 수 있다.  이 샤프트 디자이너는 샤프트 중간부분에서 더 많은 강도의 변화를 주었다.

이러한 중간 부위를 강하게 하는 관점에서, 샤프트의 버트에서 팁까지 강도가 감소하는 것을 볼 수 있다.  그러나 모든 샤프트가 그렇지는 않다.   일부 디자인에서  팁쪽으로 갈수록 강하게 된다.    처음 EI 측정은 팁에서 6 인치에서 시작된다. 그것은 EI 측정할 때 두 점 사이의 중심이  6 인치이다.  그래서 도표에서 6 인치부터 EI를 측정하게 된다.  그래서 6 인치의 값은 샤프트의 팁에서 벗어난 값이다.  샤프트에서 팁은 굵기가 동일한 부위를 말하기 때문이다.도표에 나타낸 샤프트의 디지인은 팁으로 부터 11 인치부터 급격하게 증가하게 된다.   팁 커팅한 샤프트는 강한 부위가 제거되어 원래의 팁 커팅하지 않은 샤프트보다 팁이 부드럽게 된다. 팁 커팅된 드라이버 샤프트는 볼의 탄도에 매우 작은 변화를 준다.  그러나 팁을 자르기 전에 샤프트의 팁의 특징을 알아야 한다.   그렇지 않으면 당신이 기대한 것과 달리 역 효과가 날 수도 있다.

Fujikura SIX DRIVER SHAFTS

Russ Ryden, Golf Digest America’s 100 Best Clubfitter
Fit2Score, Dallas Fort Worth, Texas

The Fujikura SIX is an update and new release of a past Fujikura design. I did not know the original shaft so I cannot comment on the similarity. This short video will give you the history of the design.

As mentioned in the video, it is a classic design. A slightly soft mid in relation to tip and butt. As you noticed in the video, the term soft causes most in the shaft business to flinch. Perhaps some day I will learn to say stiff tip stiff butt rather than soft mid. I start most fittings with a soft mid shaft, it fits most players so it is no wonder this shaft was once popular on tour.

Like all Fujikura Made in Japan shafts, the label sits directly on one of the FLO planes and has some lines to indicate such. The graphics align with one of the FLO planes. The radial consistency of the review samples was very good, averaging 98.8% with a 0.6% standard deviation. Orientation in a rotating hosel is not an issue with this shaft.

I see a mid launch, mid spin design. when trimmed, this shaft will weight in the high 50g range. That is a range I have become very comfortable fitting recreational golfer with. It is a weigh range I am now playing.
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Measuring the Golf Shaft(골프 샤프트 측정하기)

By Russ Ryden, A Golf Digest America’s 100 Best Clubfitter
Translation by Jae Chang Jo Ph.D.

몇 년전 본인은 샤프트 디자인을 하는 업계에 근무하는 엔지니어로부터 EI 용어에 관하여 배웠다.  대부분 EI 측정장비는 미화 만불 정도이었으며, 대부분 피터에게는 저렴한 것이 아니었다.  심지어 대부분 샤프트 회사 마저도 장비가 없었다.  그럴듯한 EI 장비를 설계하는데 2년이 걸렸다.

몇 년간 사용한 후 디자인을 다시하는 등 장비를 개선하기로 결심하였다.  개선된 버전 7의 Fit2Score Ei 장비는 지금 이용가능하다.  아래 동영상에서 샤프트를 측정하는 모습을 볼 수 있다.

장비는 정밀도와 재현성을 개선하기 위하여 재 설계되었다.

핀을 이용하여 정확하게 무게 추를 장비에 설치할 수 있게 하였다.  새로운 무게 추를 장비에 장착하였다. 이전 장비는 새로 설계된 부품으로 업그레이드할  수 있다.

새롭게 디자인된 자동 중심 샤프트 지지점은 이전 기기와 호환성이 유지되고 있으며  반면 샤프트의 중심을 안내하는 것을 제거하였다. 샤프트는 자연스럽게 위치하여 측정값을 빨리 그리고 반복적으로 읽을 수 있다.

 고리 강도(Hoop Strength) 측정 장치가 추가되었다.  11 KG 무게와 0.0001 인치의 깊이 측정기를 이용하여 고리 강도를 측정한다.  새로운 드라이버 데이타 베이스에는  길이 방향으로 7 개 지점에 대한 고리 강도의 값을 저장한다.  이러한 측정은 샤프트에 대한 이해를 돕는다.  고리 강도는 다시  다루기로 한다.  * 고리 강도(Hoop Strength)는 샤프트에 무게를 적용하였을 때 타원으로 변형되는 반지름의 감소를 측정한다.

EI 측정장비는 $ 2,200에 구입가능하다.  엑셀 기반의 데이타를 수집하고 샤프트 프로화일을 분석하는 S/W가 포함되어 있다.   소유자는 지식 기반의 사이트에 자신의 분석 자료를  구독할 수 있다.   이 장비에 대한 흥미가 있다면  russ@fit2score.com으로 문의하면 된다.

Iron Golf Shafts – KBS TOUR 105

By Russ Ryden, A Golf Digest America’s 100 Best Clubfitter
Fit2Score, Dallas Fort Worth, Texas

The KBS Tour 105 Constant Weight Taper released in August 2015. The label looks much like the KBS 105 Parallel that is offered in the 2015 Taylor Made RSi irons, the shaft is not. The KBS Tour Taper 105 is generally stiffer and has a firmer tip than the TaylorMade only KBS 105 Parallel Shaft.

My fitting experience has taught me that the 105 to 115 gram weight range is the best fit for most amateur golfers. My understanding from the tour fitters is that this range is rapidly gaining traction among professional players as well. The KBS Tour iron shaft profile is not new. It is available in two 90 gram versions and the ‘standard’ version that ranges from a 110 gram R to a 130 gram X in 5 steps, 5 gram increments. The Tour 105 overlaps that range as seen in the table below. It comes in 5 gram increments, a 108 gram R, a 111 gram S and a 117 gram X. The 111 and 117 are much the same as the same weight KBS Tour shafts.

Radial consistency is 99.8% with a 0.2% standard deviation. Do not waste your money or time aligning these shafts. It will not make any difference, they are perfectly round. As you can see, weight equals stiffness, the S and X simply weigh more and are stiffer with exactly the same profile shape.

The set profile shows a very slight amount of flighting. The shaft bend profiles are much the same throughout the set. The tips of the longer irons are slightly softer in relation to the rest of the shaft than the shorter irons. And that indicates slightly higher launch propensity in the longer iron shafts.

When I started fitting, many years ago, I learned shaft profiling with a frequency instrument. I will not go into the discussion of that system here more than to say it focused entirely on matching 6 iron shafts to each other as the method for understanding iron shafts. After I created an affordable shaft EI instrument I began looking at the bend profiles of all the shaft in a set of shafts. I quickly became aware that not all sets of iron shafts have the same bend profiles throughout the set. We do not play 6 irons only, we play sets and an important understanding of iron shafts are the set profiles. In the illustration above you see the enhanced profiles of the 3i, 6i and wedge shafts of the KBS Tour 105 S iron shaft set. And you can see a small difference between the shafts in the set. The tips of the short iron shafts are stiffer relative to the rest of the shaft than the long iron shafts. EI stiffness profiling extends to the very tip of the shaft. The legacy frequency profiling method is accurate at 17 inches from the tip, marginal at 11 inches and cannot read below that. It simply cannot reveal what you see above.

Lets take a closer look at the difference between two similiar sets the KBS Tour 105 S and the KBS CTaper Lite 110 S, These are the raw graphics available in the Fit2Score shaft software. Look closely at the two sets as they scroll. The steepness of the Tour profiles indicates a higher launching design than the CTaper. This is validated in years of fitting experience. If you need launch assistance, use the KBS Tour models. If you want to keep the ball flight down, use the C Taper models. Once you learn the relationship of the profiles to ball flight, you can easily predict performance by looking at the EI charts.

Now look closely at the difference between the profiles of the short and long irons in the two sets. You will see a flatter short iron vs long iron in the C Taper profiles than in the Tour set. This is what is referred to as a flighted set. Neither set is intentionally flighted, but one would expect the CTaper Set to deliver lower, more piercing short iron trajectories than the Tour set. And this is precisely why it is important to know set profiles not just 6 irons when fitting irons. The KBS Tour model will flight high throughout the set while the C Taper will offer some assistance in launching the long irons while keeping the short iron trajectories lower. Which is best is simply a function of your individual style. Knowing the profiles, your fitter can match you to the iron set that enhances your game.

Modeling Static Load Deflection(정하중 휨의 모델링)

By Russ Ryden, A Golf Digest America’s 100 Best Clubfitter
Translation by Jae Chang Jo Ph.D.

샤프트의 차이를 이해하기는 결코 쉽지는 않았다.  휨(bending)은 빔의 특정 지점의 탄성계수 E와 단면 관성모멘트 I 의 산물이다.  식은 아래와 같다.

w는 빔의 휨이며, X는 위치, K는 곡면이다.  이것들은 샤프트 설계자에 의하여 사용되는 기초 과학이다.  샤프트 설계자가 샤프트의 디자인을 이해하기 위하여 동일한 시스템을 이용한다.

나의 친구이자 기술적인 멘토인 데이브 투텔맨과 작업에서, 본인은 샤프트 지식 기반에 대한 휨의 모델링을 추가 하였다.  휨은 EI로부터 계산할 수 있다.  드라이버 샤프트의 36 지점의 EI의 이해로  휨을 무게 즉 변수로 모델링할 수 있다.  아래 왼쪽 그림에서 두 종류의 샤프트 Ei를 보여주고 있다.  오른쪽 그림에서 샤프트에 하중을 실었을 때 휨을 모델링하기 위하여 서로 다른 무게를 샤프트에 적용하였다.

샤프트의 EI 프로화일을 값을 알기 위하여 두 종류의 샤프트를 선택하였다. 이들 샤프트는 제조사가 S 플렉스로 분류하였다.   EI 프로화일에서 버트 및 팁의 강도는 거의 동일하였다.  그렇지만 디플렉션을 측정하였을 때 서로 많이 달랐다.

오른쪽 그림에서 디플렉션 보드에서 샤프트의 휨을 볼 수 있다.사진은 골프웍스 것을 차용한 것이다.  이것은 샤프트의 휨의 특성 및 강도를 이해하기 위하여 사용되는 오래된 장비이다.

이제는 디플렉션 보드가 CPM 측정 장비로 대체되었다.  CPM 측정 장비는 클럽 메이커에게 강도를 수치로  알려 준다.   CPM 측정기는  디플렉션 보드에서 보여 주는 밴드 프로화일은 알려줄 수 없다. 디플렉션 보드의 결점은 밴드 프로화일을 계량화할 수 없으며,  클럽 메이커에게 휨의 특성만 보여줄 뿐이다.

EI 값을 이용함으로서 휨 프로화일을 계산할 수 있으며 수량화할 수 있다.   EI는 샤프트 기술자에게 샤프트의 벽의 두께, 직경 및 테이프 감소율 등의 재료 특성을 이해를 할 수 있게 한다. 모든 주요 골프 샤프트 회사는  샤프트의 원형을 개발하기 전에 그들의 아이디어를 모델링하기 위하여 SW를 만든다.

본인의 EI장비는 사용하게 될 샤프트의 모델링을 쉽게 할 수 있게 한다.   EI 측정기를 보유한 클럽 피터는 피팅할 샤프트의 휨의 특성을 이해할 수 있다. 

이러한 이해는 샤프트를 측정하기 위하여 왜 이러한 장비와 시스템이 필요한가에 대한 답이다.  이 사이트의 저자들인 피터는 이러한 관점에서 그들이 피팅할 샤프트를 잘 이해하고 있다.

스윙 중에 적용되는 부하는 샤프트의 휨으로 변환된다.   이러한 휨은 스윙 중에 느낌이다. 느낌에 대한 피드백은 스윙에 관한 타이밍을 도와준다. EI 밴드 프로화일은 휨의 크기를 뿐만 아니라 휨의 형태를 결정한다.  휨의 형태는 스윙과 샤프트의 상호작용에 의하여 임팩트 때 공의 탄도 등에 영향을 미친다.

TIPPER UN SHAFT DE GOLF

By Russ Ryden, A Golf Digest America’s 100 Best Clubfitter
Translation by Herve Francillon, BackSpin Fitting, Draguignan, France

Il est courant de Tipper les shafts de driver. Voici un aperçu rapide de cet effet. Les diagrammes montrent trois shafts, un 60S, un 60X et un 60S tippé de 1″. Le premier graphique montre les différents profils de ces shafts. Remarquez le léger changement au bas du shaft ‘Tippé’. Pas de changement de profil, simplement un léger gain de rigidité. Sur ce modèle, tipper 1″ représente qu’une faible différence entre les flex S et X.

On peut clairement voir cela en chiffres. La rigidité au butt augmente de 1/10, le torque lui de 3/10 de degré.

L’effet sur le torque avec ce modèle montre un changement intéressant pour un bon joueur. Ce shaft a l’un des plus gros écart que j’ai jamais mesuré avec 1″ de Tip. 3/10 de degré alors que généralement je constate seulement 1/10. Cependant, le fait de tipper ce shaft de 1″ n’induit qu’une faible différence comparé au même modèle mais plus rigide.

Le profil du shaft nous donne encore une indication sur le fait de tipper un shaft. On ne remarque qu’un léger changement entre la version 60S tippée et l’original par rapport au même shaft en 60X. L’ingénieur a clairement choisi un changement de profil au milieu du shaft le plus rigide.

Dans les exemples précédents, on a vu un shaft où la rigidité décroit du butt jusqu’au tip. Ce n’est pas le cas de tous les shafts. La rigidité de beaucoup de shafts actuels augmente au tip. Notre première mesure est effectuée a 6″. Mais on mesure le flex à partir de 1″ jusqu’a 11″ pour le shaft ci-contre. Si le diagramme ne montre que le profil à partir de 6″, le flex est mesuré au bout du shaft. Sur ce design de shaft, on peut voir que le shaft devient plus rigide à partir de 11″et ce jusqu’au tip. Tippé ce shaft réduit alors la rigidité et rend le shaft plus souple que le shaft non tippé !

Tipper un shaft de driver a un léger effet sur le vol de la balle. Cependant, on doit connaitre les caractéristiques du bas du shaft avant de le tipper. Vous pourriez parfaitement créer l’inverse de l’effet désiré.

Certification d’un set de fer par le EI Profile
Que cache le “Frequency Matching”

By Russ Ryden, A Golf Digest America’s 100 Best Clubfitter
Translation by Herve Francillon, BackSpin Fitting, Draguignan, France

On me demande souvent si je construis des séries en Frequency Matching. Ma réponse est non, Frequency Matching tel quel est un concept louable. L’armonisation des fréquence est réalisée en contrôlant un seul point de fréquence proche du butt et on dit que la série est réglée si la fréquence suit une progression linéaire. Cependant, contrôler un seul point ne garanti pas que le reste du shaft, et spécialement autour du tip, est ‘cohérent’. La technique de mesure Fit2Score, mesure le shaft tout les 2 inchs, confirmant qu’une série de shafts utilisée sur vos fers est constante du tip au butt. On contrôle le torque, le poids, l’équilibre et la constance.

Un autre préjugé est l’alignement du shaft. Depuis longtemps ma position est que si un shaft nécessite un alignement pour être joué, il ne devrait pas être utilisé. Si il est normalement rond, un alignement est un perte de temps et d’argent ! Mais, ‘la rondeur’, la constance du shaft doivent être contrôlées pour que votre série soit homogène.

Les images ci-dessous sont issues de l’évolution du programme Fit2Score pour le montage d’une série de fer et la validation du logiciel de shaft. J’ai longtemps utilisé une version personnelle. Ca a été amélioré pour la rendre plus conviviale. De nouveaux rapports ont été crées. Un rapport sur une série de shaft de fer rassemble plusieurs données tel que la consistance, la rigidité, le poids, l’équilibre et le torque. Cela a été mon mode de construction de toutes mes séries pour des joueurs à un chiffre depuis plusieurs années. Parmi toutes les séries haut de gamme,  une sur quinze avait des valeurs incohérentes. C’est souvent un point faible à un endroit du shaft. Cependant, dans certains cas ces valeurs semblaient venir de nulle part !

Cet ensemble de vues montre une série KBS Tour V, en commençant par le Regular à 100g et finissant avec 2 versions ‘tour’, le 125 et le 130g en XStiff. Les deux dernières illustrations montrent le KBS tour XStiff et le KBS CTaper XStiff. C’est une représentation intéressante des shafts de chez KBS.

Chaque séries montrent une uniformité parfaite en tout point. Les Profils augmentent progressivement en rigidité du wedge aux fers les plus longs. La forme des courbes ne change pas sur toute la série. Vous pouvez envisager une performance constante sur toute les séries de fers construites avec ces séries de shafts.

Sivous êtes novice avec ce système de mesure, vous remarquerez qu’on le fait sur toute la longueur jusqu’au bout du shaft. La première mesure est relevée à 6″. La courbure mesurée est de 1″ à 11″ à partir du bout du shaft. On mesure en fait la partie du shaft qui est concernée durant l’impact. Vous pouvez entendre que d’autres systèmes sont plus précis. Cependant, l’expérience nous a appris que l’on ne peut pas mettre une charge de plus de 11kg à 10″ sur des shafts légers sans les endommager. Cette charge devrait alors être moindre dans les autres systèmes, rendant de ce fait incohérant ce qui semble un avantage en regardant simplement les formules de profil.

La déflexion a longtemps été utilisée par le clubmaker comme une façon de comprendre les shafts. Le shaft est maintenu au butt ou au tip et un poids est accroché de l’autre côté. La flexion du shaft a longtemps été utilisée comme mesure de la rigidité d’un shaft. Les graphiques au dessus montrent une table de déflection. C’est tiré des mathématiques en appliquant une charge au shaft. la courbe de chaque section du shaft est calculée suivant la charge appliquée et la distance de cette charge. Chaque courbure de toute ces sections sont alors mises bout à bout pour créer une vue générale de la courbure du shaft. Ci-dessous, le graphique de deux shafts avec différentes charges appliquées en bout illustre comment un shaft pourrait se charger durant un swing de golf. EI profil peut montrer le comportement dynamique d’un shaft de golf

 프리퀜시 매칭을 넘어서, EI 프로화일 아이언 샤프트

By Russ Ryden, A Golf Digest America’s 100 Best Clubfitter
Translation by Jae Chang Jo Ph.D.

만약 내게 누군가 프리퀜시 매칭 아이언 셋트를 준다면 바로 거절할 것이다, 그것은 구시대 유물이기 때문이다.

프리퀜시 매칭은  샤프트의 버트 단일 부위에서 점검하여 만들어진다. 그러나 단일 부위의 점검은 샤프트 나머지 부분도 동일하다는 것 보장하는 것은 아니다. Fit2Score의 EI 측정 장비는 2 인치 증가하면서 측정하기에  한 셋트의 아이언 샤프트는 팁 부터 버트까지 측정의 일관성을 보장한다.  토오크, 무게, 균형점 및 방사 방향의 온전함까지 측정한다.

또 다른 오랜 개념은 샤프트의 정렬이다.  샤프트가 정렬(스파인 개념)은 필요하지 않다는 것을 입장을 지금까지 견지해 왔다.  그것이 필요하다면 시간 낭비일뿐이다.  그러나 샤프트의 완전함 혹은 방사 방향의 온전함은 한 세트 안에서 샤프트의 일관성을 보증하기 위하여 반드시 점검하여야 한다.

아래의 그림은 Fit2Score 아이언 셋트 조립 및 샤프트의 검정 소프트웨어의 개선을 시험하기 위한 것이다.   본인은 몇 년동안 이 시스템의 개인 버전을 사용해 왔다.  현재 사용자 편의를 위하여 세밀하게 개선하였다.   아이언 셋트의 증명 보고서는 샤프트 셋트에서 방사 방향의 온전함, 플렉스, 무게, 균형점 및 토오크에 관한 많은 것을을 아울러게 되었다. 지난 몇년동안 최 상급자 골퍼를 위하여  아이언 셋트를 내 기준의 표준으로 제작하였다.  높은 품질의 15 셋트 중 1 셋트 정도에서  결함이 있을 정도이었다.  그것은 샤프트의 길이 방향의  일반적인 오차이다.그러나  어떤 경우도 샤프트의 결함은 희귀한 사례이다.

분석은 KBS 투어 V의 100 그램 R 플렉스와  두 종류의 투어 버전으로  X 플렉스의 125 그램 및 130 그램 샤프트이다.  마지막 2 페이지는 KBS 투어 X와 KBS C-Taper X이다.  분석 보고서는 독특하고 흥미로운 KBS 아이언 샤프트 패밀리를 대상으로 하였다.

샤프트들은 완벽하게 동일한 양상을 보여주고 있다. EI 프로화일은 일관성있게 웨지부터 롱 아이언 샤프트 까지 강도가 증가하고 있다. 프로화일 커브의 모양은 셋트내에서 어떤 샤프트도 변화가 없다.  따라서 KBS 샤프트의 아이언 셋트내에서 일관성있는 퍼포먼스를 기대할 수 있다.

만약에 이러한 측정 시스템을 처음 대하였다면 모든 것은 팁부터 시작한다는 것을 그림에서 알 수 있다.  처음 측정은 6 인치부터이다.  빔의 사이는  팁의 1 인치부터 11 인치이다.  외팔보를 이용한 또 다른 장비가 더 정확하다는 것을  들은 적이 있을 것이다.  실제로 EI 공식은 이러한 사실을 믿게 만들었다.  11 KG 무게를  경량 샤프트의 10 인치 사이에 샤프트의 파손없이  무게를  얹어서 이러한 사실을 알게 되었다.

휨은  클럽 메이커가 샤프트를 이해하기 위하여  사용되고 있었다. 샤프트를 버트 혹은 팁에 고정하고 다른 끝 쪽에 무게를 매달았다. 샤프트의 굽음의 정도를 샤프트의 강도측정으로 이용되고 있었다.   샤프트의 설명서에는 이러한 휨의 도표를 보여 주고 있었다.  이것은 샤프트에 대한 수학적으로 무게를 적용한 것이다.샤프트의 각 부위의 휨은  적용된 부하와 부하로 부터의 거리로 계산하였다. 이러한 각 부분의 휨을  샤프트의 휨의 복합적인 도표로 만들었다.   아래의 그림은  서로 다른 부하를 샤프트의 팁에 매달아 표시한 그림이다.  마치 스윙중의 휨과 비슷할 수도 있다.  EI 프로화일은 샤프트의 동적인 휨을 정의하는 것이다.

Nippon Modus3 Tour 125 Iron Shaft

By Russ Ryden, A Golf Digest America’s 100 Best Clubfitter
Translation by Jacobo Canal Vila

Una nueva varilla, la tercera en la línea Nippon Modus3, se lanzó en EEUU en Mayo de 2015, y está disponible en los Distribuidores Autorizados de Nippon. Eché mi primer vistazo a un par de ellas utilizadas en la PGA Mechandise Show hace dos meses. El perfil se me describió como una mezcla de las otras dos versiones. Nippon ha puesto un sustancial conocimiento técnico en el material y la fabricación de estas varillas. Aquí tenemos una mirada a los perfiles de tres varillas de la familia Modus3.

Como me dijeron, la Modus3 125 se encuentra entre los otros dos diseños. La calidad radial de las muestras era excepcional, 100%. No consideréis nunca alinear estas varillas, son perfectas.

La varilla está marcada como se muestra en esta foto. Llevará el logo del System3 Tour 125. Cortar a la longitud estándar la convierte alrededor de 120 gramos. No es el típico peso amateur en estos días. Se encuentra en el segmento de la parte alta (referido a términos de peso), dónde encajo yo a la mayoría de los golfistas. Es un perfil que se parece mucho a Dynamic Gold X, con una punta ligeramente más rígida. Estoy anticipando una propensión baja al lanzamiento.

Una mirada rápida a las curvas de deflexión nos muestra las diferencias en los modos de flexión S de estas varillas. Usando los valores de las secciones de estas varillas, cargamos la varilla matemáticamente para trazar el modo en que se dobla bajo cargas en punta y en extremo. La carga en el extremo ocurre al principio del swing, en la punta ocurre más tarde.

Este perfil complementa a la familia Modus3, ampliando el rango de encaje y sensaciones de alguien que ha crecido con Dynamic Golds. Los perfiles de la varilla Modus3 al final del set, en el hierro 3 y en el wedge, muestra un cambio en el perfil para favorecer un vuelo más alto de bola con los hierros largos.

Iron Golf Shafts – Matrix Program F15

By Russ Ryden, A Golf Digest America’s 100 Best Clubfitter
Fit2Score, Dallas Fort Worth, Texas

The Matrix Program iron shaft has been with us for some time. The 2015 Matrix Program F15 is a subtle evolution of what has been a very successful shaft. Matrix, acting on club builder input, creating balance points in this version of the Program that will easily build into D2-D3 swing weights. The earlier Program shafts were white. If you had tested the Program and liked it, as many did, you lived with the white. The change to a neutral color, a shiny silver gray, removes an entry barrier for many.

The Matrix Program F15 is available in three weights, 80, 95 and 125 grams. As is typical with most shafts, weight and stiffness are interrelated. One thing you will notice when handling this shaft is the wall thickness. In carbon fiber tubes, wall thickness creates hoop stiffness and torsional rigidity. The Program F15 has both, the torque numbers are as low as it gets, and the hoop stiffness negates any possible ovalizing during the golf swing. That means the head is going to follow your hands. When you square off you hands the head is going to follow. The impact wave coming up the shaft is solid thud.
Radial integrity is very good, the FLO differential is 99.5% with a 0/6% standard deviation. I still get questions from golfers about shaft alignment. These shafts, like most premium shafts currently available, will not benefit from alignment. Remember, your golf club rotates about 180 degrees during a golf swing. Where in that swing should to dominate plane be aligned. Is it better that the shaft not have a dominate plane to start with?

The EI profile is unusual for parallel shafts. Most exhibit a uniform butt, a zone of descending stiffness in the mid, and a uniform tip. Trimming creates a slightly flighted set, as the tips get shorter. The article on Parallel shafts explains this in detail. 

The Matrix Program F15 EI profile descends uniformly from butt to tip. The effect can be seen here with the virtual trimming modeling of the Fit2Score shaft profiling software. This creates a trimmed set with uniform profiles. As the shafts get shorter the profiles remain the same. The entire shaft gets stiffer from butt to tip throughout the set. To the club fitter and builder, this is yet another example of the importance of looking at iron shafts as sets. Shaft profile software that looks at 6 irons only cannot see this aspect of set makup. If you are looking for penetrating ball flight, typical of constant weight sets, on your long irons you will like the Matrix Program F15’s.

Nippon N.S.Pro Modus3 Tour 105

By Russ Ryden, A Golf Digest America’s 100 Best Clubfitter
Fit2Score, Dallas Fort Worth, Texas

The N.S Pro Modus3 Tour105 was released to the US public in August 2015. I had seen a set of these earlier in the year, labeled Prototype ST. The Modus3 Tour 105 is the same shaft that has been available on tour for several months. The word Prototype has been replaced with Modus3. I have been told it was put in play by a number of players. Lighter weight iron shafts are gaining broader acceptance in the tour community. In a slightly different form, this shaft has been with us for quite some time. The Modus3 Tour 105 is very similar to one of my long time favorite shafts, the N.S.Pro 1050. Lets look at the charts and numbers:

As you can see, the profile of the Modus3 Tour 105 is very close to the N.S.Pro 1050. The flexural signature shows It is a little softer in the butt and stiffer in the tip than the 1050’s, tilted in such a way to slightly lower launch. The set is slightly flighted. At this weigh range, these could become a very popular shaft. The N.S.Pro 1050 is one of my fitting favorites. I regard this weight range as a sweet spot for many golfers. We are looking at an update to the Nippon line, bringing the Modus style graphic to a very successful design.

Radial consistency of the Modus3 our 105 were perfect, averaging 99.9% with virtually no standard deviation. Any form of shaft alignment of these is a waste of time and money.

Studying the measurements very closely, what looks to be very similar EI profiles are subtly different. The Modus3 Tour 105 R & S flex models appear heavier only because the uncut shafts are 2″ longer. The stiffness as measured on a deflection board are softer, but the tip to butt rations are much higher. That means the tip stiffness is closer to the butt stiffness. That indicates lower launch. For a detailed discussion of reading launch from EI profiles read Understand Golf Shaft EI Profiles at Fit2Score. If you are a club fitter or club builder and would like to see more in depth information about golf shafts, subscriptions to the Fit2Score shaft profiling software are now available.

The English Nippon Shaft site has been significantly updated recently. The update shows and explains the EI profiles of the Modus products. The section of that site that discusses EI profiles is excerpted below.  When one of my fitting associates happened on it, I got a call telling me they copied my graphics. I had to explain, sorry, in fact, they were first, I copied them. Nippon and the other major shaft companies have designed and manufactured shafts with 3 point EI software for decades. It is only now, that the golfer and club makers are developing literacy in the language  of the shaft engineer.
Nippon is one of the few shaft companies that has for many years explained and defined their products to club fitters with EI graphics. The other is Mitsubishi Rayon. The 2015 Fujikura shaft product brochure does the same. This is the language by which one can under the subtle nuances of today’s shaft choices.

Project X Loading Zone Driver Shafts

By Russ Ryden, A Golf Digest America’s 100 Best Clubfitter
Fit2Score, Dallas Fort Worth, Texas

The Project X LZ, or loading zone shaft features a linear soft zone in the middle of the shaft which is visibly reinforced with bias wraps to maintain torsional stability. This 2014 composite driver shaft from True Temper, released under the Project X brand, is made in limited numbers in the USA facility in San Diego California. I am told only 60 or 70 can be made in any given day with current staffing.

This is an interesting option now being offered by a few companies. The general golfing public has access to the shafts that are made in the tour department for the tour players. Most graphite shafts are hand rolled. As such, the care taken by the person putting the shaft together is reflected in the quality and consistency of the finished shaft. Almost every company has some highly skilled wrappers that make their prototypes. And very often, when these people are not making protos, they are making the shafts that go to the professional tour vans. These shafts are not necessarily better than the shafts made in the volume production shops, but they are free of the shaft to shaft inconsistencies found in the factory produced product. And I have seen some inconsistencies that are hard to believe from the high volume, low cost foundries, but that is another story.

The concept of the Load Zone was to create a soft midsection in the shaft. Mid soft shafts are among the most popular shaft in my fitting experience. No shaft company likes to hear a section of their shafts being discussed as soft. If you make the tip stiff and the butt stiff, the mid is soft in relation to those other two zones. In the Project X Loading Zone shaft, the soft mid section is reinforced by a material called flex lock. That is graphite fiber oriented on an angle from the length of the shaft, commonly refereed to as bias or hoop plies. This stabilizes the torque in this zone. A full discussion of the design is shown in the videoed discussion I had with Don Brown, the True Temper graphite shaft product development manager.

Radial integrity averaged 99% with a 0.6 standard deviation. These shafts can be oriented in any direction in rotating hosels. The Loading Zone shafts are counterweighted, with high balance points. A good match to the bling heavy driver heads that dominate the 2014-15 market. The GJ torque profiles were linear. The soft mid zones, stabilized with the flex lock material did not exhibit a significant drop in torque from the zones closer to the butt of the Project X Loading Zone Shafts. As shown in the averaged EI profiles, the shafts could be sorted into three distinct design groups. Sorted by flex, not illustrated, the position of the loading zone is centered across the 50, 60 and 70 g versions. Sorted by weight, the loading zone moves toward the tip and gets shorter as the stiffness increases. This is very interesting matrix of shafts for the fitter working with a client that fits into a mid soft design driver shaft. it illustrates the importance of working with a fitter that ‘knows’ the EI profiles of the shafts he works with.

This is an interview shot at the 2015 PGA merchandise show in Orlando. Don Brown is the Graphite Shaft Product Development Manger for True Temper Sports. The discussion of the Loading Zone Shafts gets technical. Many readers of this site tell me they do not understand some of the graphics and discussions in my reviews. What you see in this video is a discussion using the terms you see on this shaft review site. Enjoy!

FlightScope Monitoring
Project X Hand Crafted Loading Zone Driver Shafts

The images to the left are FlightScope acceleration charts. FlightScope radar tracks the clubhead as well as the golf ball. The head is picked up about 45 inches from impact. The FlightScope operator is presented with a large array of information to use in the club fitting process. I pay close attention to the stability and repeatably of the acceleration chart. We can see the hump in the chart, release, shifting further away from impact as the weight of the shaft increases. The combination of increased stiffness from the additional weight and the weight induced change in release manifested into a change in launch angle. The table below shows how this influenced ball flight.

Weight of the shaft and weight of the club head are key components of golf club fitting. Your sweet spot, the weight that creates the most stable speed and path can only be found by a fitter equipped with shafts and heads in various weights.

In this and future reviews we will be looking at deflection of the shaft derived from the EI profile. By looking at tip loading we see how the shaft bends from the weight of the head magnified by its speed and acceleration. The butt loading deflection shows how the shaft bends from the force applied at the handle. The 50 gram shafts are significantly easier to load from the butt. The 60 and 70 have much the same butt loading character, differing more at the tip, where the 70 gram shafts, designed for higher speeds have more tip stiffness and a lower launching propensity.

Grafalloy ProLaunch Driver Shafts

By Russ Ryden, A Golf Digest America’s 100 Best Clubfitter
Fit2Score, Dallas Fort Worth, Texas

The Grafalloy Prolaunch is not a new design, it has been with us for a long time. It got a new paint job this year. As companies get better at making shafts, the quality and consistency of products gets better. What I saw in measuring a the $40 ProLaunch Blue and Red was beyond what I expected. Radial consistency was 98.9% with a 0.8% standard deviation. These shafts are round and will get no benefit from alignment. And the bend profiles were also consistent. There were no outliers in the 10 shafts I measured. That is not always the case, and it is rarely the case with a $40 shaft. I am impressed.

Beginning with this review I am introducing a new method for rating shaft stiffness. The method comes from inside one of the major club companies that has an EI measuring instrument. They use area under the EI curve to compare shaft to shaft stiffness. Frequency measured at the butt of a shaft works on shafts with the same bend profiles. When shafts have different bend profiles butt frequency does not give an accurate measurement. Have you ever heard or said, ‘this shaft plays softer (or harder) than it measures. Did it ever occur to you that you were basically saying the measurement system you were using does not work?

Using area under the EI curve takes into account every point of the shaft. The correlation with deflection measurements is incredibly high. It appears that we have stumbled on a shaft stiffness rating system that actually works.

Grafalloy rates the launch of the Blue as higher than the Red. Look at the chart above and you will see that with the same stiffness rating the Red deflects less than the Blue. The launch rating given by Grafalloy is validated. The more expensive, $80 Grafalloy Blue is also rated low launch and is validated by the deflection numbers. It has a stiffer tip, pushing the kick point up the shaft. Radial quality of the Grafalloy Blue, 99.6% with a standard deviation of 0.5%. Translation, great quality and consistency and a notification to the shaft business that quality is possible in affordable products.

Grafalloy Prolaunch Supercharged Drive Shafts

By Russ Ryden, A Golf Digest America’s 100 Best Clubfitter
Fit2Score, Dallas Fort Worth, Texas

The Grafalloy Prolaunch Blue and Red Supercharged drive shafts are 2015 additions to the ProLaunch product line. They are $60 shafts with radial quality of 98.3% with a standard deviation of 0.6%. If you have not been reading this site and looking the radial quality numbers I will translate this for you, one word, impressive. Shaft to shaft consistency of the review sample profiles was equally impressive. I did not think a $60 shaft would get my attention. I was wrong.

If the $300 to $500 high end works of shaft art technology are not in your budget, try the Grafalloy Prolaunch Supercharged in your driver. You are going to give up some hoop stiffness and might experience some ovalizing. If that is a problem you can always get a similar design in the Project X LZ for around $350. The SuperCharged Prolaunch has a similar design to the handcrafted Project X LZ shaft, an active midsection. Does this design work for you? If you are not close to a fitter that can let you test the Project X LZ you can try a low cost test on your own with the ProLaunch Supercharged shafts.

The Blue is a higher launch design, the Red a lower launch.  To my eyes they are much the same profile. The Red is heavier and stiffer. The bend point is higher. Those two properties are going to lower launch. This is not really complicated stuff to understand. Stiffer is lower for any particular golfer. Find the stiffness you feel you can load. Then, going a little softer or stiffer will move the launch up or down.

Look at the balance in this chart. These shaft are counterweighted to restore club balance when using the current generation of heavy driver heads. This is not seen at this price point.

This profile, a softer active midsection is gaining traction with the shaft companies. With this set of profiles, this particular pattern got my attention. Soft midsections are among the most popular shafts in the business. Exaggerated soft is a design I am beginning to see from a lot of shaft companies. it looks like one needs to go in my bag.

Graphite Design Tour AD M9003 Driver Shaft

By Russ Ryden, A Golf Digest America’s 100 Best Clubfitter
Fit2Score, Dallas Fort Worth, Texas

The Graphite Design Tour AD M9003 released in mid 2015. It is an unusual addition in that it is only available in 4 models, 60 and 70 S and X. With a $550 MSRP, this is not a shaft for any but the strongest fastest golfers. Graphite design is not recommending it for anyone south of a 105 mph driver swing. That excludes me. It is made with high modulus 55 ton, Nanoalloy prepreg from Toray. Translation, the material in this shaft is as good as it gets.
Radial consistency is 98.9% with a 0.2% standard deviation. Like all Graphite Design Tour AD shafts, it is round and will play exactly the same in any orientation.

The closest match to this shaft from Graphite Design is the Tour AD BB, a shaft that was released around 2011. The Tour AD BB is one of Graphite Design’s popular shafts on the professional tours and gets a lot of play on the LPGA. The profiles are similar until we get to the tip.
Starting around 17″ from the tip, the M9003 goes stiffer than the BB. It starts with a softer butt section, giving it a higher tip to butt ratio. For those of you that don’t look at these numbers like a shaft engineer does, a higher ration of tip to butt stiffness means lower launch and lower spin. If you are looking for a shaft that will help you get the ball in the air, look elsewhere. If you have the speed to launch and are looking for a shaft designed to keep your drives from drifting upward, take the Tour AD M9003 for a test drive. Bring a swing, this shaft demands one.

And while you look at these profiles take note of the way the mid section drops below the trend line. That seems to be a trend with a lot of shaft designs lately. Must be something to it when it starts showing up as often as I see it lately.

Graphite Design Tour AD GP Driver Shaft

By Russ Ryden, A Golf Digest America’s 100 Best Clubfitter
Fit2Score, Dallas Fort Worth, Texas

The Graphite Design Tour AD GP releases in a few days. New carbon fiber materials are being continuously developed. In the Tour AD GP, Graphite Design is using TORAYCA ® T1100G carbon-fiber pre-preg with NANOALLOY ® technology according their release information. This gives the shaft a stiffer tip without a change of weight that would typically be associated with tip stiffening by simply adding material.

Looking simply at the bend profile I see yet another driver shaft with a stiff tip and stiff butt or put another way, a soft mid. In my experience that is a very popular profile. It is being refined and offered in many more manifestations than the early days of premium shaft designs. But before we begin that discussion, lets take a look at the measurements of the Tour AD GP.

The radial consistency of the review samples was 99.1% with a 0.4% standard deviation. I have never actually seen a bad shaft from Graphite Design. Ever. They check the stiffness on both FLO planes and discard the bad shafts. Shafts are mostly made by hand. Not every shaft comes through the wrapping, baking and sanding process perfectly. The difference between shaft companies is what process they use for deciding what gets shipped and what goes in the trash. Graphite Design has very high standards. They only ship the shafts that pass through what must be a very high quality standard. I have not witnessed the process but I have witnessed the result.

In looking at the chart above take note of the tip torque numbers. There is a very small number of shafts in the sub 60 gram category that have 3 degrees or less of tip torque. If you are wondering what the TORAYCA T1100g pre-preg brings to the Tour AD GP you can see it here. Low tip torque in a shaft with a moderately high balance point. In comparison with the BB, the balance actually moved a bit down the shaft. For the club builders reading this, this is one of that category of shafts that should not be tipped. It gets stiffer starting at about 12″ up the shaft. If you tip it, you will be moving that soft spot closer to the tip. Not a good idea. In fairways, use a heavier stiffer shaft. My advice, DO NOT tip this shaft unless you intend to make the tip softer.

Looking simply at the bend profile I see an update of the ever popular Tour AD BB. Looking at the 60g S flex, comparison to the right, the tip is ever so slightly stiffer. There was some fine tuning in the tip torque area. The 50’s are slightly higher, the 60’s about the same and the 70’s slightly lower than the Tour AD BB. Tip torque has a great deal to do with feel. Moving it 0.1 degrees defines fine tuning. No one other that the Tour players are going to notice.
The soft mid is moved closer to the handle. This should get a little more load into the shaft with a smooth controlled transition. The overall tip to butt ration is a bit higher as shown in the deflection profile. It will launch a litter higher and feel a little softer than the BB. I see it as a refined update to that shaft. We will have it out on the range soon with a pro that has been playing a BB for some time now. Stay tuned for an update .

Shafts Fers – KBS TOUR 105

By Russ Ryden, A Golf Digest America’s 100 Best Clubfitter
Translation by Herve Francillon, BackSpin Fitting, Draguignan, France

Le KBS Tour 105 à poids constant est sorti en Août 2015. L’étiquette ressemble en tout point au KBS 105 Parallèle proposé sur les fers Taylor Made RSi, le shaft non. Le KBS Tour 105 conique est globalement plus raide et a un Tip plus ferme que le shaft KBS 105 Parallèle que l’on peut trouver sur les Taylor Made.

Mon expérience du fitting m’a appris que les shafts compris entre 105 et 115 grs étaient le meilleur la gamme qui fittait le plus grand nombre de golfeurs amateurs. Les fitters du tour m’ont dit que cette gamme de poids gagne beaucoup d’intérêt auprès des joueurs pros. Le profil de shaft n’est pas nouveau. On peut le voir sur les deux versions à 90 grs et sur la gamme standard KBS Tour qui va de 110 grs Reg au 130 grs Xstiff. Le Tour 105 s’intercale donc comme indiqué dans le tableau ci-dessous. De 5 grs en 5 grs, à partir de 108 grs en R, 111 en S et 117 grs en X. Les 111 et 117 sont quasi les même que les déjà connus shafts  KBS Tour de même poids.

La constence est de 99.8% avec une déviation de 0.2%.Dépensez pas votre argent ou votre temps à aligner ces shafts. Ca ne fera aucune différence, ils sont parfaitement ronds. Comme vous pouvez le voir, poids égal rigidité, le X est simplement plus lourd et plus raide que le S avec exactement le même profil.

Le profil du set montre une très légère tendance ‘flighted’. Les courbes sont sensiblements les même sur tout le set. Les bas de shafts sur les longs fers sont légèrement plus souples par rapport aux fers les plus courts. Cela montre une tendance de vol un peu plus haut sur les shafts de fers longs.

Quand j’ai commencé à fitter il y a plusieurs années, j’ai appris les profils de shaft avec une machine à fréquence. Je ne rentrerai pas ici dans une discussion sur ce système mais dire que ce système sert simplement à mesurer et comparer des shafts de fer6. Après avoir créer un instrument à mesurer les profils de shaft, j’ai commencé à étudier les profils de tous les shafts d’une série. J’ai rapidement compris que pas tous les sets de shafts de fer ont le même profil sur toute la série. On ne joue pas que des fers 6, on joue des séries et il est important de comprendre les profils de shaft sur une série. Dans le graphique dessus vous voyez les profils des shafts de fer 3, 6 et wedge d’un KBS Tour 105S. Et vous pouvez voir une légère différence entre les shafts. Les bas de shafts des fers les plus courts sont plus raides par rapport aux shafts les plus longs. Le profil de rigidité s’étend jusqu’au plus bas du shaft. Un profil en fréquence n’est précis que jusqu’à 17 inch du bas, marginal à 11 inch et impossible à lire au delà. Il ne peut simplement pas révéler ce que vous voyez au dessus.

Jetez un coup d’œil sur la différence entre deux sets KBS Tour 105 Stiff & KBS CTaper Lite 110 Stiff. C’est une vue que vous pouvez voir grâce au logiciel Fit2Score. La pente plus prononcée du Tour 105 indique un lancement plus haut que le CTaper. Si vous avez besoin de plus d’angle de lancement, orientez vous vers les modèles KBS Tour. Contrairement, si vous avez besoin d’une balle plus basse utilisé le CTaper. Une fois compris la relation profils / vol de balle, vous pouvez facilement prévoir les caractéristiques simplement en regardant les diagrammes.

Maintenant observez la différence entre les profils des shafts de fers courts et de fer longs dans les deux séries. Vous pourrez y voir un profil plus plat sur les fers courts / fers longs sur le CTaper que sur le KBS Tour. Voilà ce qu’on appelle une série ‘flighted’. Aucunes séries n’est intentionnellement ‘flighted’, mais on peut s’attendre à ce que le CTaper donne une trajectoire plus basse et plus pénétrante sur les fers courts que le KBS Tour. Et c’est la raison pour laquelle il est important de connaitre le profil de la série et non pas simplement du fer 6 quand on fitte des fers. Le KBS Tour volera plus haut et ceux, sur toute la série alors que le CTaper vous aidera à lever la balle sur les fers longs et aura une trajectoire plus basse pour les fers courts. Quel est le meilleur ? C’est simplement une appréciation personnelle. En connaissant les profils de shafts, votre fitter pourra vous conseiller au mieux pour votre série de fer.

ACCRA FX Driver Shaft

By Woody Lashen, A Golf Digest America’s 100 Best Clubfitter
Pete’s Golf, Mineola, New York

ACCRA introduced the FX product line in 2015. There are 4 versions, FX1, FX2, FX3 and FX4. The FX line of shafts replaces the Dymatch line for Accra.  Quality has always been excellent in Accra shafts and it moves to the top of the class with the FX line. The FX 200,300 and 400 are made in Japan in a small boutique manufacturing plant.  This divers line allows us to fit many different players in to the FX series.   Accra’s concept was to have one family of shafts but with 4 different profiles. With the FX 100 being the highest launching shaft, FX 200 mid launch, FX300 low launch and the FX 400 lowest.  (Note the 400 only comes in X flex).  Along with each profile there is Fairway woods and hybrid shafts designed to play the same as the driver shaft.  This is rare in the shaft industry; most shafts are designed for drivers only.  Accra found that on Tour it was rare for a player to use the same shaft in there fairway or hybrid as in there driver so they designed a shaft line that would allow the Fairway and hybrid shafts to feel and play the same as the driver.  They had great success with this technology in the Dymatch series and the FX picks up with they left off, but even better quality.

The ACCRA FX1 series is a high launch design. That can is seen in the tip to butt rations as well as in the calculated butt loaded deflection graphic show above. They are not as stiff as the FX2, 3 or 4 models, by design. Roundness, or radial consistency averaged 99.0% with a 0.6% standard deviation. Balance is neutral.

The 100 series fits best for slow to medium speeds and tempos.  With 3 weight options for the driver it covers a lot of players.

The ACCRA FX2, FX3 and FX4 bear the notation Made in Japan. They follow the ACCRA CS1 as premier examples of how attention to detail will create shafts that are consistent and orderly progressions from weight to weigh and flex to flex. A golf club fitters dream set of shafts. Roundness of the review samples averaged 99.5% consistency with a 0,2% standard deviation. By design, they launch lower than the FX1 series.

As speed and tempo rise the 200 and 300 come more in to play or those needing medium launch.  The 400 is only for the rare player with high speed and tempo, however that player will really enjoy its stability.

Woody Lashen co-owner of Pete’s Golf talks with Gawain Robertson co-owner of Accra Golf shafts talk about the FX series shafts.

Adjusting 3 Point Bend Measurements for Tube Deformation

By Russ Ryden, A Golf Digest America’s 100 Best Clubfitter
Fit2Score, Dallas Fort Worth, Texas

In several research papers on golf technology 3 point bent testing is faulted for failing to account for tube deformation under load. With the assistance and coaching from Dave Tutelman I began a year long study of the issue. That study is now in its final phase and I have corrected the measuring process to compensate for tube deformation. This illustration showing a cross section of the shaft measuring graphically illustrates the issue.

Figure 1:  The typical 3 point measuring system uses a gauge positioned at the top of the shaft. A preload is applied to the shaft, and the measuring gauge is set to zero.

Figure 2:  When load is applied to the shaft, It bends. Golf shafts are hollow tubes, not only do they bend, they also deform becoming oval. Deformation is a function of the hoop strength of the shaft. In linear bend testing, the oval deformation is a source of error. We want to measure the bending of the centerline of the shaft. We actually measure bending at the top of the shaft.

Figure 3:  In this illustration, the ovalization of the shaft is vastly exaggerated. The top to bottom dimension of the loaded shaft changes by 50 units. Half of that dimension, 25 units is the error of the measurement at the top of the shaft.

Figure 4:  The correction; subtract half of the deformation, 25 units from the top of shaft deflection. In this exaggerated illustration, the centerline deflection of 15 units is the difference between the top of shaft deflection, 40 units and half the ovalization, 25 units. The corrected measurement, 15 units is the actual bending of the shaft.

Figure 5:  This is a prototype EI instrument built for researching and understanding tube deformation during 3 point loading. A gauge under the shaft measures deformation at the bottom wall. The difference between the top and bottom gauge is ovalization of the shaft. A third gauge measures deformation at the beam support. After studying many shafts, we can now forecast deformation from hoop stiffness alone. 

The ovalizing of the shaft shown above is exaggerated for the purpose of the illustration. In fact it is typically less that 2% near the tip and as much as 20% near the butt. The correction does not change the shape of the EI graphics. It does modify the slope. The butt section of shafts is revealed as stiffer than uncorrected top wall deformation data. As you can see here, the subtle stiffness changes shown in inch by inch 3 point profiling are apparent in both the uncorrected and adjusted graphics. Those stiffness bumps that are the essence of feel and performance are apparent in both graphics. The adjusted graphics will make butt stiffness more accurate going forward.

The three gauge instrument shown above was built for research and is time consuming to use. However, we knew at the onset of this research project that deformation was going to correlate to the hoop strength measurements we are already taking.

Applying a multiplier to the hoop deformation we have been measuring corrects the EI data. In this illustration you can barely see a difference between the measured deformation and the calculated deformation. The measured deformation is done at the supports and the press. The hoop deformation is done under the press, applying the load to the shaft while it is firmly supported on a block of metal.

This should forever end the critique of the accuracy of 3 point measurement of golf shafts. I am indebted to my friend Dave Tutelman for his guidance and assistance as we worked on this project for over a year.