| Design advances in woods have everybody talking. | | | | center of gravity (COG) or improve moment of inertia |
| From larger clubheads to the use of exotic materials, | | | | (MOI). |
| today's woods are not only designed better, they're | | | | Re-positioning the COG, as I've explained in my golf |
| also manufactured better. Add to these changes the | | | | tips, creates a more forgiving iron, with a larger sweet |
| advances made in shaft technology, and you have | | | | spot along the blade. Thus, a mis-hit with an iron whose |
| well-crafted metal woods engineered specifically to | | | | COG has been re-distributed is more likely to stay on |
| help you chop strokes off your golf handicap. | | | | target than a similar shot with an iron whose COG has |
| But advances in iron design are helping players as well. | | | | not been redistributed. Why? Because a redistributed |
| Golfers don't talk as much about these advances as | | | | iron twists less in a player's hand when the ball is |
| they do about those in woods, but they're just as | | | | mis-hit. The ball is also likely to travel farther on a |
| significant for improving your game. Iron advances, like | | | | mis-hit as well. |
| those made in woods, help you hit the ball longer and | | | | MOI is a property of physics that indicates the relative |
| straighter, and shave strokes from your golf handicap. | | | | difference in how easy or difficult it will be to set any |
| Let's take a closer look as some of these design | | | | object in motion about a defined axis of rotation. The |
| advances. | | | | higher the MOI of an object, the more force will have |
| Perimeter Weighting and Investment Casting | | | | to be applied to set that object in a rotational motion. |
| The revolution began forty years ago when Karsten | | | | Conversely, the lower the MOI, the less force needed |
| Solheim turned traditional iron design on its head by | | | | to make the object rotate about an axis. |
| introducing the concepts of perimeter weighting and | | | | Shaft Lean and Swingweight |
| investment cast manufacturing. Since then the | | | | Shaft lean is another new design concept that has |
| advances have continued apace. | | | | found its way into club design. Shaft lean is the angle |
| Perimeter weighting (PW) creates a large sweet spot | | | | at which the club must be delivered to the ball at |
| on the club. PW repositions the weight of the clubhead | | | | impact to create optimal pressure. Keep in mind that a |
| around the perimeter of the clubface instead of at its | | | | ball compresses when hit, which causes it to spring off |
| center. If a player always hit the ball dead center, he or | | | | the face at maximum velocity, which leads to |
| she would want a small sweet spot and no perimeter | | | | maximum distance. A forward-leaning shaft at impact, |
| weighting. That way the club would have as much | | | | particularly when hitting the short- and mid irons is |
| physical mass directly behind the impact point as | | | | critical to solid ball striking. |
| possible. However, if the player is off even a millimeter, | | | | Swing weight is also a key iron design feature that |
| his or her shot goes astray. By perimeter weighting | | | | affects performance. In non-technical terms, |
| golf clubs, manufacturers' create maximum | | | | swingweight is a measure of how the weight of the |
| forgiveness in the club. | | | | club feels when it's swung. Why is it important? If your |
| Investment casting is another key advancement in iron | | | | clubs do not match in swingweight, they may not all |
| production. Many manufacturers produce irons by | | | | feel the same to you during your swing. That slight |
| pouring molten metal in a pre-shaped cast. Cast irons | | | | change in feel could affect your performance with |
| provide the user with less feel, but are less difficult to | | | | those clubs. |
| hit consistently, and are therefore better suite for | | | | Philosophy and Intent Remain Key |
| players with high golf handicaps. Forged irons have a | | | | The introduction of concepts in club design, like |
| softer feel and are less forgiving to a user, but they | | | | swingweight and perimeter weighting, is not new in |
| cause the ball to turn more off line when mis-hit. | | | | itself. Club manufacturers have always sought new |
| Thinner Designs | | | | ways to improve an iron's performance. What's new is |
| Solheim's advances were followed by the introduction | | | | their approach. They are now trying to think of ways |
| of new materials, like scandium alloys, and of improved | | | | to improve one area of the club while keeping the |
| manufacturing techniques, like computer-milled faces, in | | | | other areas consistent. |
| iron design. These advances also took iron design and | | | | What's this mean for you? It means that you must |
| construction in new directions. | | | | decide which design ideas are worthwhile and which |
| Club engineers were gaining a better understanding of | | | | are just marketing hype. Next time you buy irons, don't |
| how each characteristic of a clubhead, like moment of | | | | just buy something that's on sale. Study the philosophy |
| inertia (MOI) and center of gravity), impacts club | | | | behind the model's design and construction and what |
| performance, and were beginning to take advantage | | | | the manufacturer is trying to achieve with the club. If |
| of this knowledge. Today's clubfaces, for example, are | | | | you do that, you'll get your money's worth and you'll |
| thinner than their predecessors. Thin design frees up | | | | get a set of irons that will help you lower your golf |
| more mass that designers can redistribute to lower the | | | | handicap. |