Dynamic Gold AMT Iron Shafts

By Russ Ryden and Mark Maness

Russ is the owner of Fit2Score, Dallas Fort Worth, Texas
A Golf Digest America’s 100 Best Clubfitter 

AMT stands for Ascending Mass Technology. It is not a new concept. Ping has had ascending weight shafts for many years. Nippon 999’s were ascending. Aerotech Players Spec were ascending. If you are not a club maker you probably have not been exposed to the concept. Briefly, there are primarily two kinds of shafts; constant weight tapers and parallel’s. Constant weight tapers are made to length in the factory and the shafts in the set are all the same weight even though they are different lengths. Parallels are made to one length in the factory. The club maker cuts them to the length needed for the club he is building. As they are cut shorter they weigh less. The shafts in a set are lighter in the short irons than in the long irons.  I wrote an article about this some years ago in the technical stuff section of this site; Constant Weight vs Parallel Iron Shafts.

Iron heads get heavier as the the numbers get higher. The 4 iron head is heavier than the 3 iron, the 5 iron is heavier than the 4 iron and so on down to the gap wedge. In sets made of parallel shafts, the shafts get lighter while the head gets heavier. In sets made from constant weight shafts, the shafts are the same weight while the heads get heavier. In ASCENDING WEIGHT sets, the shafts get heavier as the heads get heavier. This has always been an attraction the club builders that create MOI, Moment of Inertia, matched sets.

The term MOI is most often used when discussing heads. It is the force required to spin a golf head. The golf club rotates around its handle during the golf swing and it too has an MOI. It is typically measured at the butt end of the club. The club is fixed at a pivot point at the top center of the grip and swung like a pendulum while the rate of rotation is measured.

MOI matching is an alternative to Swing Weigh matching in the building of a set of irons. Ascending weigh shafts make building MOI matched sets easier. I have seen some Ping sets with ascending weight shafts come close to both a swing weight match AND an MOI match. That is the attraction of Ascending Weight shafts to the custom builder.

Because this is such a unique set of iron shafts, this review is going to contain more information than I usually present. Lets start with a look at the weights of the uncut shafts in the sets. As you can see, they clearly get heavier as they get shorter. More so than any ascending weight set I have seen to date. That being the case I did full documentation on a set or irons built with the Tour Issue X100s.

This is very detailed information from the Fit2Score building worksheet I use to prepare and document custom built sets. This set is 1/2 inch long built for a former PGA Tour player that has been accustomed to swing weights above 6 because of the extra length he uses. As you can see, the set has slightly ascending swing weights with nearly flat MOI values. I will go back into that P wedge and add some weight to align it with the rest of the set. On the initial build I wanted to see how the set built and played without modifying head weights.

Mark Maness, Director of Instruction, The Golf Center at the Highlands has been testing this set of irons built with the Tour Issue X100 AMT shafts. His comments: I have played KBS Tour shafts the last 3+ years and enjoy them.  Before that, flighted rifle 6.0’s and various Dynamic Gold flexes. Testing the Dynamic Gold AMT X100 was a new experience. I’ve never had a set of clubs that were MOI weighted and now I wish I had. Over the last several years, I’m now 55, I’ve found it increasingly difficult to hit long irons to my desired distances without doctoring the clubs or “cheating” to an iron hybrid like the Titleist TMB (with an AMT shaft). As I hit the  AMT’s in my 714 MB Titleist’s the short irons felt familiar, a bit like my current KBS Tours and my old Dynamic Gold X100’s. The mid irons were a little lighter, but not a major difference. When I got to the 5 and 4-irons things changed.  I felt at ease swinging them and getting easy distance.  Over the last few years I felt like I had to work my long irons for distance. That was not the case with the Dynamic Gold AMT’s.  I’m looking forward to playing with them and really coming around on the notion of MOI weighting iron sets.

Let’s take a closer look at the profiles of the Dynamic Golf Ascending Mass Technology shafts. Like all Dynamic shafts from True Temper, the profiles of the R, S and X sets are different. This is explained in detail in the article on the Dynamic Gold. The tip length effect on the profiles of the different flex’s is apparent in these charts.  The flex profiles within the sets are very consistent despite the weight changes within the sets. There is a very small weight change between the sets, but as with all True Temper Dynamic designs, the different flex’s represent different flighting patterns. The R being a high launch, S mid launch and X low launch.

Comparing the AMT X100 to the standard X100 I see a small amount of what we traditionally call ‘flighting’ in the set. The stiffness gradient is larger. The longer iron shafts are softer in the AMT set than the standard X100’s. Fitting experience has shown that softer flex’s tend to launch higher for a reasonably skilled golfer. I can make subtle launch changes by hard stepping or soft stepping a set of shafts. The AMT not only makes it easier to create a MOI matched set, they also add progressive launch in the long irons. This is all good stuff if you find your Dynamic Gold long irons a challenge to launch as you age.

This is a great step forward in iron shaft technology. Keep it coming, True Temper, the club building community has waited a long time for a set of iron shafts like this!