When I entered the golf club fitting business about 15 years ago, there was not a standard rating system for golf shaft stiffness. Nor was there a way to compare golf shafts. This journal gives you a way to compare golf shafts with a uniform stiffness rating evaluation. Understanding the properties of a golf shaft which is your best fit leads to a better game.

Describing golf shaft properties is not a simple task. Shaft company marketing developed terms, “kick point”, “stiffness”, “launch” and “spin” to describe shaft properties. These terms developed into a mythological language for describing golf shafts. Shaft engineers and designers define golf shaft stiffness as a profile, the change of stiffness down the length of the shaft. Many years ago a tour of a shaft company R&D lab enlightened my understanding of golf shaft technology.

That lead to me designing and manufacturing a very accurate shaft stiffness measuring instrument. It is now used by several shaft companies. I have been writing about shaft properties for 10+ years. The term EI profile, is now part of the discussion some shaft companies are having with golfers.

If you want to understand golf shafts you have come to the right place. Here you can learn why some shafts work better for you than others. And more important, how to recognize the properties of shafts that make you a better golfer. Please share your comments about what you experience with the shafts reviewed.

A system which defines the distribution of flex down a golf shaft is how most shaft companies design golf shafts. But the information, for fear of giving that information to their competitors, is not shared with the public. It took a few years to refine my measurement instrument and many, many years to acquire and measure the popular golf shafts. This journal provides you with uniform measurements of thousands of golf shafts. If you are new here, the TECHNOLOGY MENU is a collection of articles that will guide your understand golf shaft design.

This journal is entirely supported by subscription. To insure my integrity, there are no ads on this site, that allows me to remain unbiased in the articles. If you believe as I do, that your golf shafts are essential to good golf, please subscribe. Acquiring shafts, measuring them and writing articles takes a great amount of time. Your subscription underwrites the time and resources needed to keep this journal going and growing.

This video is a detailed discussion about golf shafts stiffness and the history of how they were measured and marketed. It is one of many videos about golf equipment technology and golf club building on my youtube channel, Devoted Golfer.

It took years to understand shaft measurement and many more years to accumulate a meaningful database of shaft measurements. The magnitude of that accomplishment did not occur to me until a golf shaft company owner said it to me. Several golf shaft companies now use the EI measuring instrument I designed and manufactured. If you are a golf professional and would like access to more data there are two choices. Golf Professional subscribers get access to a larger set of data and individual profiles of all the shaft model weights and stiffness variations that were made available. Fit2Score Affiliates have access to the entire database through Excel. To hear a podcast interview I did about golf shafts with Tony Wright, a Fit2Score Software Affiliate, Click Here.

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Nippon Modus3 110 Iron Shaft Review

By Russ Ryden, Fit2Score, A Dallas Fort Worth Club Fitter & Builder
The Highlands Performance Golf Center, Carrollton Texas 
Golf Digest Certified America’s 100 Best Club Fitter

The Nippon Modus3 110 is the third Modus3 shaft from Nippon ending with a 0. First was the 120, then the 130, now the 110. The moniker is a rough approximation of the weight, but also an reference to a unique bend profile from Nippon. Those shafts ending with a 5 are the same profiles with the numbers, 105, 115 and 125 indicating weight. In the Modus3 110 family, the weights range from R at 103g, S at 109g and X at 114 grams. Weight directly correlates to stiffness as it does in all steel shafts.

To continue reading this section of the review, you must be registered at a higher level membership.
Russ

autoFlex Dream7 Shaft Review

Korean Hidden Technology autoFlex Dream7 Driver, Fairway and Hybrid Shafts

By Russ Ryden, Fit2Score, A Dallas Fort Worth Club Fitter & Builder
The Highlands Performance Golf Center, Carrollton Texas 
Golf Digest Certified America’s 100 Best Club Fitter

Korean Hidden Technology autoFlex Driver shafts came to the US market several years ago. I saw one in 2021. They cause a sensation with a $790 price point. They were very light weight and started a trend for light weight driver shafts. Ultimately most US golfers were not ready for light weight shafts at that price point.
The autoFlex Dream7 is a second generation autoFlex. It is lighter than the original model made with updated Japanese prepreg and 2nd generation Korean Hidden Technology. According to KHT the Dream7 has a new tip section to enhance impact performance.

To continue reading this section of the review, you must be registered at a higher level membership.
Russ

autoFlex Joy365 Golf Shaft Review

Korean Hidden Technology autoFlex Joy365 Driver, Fairway & Hybrid Shafts

By Russ Ryden, Fit2Score, A Dallas Fort Worth Club Fitter & Builder
The Highlands Performance Golf Center, Carrollton Texas 
Golf Digest Certified America’s 100 Best Club Fitter

Korean Hidden Technology AutoFlex Driver shafts came to the US market several years ago. I saw one in 2021. They caused a sensation with a $790 price point. They were very light weight and started a trend for light weight driver shafts. Ultimately the recreational US golfer was not ready for light weight shafts at that price point.
I met with Korean Hidden Technology at the PGA 2025 merchandise show and shot an interview in their booth. It is on the list of videos that need to be published. They followed up with a shipment of review samples of every SKU they make. I don’t see much difference between the Joy365 and the original autoFlex shafts. The autoFlex website tells us the Joy is made with updated prepreg. the measured differences are subtle. Without hitting them I cannot comment on feel.

To continue reading this section of the review, you must be registered at a higher level membership.
Russ

autoFlex Korean Hidden Technology Shaft Review

Korean Hidden Technology autoFlex Driver, Fairway and Hybrid Shafts

By Russ Ryden, Fit2Score, A Dallas Fort Worth Club Fitter & Builder
The Highlands Performance Golf Center, Carrollton Texas 
Golf Digest Certified America’s 100 Best Club Fitter

Korean Hidden Technology autoFlex Driver shafts came to the US market several years ago. I saw one in 2021. They cause a sensation with a $790 price point. They were very light weight and started a trend for light weight driver shafts. Ultimately most US golfers were not ready for light weight shafts at that price point.
I met with Korean Hidden Technology at the PGA 2025 merchandise show and shot an interview in their booth. They followed up with a shipment of review samples of every SKU they make. This is the first Korean Hidden Technology shaft that was available in the US in 2021. I had access to a single shaft then unlike now that I have measured all the shafts available at https://autoflex.us/. It was no small task measuring the 100+ shafts they supplied. KHT makes driver, fairway and hybrid shafts in each model family. Some models also have matched iron shafts. This is unique. The autoFlex is available in 4 color choices. That added some confusion to sorting the review samples. You must ignore colors and focus on the model designation printed on the shafts.

To continue reading this section of the review, you must be registered at a higher level membership.
Russ

AutoPower Snipe Shaft Reviews

Korean Hidden Technology AutoPower Flex Driver / Fairway and Hybrid Shafts

By Russ Ryden, Fit2Score, A Dallas Fort Worth Club Fitter & Builder
The Highlands Performance Golf Center, Carrollton Texas 
Golf Digest Certified America’s 100 Best Club Fitter

Korean Hidden Technology AutoFlex Driver shafts came to the US market several years ago. I saw one in 2021. They cause a sensation with a $790 price point. They were very light weight and started a trend for light weight driver shafts. Ultimately the recreational US golfer was not ready for light weight shafts at that price point.
I met with Korean Hidden Technology at the PGA 2025 merchandise show and shot an interview in their booth. It is on the list of videos that need to be published. They followed up with a shipment of review samples of every SKU they make. This is the first of many reviews of the 100+ shafts that arrived. They have created heavier, stiffer shafts for the US market. And, in many models they offer matched driver, fairway and hybrid shafts.

To continue reading this section of the review, you must be registered at a higher level membership.
Russ