Wednesday, November 2, 2011

The “New” SuperLite Shaft Trend – Who’s it For?

By Tom Wishon:

One of the advantages to getting “longer in the tooth” in any area of interest is it gives you the opportunity to separate the “been there done that” from the things that truly are new and different. One of the latest “rages” in the golf equipment industry is the current trend among some of the companies to offer “superlite” drivers – drivers made with a graphite shaft that weighs less than 50 grams to allow the total weight of the driver to be less than 300 grams (@10.5 oz).

The marketing concept behind these very light weight drivers is simple – the lighter weight driver can be swung with the same effort to achieve a higher swing speed, from which comes more distance. This concept of go lighter to swing faster is definitely not a new direction in club design. Veteran clubmakers may remember the short lived fad started by the Dave Pelz Featherlite clubs of the 1980s with their B-8 to C-O swingweights, as well as the mid-90s era of superlight weight drivers whose sub-300 gram total weight was made possible through the design of light graphite shafts with a huge butt diameter that required a very light weight grip.

Today’s trip down superlite memory lane is fueled by the design of graphite shafts which weigh less than 50 grams yet can still be made with a flex and bend profile to meet the needs of the most powerful swingers in the game.

To give credit where credit is due, it is a remarkable step forward in graphite shaft design to be able to make a 45 gram shaft with a flex and bend profile design that could fit a golfer with a 110mph clubhead speed and aggressive swing characteristics. Shaft makers have achieved this by using expensive high modulus composite materials in a thin wall shaft construction. Up until a few years ago, a 50 gram graphite shaft was chiefly for easy swinging golfers with swing speeds under 90mph.

But now that we do have access to superlight weight shafts in any variety of stiffness design, the question that has to be answered is “who are these shafts and resulting super light weight drivers for?” if you buy into the big companies’ marketing, they’re for EVERY golfer. But if you buy into the concept of professional clubfitting, determining what golfers are best matched into such a light weight design is a matter of probing the golfers’ strength, the force they apply when starting the downswing (transition force), and their downswing aggressiveness.

Typically, the stronger the golfer, the shorter the backswing and more forceful the transition, and the more aggressive the downswing, the heavier the shaft and total weight of the club should be to ensure the golfer can maintain a consistent, repeating swing tempo that allows the highest percentage of on center hits.

However, there is one “fudge factor” in this which will allow some golfers with stronger, more aggressive move at the ball to potentially use a very light weight shaft to gain clubhead speed while retaining their proper sense of swing tempo and timing – and that is by partnering the very light shaft with a higher than normal swingweight or more pronounced headweight feel in the club. What you don’t want to do is give an aggressive swinging golfer a very light shaft with a low swingweight.

By cranking the swingweight higher than normal, this can offset the strong aggressive swinging golfer’s tendency to get too quick with their tempo when using a club with a very light weight shaft.

On the other hand, the biggest population that can gain from a sub-300 gram driver total weight are golfers of average to lower strength who swing more smoothly with a less aggressive downswing move at the ball. But even with these golfers, you still have to experiment with the headweight to get to a point that each golfer can feel the presence of the head enough during the swing so as to maintain a consistent swing tempo.

Until next time, best wishes in this great game,


Tuesday, November 1, 2011

Can you pleasew explain the terms "bend point" or "flex point" in regards to shafts?

Bend Point/Flex Point are terms from the "old days" which we really wish would just die and go away, never to be seen or heard of again. They evolved from a very old mechanical test done on shafts in the 1950s which had absolutely no relevance to how a shaft actually bends during a swing. The old bend point test involved fixturing a shaft so you could apply a pushing force inward from both ends of the shaft. The shaft bowed in response to this and the highest point of deflection was considered the bend point. Problem is that there is never a time during the swing in which a force is transmitted up the shaft form the tip and down the shaft from the butt. So the test and term is not relevant at all and needs to be discarded completely.

Then the industry moved to doing their bend point test by hanging a weight from the tip end (normal deflection test) and noting the point of maximum deviation from a straight line drawn from the tip to the butt. While this form of bending of the shaft was more relevant, the problem here is that if you do this test on every shaft you'll find the difference between the highest and lowest bend point is less than 2inches.

What we have instead are different bend profiles, or rather, differences in the distribution of stiffness over the full length of a shaft. This gives rise to generic terms like "tip stiff", "tip flexible", "butt stiff", "butt flexible" and so on. As generic terms, these too are not worthwhile because they are not specific enough to allow anyone to use them to compare shafts accurately from a fitting standpoint.

Which moves us into the graphs that are the key element for shaft comparison in the Bend Profile software where over 1200 shafts have been tested all along the length of the shaft every 5 inches. Something like this is FAR more relevant for comparing the stiffness design of shafts so as to know more about how the shafts differ in stiffness design, WHERE they differ on the shaft and by HOW MUCH.