Golf Talk

Square Drivers, Part 2

As stated in Part 1, MOI is the point (or “moment”) at which an object resists rotation, so changing the mass around this point changes the MOI. The composite drivers such as the FT3, Cobra Comp and Cleveland Comp are all examples of using different materials, e.g., carbon instead of titanium, to shift weight away from the center of gravity and, thus, increase the MOI. (The forerunner of this trend was the Yonex carbon headed ADX drivers from the mid-90s). Nike has gone a step further in increasing the MOI of the driver head by squaring the shape.

Tom Wishon talks about the transition in putter head shapes since the Odyssey 2-Ball was introduced. The triangle or horseshoe shape that characterizes many of the new putters is an example of increasing the putter head’s MOI, resulting in less twisting of the putter head and more accurate putting. This same concept can be applied to driver heads.

As I understand it, the MOI of a golf club can be measured from heel to toe (Izz); from sole to crown (Ixx); in the droop direction (slope of the crown to the toe, Iyy); and from around the hosel (Ihh). In any of these measures, we are talking about distributing mass so as to increase the clubhead’s inertia, or resistance to twisting. The Izz measure, heel to toe, cannot exceed the new USGA limit of 5900 g-cm2 (which is an “inertial load” metric, not a standard measure of mass).

Nike talks about “a platform of geometry.” I’m not sure what role geometry plays in the physics of MOI, but I think I understand why squaring the clubhead might increase MOI, which is all that matters anyway.

Nike asserts that the square shape allows for optimum placement of the inertial load as measured from heel to toe. The new Sumo2 driver has a square shape, a carbon crown and titanium body and face. The square shape allows for distribution of mass in the corners, mass that was removed from the crown by substituting carbon for titanium.

The Sumo2 has an MOI of 5300, which reduces the yardage loss on mis-hits and may result in longer, straighter drives on good hits. I get the impression that the first outcome may be the more important of the two, given how often mis-hits occur over good drives. The high MOI makes the club more stable at impact, so if you hit if off center, you won’t lose distance. These mis-hits should also be straighter, resulting in fewer out of bounds shots.

Tom Wishon points out that for the “MOI to deliver more forgiveness for an off center hit of a distance increase of 5 yards or more, the MOI has to be increased by 1000 g-cm2 or more, [assuming that the driver’s specs fit the golfer’s swing]. He claims there are other drivers on the market that have an MOI in the area of 4500 to 5000 g-cm2, which, if matched to the golfer re: shaft, loft, face angle, etc., are likely to perform as well on a mis-hit drive as the new Sumo2.

I don't agree with Wishon on this point, if only because 1000 g-cm2 is a huge percent of the total. Why would Nike trumpet the superiority of the Sumo2 with an MOI of 5300 when the original Sasquatch had an MOI of 4650, exactly in the area Wishon references?

The 2Ball putter made a big difference in the way putters were designed and marketed. As I wrote earlier, Charlie thought they were too expensive, yet we couldn't keep them in stock when they came out. If the new Sumo2 performs like the 2Ball putter, all the manufacturers will have to come up with a version of one, and many golfers will not care how much money they cost.

Cobra—Fit To Speed

Submitted by Eileen on Fri, 10/27/2006 - 23:47

I attended the Cobra Fit To Speed webinar (seminar on the web) earlier this week. Cobra has launched a Fit-To-Speed fitting cart that includes woods, hybrids and irons in different shaft flexes, and some of the irons have different lengths and lie angles. The cart has nowhere near as many clubs in it as the Ping fitting cart, but the concept is different.

Cobra’s whole emphasis is on ball speed; something that can be measured using a stand alone speed monitor that comes with the fitting cart. The speed monitor measures and reports ball speed, launch angle, estimated club head speed and distance. (Our Full Swing Golf simulator does most of this, too, but the Cobra Speed Monitor will be a useful verification of these metrics).

Once the golfer’s ball speed and related swing specs are determined the Fit to Speed Wheel is used to see what Cobra driver and iron set composition are best suited for this golfer. The iron set is likely to include a hybrid, in this case a Cobra Baffler.

After the driver and iron models are selected the length and lie angles are verified using face and sole tape. Cobra recommends face tape to verify club length rather than a wrist to floor measure. (I like the idea of using face tape to verify that a longer club is actually producing a more centered hit for people who need longer irons.)

The Fit-To-Speed Wheels are set up to reveal best iron set composition and wedge preferences, as well as recommended iron model. The Wheel also has the driver recommendation linked to the ball speed associated with the iron specs. (I’m not sure if the wheel shows where launch angle and distance factor into the driver selection, but I’m still learning how to read it.)

Cobra is coming out with a new Baffler and a Baffler Pro for the “extreme speed” player. There are three new iron models aimed at the “Core and Avid Golfer Segments,” which represent about half the golfer market. Since about 20% of this group is made up of “extreme speed” golfers Cobra has the Carbon CB iron and the Baffler Pro for them.

The purpose of this new approach is the make fitting golf clubs more interesting and appealing to a wider audience—“give consumers a reason to ask to be fit.” This system does look interesting and if it results in more sales, I’m all for it (even if it takes 45 minutes to do—something I generally try to avoid).

Rangefinders: Are They Legal?

Submitted by Eileen on Sun, 05/14/2006 - 09:00

There’s been a flurry of interest in rangefinders and GPS devices that many golfers are using to determine distances. We were carrying the Bushnell Pinseeker Rangefinder and a few years ago we carried the SkyGolf SkyCaddie, which at the time was a Palm Vx with special software. The Palm version of the Sky Caddie was pricey and too complicated. It was also so new that most people couldn’t see how they’d use it.

Today, customers are asking about the Bushnell and continue to gasp at the price (over $400). Charlie has warned them this device may not be legal if it can provide slope measures, which is probably the primary reason to buy this model over something cheaper.

The confusion over the legality of the Pinseeker is absurd. It really does matter where you play and who’s running the event. After reading 1000 words on the subject in GolfWeek and talking to the pro at the local municipal course, if someone asks me if the Pinseeker is legal all I can say is “maybe—but you better ask before you play.”

Syndicate content