Technical Papers by UST Mamiya

UST Mamiya Introduces Proforce V2 Iron Shafts

Constant-weight design equals better performance better players crave

As a top graphite golf shaft manufacturer, UST Mamiya is most noted for its plethora of tour proven wood shaft brands. Ask any avid golfer to name a couple of UST Mamiya-branded wood models, popular shaft brands such as Proforce V2 and IROD roll right off the tongue.

However, lost in the fray are numerous graphite iron shaft models introduced over the years. Ask the same question with regards to listing graphite iron shaft models, the probability of accurately naming just one model presents a lofty challenge to even the savviest of equipment gurus. Why is that? In years past, there has been a stigma with regards to graphite iron shafts performing less consistent than steel iron shafts. It is not for the lack of research and development or marketing resources, but demand for the product has not been there among elite touring professionals and mid-to-low handicap players. For the better player, precision shots are paramount, and graphite iron shafts – though they feel better and get the ball airborne with ease – have not been able to deliver that kind of consistent performance, until now.

Times are changing. Over the last several years, performance attributes for all graphite shafts have improved in two critical areas: design and manufacturing.

“The biggest improvement for UST Mamiya is the use of our CASA software system to predict how the shaft is going to perform before a prototype is ever produced,” said Robb Schikner, director of engineering design and technical sales for UST Mamiya. “We are able to streamline what is proven as a prototype into production more efficiently with exact certainty on model specifications.”

UST Mamiya’s manufacturing techniques and design principles have seen continuous improvements over the years offering tighter tolerances not only for graphite wood shafts, but graphite iron shafts, too. Moreover, the company claims tolerances remain the best in category with the average tolerance for premium brands +/- 3 range. That is important for clubfitters because they know exactly how each shaft will perform based on butt frequency, launch, flex, and weight.

Though tighter tolerances are important for UST Mamiya to continue its rich tradition in manufacturing high performance golf shafts, it is the constant-weight design feature that makes the all-new Proforce V2 Iron shafts special.

Constant weighting means each shaft in the set are the same weight. For example, the Proforce V2 Iron shafts are exactly 95 grams in the long irons, the mid irons and short irons. That offers players not only a consistent feel throughout the set, whether hitting a shot 125 yards or 195 yards, but also remarkably improved ball flight and most importantly the best distance control ever seen in a graphite iron shaft.

“When golfers test a unitized iron set against a constant weight iron set, they notice a more consistent feel from club to club in the constant weight set,” says Jamie Pipes, manager of product testing and field research for UST Mamiya. “They also get a more solid feel and penetrating ball flight in the short to mid irons. Distance control from a long and short aspect is a lot more precise.”

The occasional flier commonly associated with a normal unitized blank graphite iron shaft has been eliminated with the Proforce V2 Constant Weight Iron shaft. In the past, better players would experience a shot from the fairway, hit under normal conditions, where the ball jumps off the club face hotter resulting in a shot that flew further than expected. This is typically more noticeable on short-iron shots.

In a unitized iron set you have to trim from both the tip and butt end…as much as four inches off the tip end to make a nine iron or any wedge. Adding to that, you will need to trim it from the butt end to desired length. This is a good feature for club builders to frequency match a set, but by the time you tip and butt trim in the short irons, a 95-gram shaft will be lighter by 10 grams or so. The ball flight goes up and distance control becomes an issue because the short iron shafts – the scoring clubs – are noticeably lighter which can cause a difference in tempo, rhythm and club speed. This reduction in weight may cause some distance control issues with fliers on some shots and other shots coming up short (note: a flier is not the only problem with reducing the weight in short irons. The ball may come up short because the reduction in weight may not get enough mass into the shot or into the ball.

Pipes adds that in a constant weight set, each iron shaft is designed to a specific weight and length for each club in the set. Wedge shafts are purchased at 36 inches and 95 grams. Each iron up through the set increases in length by half inch but the weight remains constant at 95 grams. The engineers in a constant weight set can design each shaft to a specific frequency and match the set without having to trim from the tip end. Club builders can simply install the shafts and butt cut them to length. The short irons purchase length is 36 inches and weighs 95 grams so the weight is consistent for better ball flight and distance control.

The 95-gram weight platform in graphite seems to be one of the most popular and offers the best performance for a variety of golfers. Shickner tends to agree, “A 95-gram graphite iron shaft offers the great feel and vibration absorption characteristics for which graphite is commonly known without sacrificing distance control or loss of feeling the clubhead position throughout the swing sequence.”

Lastly, the Proforce V2 Iron shafts have a tremendous amount of feel. Our engineers were able to slightly reduce the hoop strength in the butt section to offer the golfer better feel, while the lower torque provides a stable platform in the tip section for better shot-shaping control.

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