MOI Special Report

If swing weight measurement is to determine the weight of a golf club from its mass in respect to its balance point, then MOI measurement is to determine the centrifugal force in respect to its swing weight. Both of these when applying on a golf swing, it is simply reflected as a feeling of how much force does a club requires to be swung in respect to time within the swing motion.

How does this apply to golf swing?
In simple understanding, if I could match irons set according to MOI instead of SW, I could switch from iron to iron maintaining the same rhythm with the same swing force, where as in SW I have to adjust my rhythm accordingly.

MOI approach:
To accurate measure MOI in golf club, it requires expensive equipment like MOI machine
Yet, Dave Tutelman had done extensive research and provide the poor-man fitting method (reference 4) which I currently adopt. Below is where I begin the long struggle of clubs fitting process.

MOI Equation:

MOI = Lc2 * (H + S/3) + 10 * G			S is weight of the shaft	Lc is length of the club
			H weight of the head	G is grip weight

First attempt:
Used an ½ SW point per ½ inch method. Picked my favorite 7 iron, starting from C9.5 and progressively reduce ½ SW point to 3I and increase ½ SW point to PW.

Match 2: MP 32 + 1150GH + Golf Pride DD2
IRONS	T W	WH + WS	WH + WS + TW	W S (+Grip)	WS	L S	W H	W H + T W	MOI	MOI / 1000'S	Jeff's MOI	SW
3	6	400	406	162	112	38.75	238	244	422,940	423	141	C7.5
4	6	407	413	163	113	38.25	244	250	421,374	421	140	C8.0
5	5	413	418	163	113	37.75	250	255	417,568	418	139	C8.5
6	6	420	426	162	112	37.25	258	264	418,619	419	139	C9.0
7	4	428	432	163	113	36.75	265	269	414,673	415	138	C9.5
8	6	435	441	161	111	36.25	274	280	417,058	417	139	D0.0
9	6	444	450	163	113	35.75	281	287	415,444	415	138	D0.5
P	6	453	459	162	112	35.50	291	297	421,844	422	140	D1.0

Result: MOI is random

Second attempt:
Used more precise measurement: +/- ½ SW point and 1.35 SW point per inch (0.675 SW per ½ inch), progressively increasing SW from 3I to PW.

Match 4A: MP32 + 1150GH + Golf Pride DD2
IRONS	Actual TW	WH + WS	WH + WS + TW	W S (+Grip)	WS	L S	W H	W H + T W	MOI	MOI / 1000'S	Measured SW
3	4	400	404	162	112	38.75	238	242	419,936	420	7.5
4	5	407	412	163	113	38.25	244	249	419,911	420	8.0
5	7	413	420	163	113	37.75	250	257	420,418	420	9.0
6	7	420	427	162	112	37.25	258	265	420,006	420	9.5
7	6	428	434	162	112	36.75	266	272	418,274	418	10.5
8	8	435	443	161	111	36.25	274	282	419,686	420	10.5
9	9	443	452	162	112	35.75	281	290	418,852	419	11.0
P	8	453	461	162	112	35.50	291	299	424,364	424	11.5

Result: MOI is more uniformly distributed yet it is still unsatisfactory

Third attempt:
Manually adjust tip weight and computationally match MOI at 420 range

Match 4B: MP32 + 1150GH + Golf Pride DD2
IRONS	Round TW	WH + WS	WH + WS + TW	W S (+Grip)	WS	L S	W H	W H + T W	MOI	MOI / 1000'S	Ref Target SW	Actual SW	Adjusted SW
3	6	400	406	162	112	38.75	238	244	422,940	423	7.475	9.0	8.0
4	7	407	414	163	113	38.25	244	251	422,837	423	8.15	8.5	8.5
5	9	413	422	163	113	37.75	250	259	423,269	423	8.825	10.5	10.0
6	9	420	429	162	112	37.25	258	267	422,782	423	9.5	10.0	10.5
7	8	429	437	162	112	36.75	266	275	422,326	422	10.175	11.5	11.5
8	10	435	445	161	111	36.25	274	284	422,314	422	10.85	11.5	12.0
9	12	443	455	162	112	35.75	281	293	422,687	423	11.525	11.5	12.5
P	10	453	463	162	112	35.50	291	301	426,885	427	12.2	2.5	12.5

Result: MOI range is tighter while PW is specifically left with high MOI. I figure SW is more important for wedges due to partial and finesse swing for short game. Overall SW is bumped another 1 ~ 2 point from assembly.

Final assembled attempt:

Mizuno MP32 + Nippon Shaft 1150 GH + DD2
IRONS	Round TW	WH + WS + Grip	WH + WS + TW	W S (+Grip)	WS	L S	W H	W H + T W	MOI	MOI / 1000s	Ref Target SW	Actual SW	Adjusted SW	Raw SW
3	6	400	406	162	112	38.75	238	244	422,940	423	7.475	9.0	8.0	5.0
4	7	407	414	163	113	38.25	244	251	422,837	423	8.150	8.5	8.5	5.0
5	9	413	422	163	113	37.75	250	259	423,269	423	8.825	10.5	10.0	5.5
6	9	420	429	162	112	37.25	258	267	422,782	423	9.500	10.0	10.5	6.0
7	8	429	437	162	112	36.75	266	275	422,326	422	10.175	11.5	11.5	7.5
8	10	435	445	161	111	36.25	274	284	422,314	422	10.850	11.5	12.0	7.0
9	11	443	455	162	112	35.75	281	292	421,409	423	11.525	11.5	12.0	6.5
P	10	453	463	162	112	35.50	291	301	426,885	427	12.200	12.5	12.5	7.5

First Test Impression:

number of balls tested: 180 balls location: Lake Success Driving Range
Overall the “new” irons sets are lighter than my previous set by average of 8 grams in static weight. How much is 8g in static weight differs? Not much since my swing weight is kept at the same range. However, it is a lot easier for me to switch from club to another club, especially noticeable with 3I. I have tried on randomly chosen iron from one club to the other and I could not feel any difference in swinging force. Using the same rhythm to swing each club, the feel is tremendously rewarding, even though PW is felt much heavier than 3I in static weight, they are comparable similar in motion. There is virtually not much change in trajectory, height and distance, but I feel it is much easier to produce desired shot with each club under MOI matching. This set of iron is suddenly more forgiving than ever.

Equipment used:
Mizuno MP32 3I ~ PW + Nippon shaft 1150GH Tour stiff + Golf Pride DD2
Digital scale (Accuracy +/- 1g)
Golfsmith shaft puller + swing weight scale (Precision 0.5 SW point) + golf clubs making essentials
total cost: $126 for 9 Nippon Shafts + $4.56 DD2 grip each

References:

1. Tom Wishon on MOI:
http://www.wishongolf.com/moi.php

2. Definition of Moment of Inertia:
http://en.wikipedia.org/wiki/Moment_of_inertia

3. Why your golf club is obsolete:
http://www.calgolftech.com/whats_new/driver57.html

4. Dave T’s club design notes:
http://www.tutelman.com/golf/design/swingwt4.php?ref=#measure_moi

The moment of feel

The best feeling of hitting a golf ball is when the shaft is felt to be “unloading” prior to the impact. This is especially true when hitting with a driver.

The feeling of shaft-unloading, in simple terms, is pure transformation from shaft bending and unbending. During backswing, shaft starts bending uniformly throughout the swing, at the top of backswing, bending pause and goes the other direction when golfer’s arms start to come down. In a proper swing movement, where hands are leading the shaft, it is felt that there is a flex in shaft following all the way through the downswing until when the shaft is “released” prior to the impact, when the shaft unbends itself and release the energy from bent to straight formation, the energy is “released and hopefully transform onto the ball.

From a spectator’s point of view, during the moment of impact, the shaft should seem like it is chasing or closing to the golfer’s hand position due to this energy-release transformation. In a hand leading swing, from spectator’s point of view, the bending in shaft should happen all the way starting from top of backswing to anywhere prior to ball impact.

However,

If hands are still leading the shaft after impact, this means shaft is not properly released, this could be caused by bad swing, shaft too soft and bad timing, this delayed in time will very easy cause an open clubface and force a pull/push slice. (This is where hands supination is important)

If hands never lead throughout the swing, this fact wipes away all the joy in a golf swing as golfer would not have felt the unloading in shaft. This could be caused by bad swing, shaft too stiff or hands-only swing. This advance in timing will usually lead to close clubface and hooking in ball flights.

Problem with lighter shafts

Lighter shafts will decrease club swingweight, in order to maintain the desired swingweight, usually there are two approach to achieve this:

1. Increase shaft length

Head weight 195g → 44 inch → C4 → 256cpm
　 Head weight 195g → 45 inch → D0 → 250cpm
　 Head weight 195g → 46 inch → D6 → 244cpm
When club length becomes longer, balance point move closer to butt end, shaft frequency becomes lower indicating shaft becomes softer.
*with approximate 1 inch change in balance point, there is 6 points change in frequency per minute

2. Increase head weight

　　45 inches → head weight 193.5g → C9 → 251cpm
　　45 inches → head weight 195.0g → D0 → 250cpm
　　45 inches → head weight 196.5g → D1 → 249cpm
When club head weight becomes heavier, balance point move further away from butt end, however frequency becomes softer and shaft becomes softer
*with approximate 1.5g change in head weight, there is 1 point change in frequency per minute

- in reference to http://www7.ocn.ne.jp/~golcom/

It is easier to store energy with lighter shafts as it is easier to swing smoother and faster, this fact is usually mistaken as softer when compare to heavier shaft, providing they have similar flex rating. Yet, the “soft” feeling is only enhanced when trying to match the club back to its original swingweight. In order to maintain a light shaft with D2 SW and stiff flex by making it slightly longer, it is wise to use extra stiff to begin with as shaft’s CPM could drop one full step in flex rating when shaft is 1 inch longer.

On the other hand, by shortening the shaft length and increase the head weight, the balance point will move closer to club head and it will enhance the result of “Soft-tip” where ball is launched higher than desired.

Poor man shafting theory

1. Torque is the most underrated specification in shafts except manufacturers’ use.
2. For a softer feel, choose same flexibility but higher torque shaft. Lower torque by definition is to prevent the head from twisting along the shaft, yet a better feel club with higher torque will help improve synchronized rhythm and swing to square the head at impact.
3. To improve feel of control, get the lowest torque available for regular flex shaft. The “resistance-of-twisting” provides you the “square” head at all time.
4. We tend to swing with more force using heavier clubs, smoother using lighter clubs. Golfers that advise to use heavier club to stabilize swing movement are blowing horns. Opposite in Putters.
5. Shaft weight should be proportional to golfers’ weight, the heavier you are, the heavier the club in static weight should be. This does not apply to Swingweight. Test swing freely from 55g shafts to 95g shafts, the one that you could exert more force without losing feet balance would be the chosen one, pick the shaft with 5 ~ 10g off from the chosen one.
6. Golfers who like to feel the shaft “kick” usually prefer lighter swing weight, on the opposite, golfers who like extra stiff shafts opt for heavier swing weight.
7. Head size has nothing to do with distance, so is shaft flex.

Putting Breaks

Say I could putt straight, I could determine the rolling speed, say I could repetitively execute the same putting stroke, say I am willing to spend hours and hours to practice putting, but how could I determine the slope on the green? How am I able to “practice” how to read breaks? Determining slope or break on the green is more a personal intuition and experience from the combined judgments from rolling speed, grains, putting strokes and etc.

First, putt straight directly aiming to the pole / hole with the correct speed, if there is a right-to-left break, the ball will break away to the left.

Second, virtually measure how much the break is by determining the distance from the ball that comes to a stop to the hole. This distance should be how much the break is, thus on the next putt, I should aim to the right with such measured distance

Third, putt by aiming to the right with the distance measured using the same stroke from the first putt. Fine tuned the stroke or breaks if the ball does not drop into the hole

Fourth, read the green again by squatting down, from 20 feet away or from the other side of the hole, “train” the brain to recognize the break and slope-reading.

Wondering if you know . . .

1. There are only three parts to the golf club – the head, the shaft, and the grip – it isn’t a complex equipment, but if you have the wrong head, shaft or grip the equipment will be near impossible for you to play the game.
2. Your driver swing speed will determine you driver loft and shaft flex.
3. Your 5 iron swing speed will determine the flex of the shafts in your iron.
4. Every golfer looking at a driver in a golf store looks at the head first and then holds the club by the grip and waggles the club. However, he or she rarely looks at the most important part – the shaft. (Check it our next time you are in a golf store.)
5. The correct driver for you is not the one you can hit the farthest. It is the one you can hit with consistency farthest.
6. Loft is your friend.
7. The shaft is the engine of the club. Arguably, it is 55% importance of the club, the head is 40% and the grip 5%. Why doesn’t anyone look more at the shaft?
8. The average length of a driver on the PGA tour is 44.5”.
9. The golf industry has no standard flexes. What is a stiff flex for one shaft manufacturer is can be a regular flex for another.
10. Most – not all, clubheads are made in a few foundries in mainland China. So what is the difference between Titleist and TaylorMade? It is probably manufactured in different province.
11. Have not seen any Original Equipment Maker (OEM) that makes their own shafts. They are jobbed out to shaft companies, sometimes multiple companies for the same shaft.
12. The golf industry has no standard length for golf clubs. A poor man’s custom set of clubs includes a set of clubs where all the clubs are cut ½” apart, the grips are all the same, the swing weight is the same through out the irons and through out the woods, and the loft and lie are correct.
13. Lie is one of the most important physical attributes of your irons. If the lie is wrong, that is either flat or upright; your shots will go left or right, more in the wedges and less in the long irons. Why doesn’t anyone look more at the lie angle?
14. Do you know that a 10.5° driver is only 10.5° at the “sweet spot?” It can be as much as 13° at the top of the face and 9° at the bottom – that is because of the roundness of the head from top to bottom. The horizontal “roundness” of a club, from side to side, is called bulge. If you want to hit your 10.5° driver at 10.5°, you better hit it at the sweet spot.
15. Did you know the “sweet spot” is exactly a spot on the face of a club? It is not an “area”. You cannot increase the size of the “sweet spot.” You can increase the hitting area – but not the sweet spot.
16. Nearly all clubs heads are made with plus or minus 1 degree in loft and that very same driver compare to number #20 may really be a 10.5° or 12.5° club. Nearly all OEM irons are made with plus or minus 1 SW difference, 3 iron could be a D1 while PW is D3.
    

-- in reference to California Custom Clubs

New Club to the bag?

I am hooked by the new Miura Giken MD390...










Looking at my bag now...

• Driver: Nakashima NP-1 + Fujikura Speeder 757 = $300 + $250 = $550
• 3 Wood: Mizuno MP-001 = $299
• Utility: TaylorMade Rescue Mid + Banzai 83 = $180 + $50 = $230
• 3 ~ P Iron: Mizuno MP-32 + Dynamic Gold S300 = $850
• Wedges: Mizuno MPR 54 + MPR 60 = $99 + $99 = $198
• Putter: Gauge Design GAA = $250
  

Total Retail Cost: $2377

Ebay worth value: maybe 40% of retail?
Golf, can drive me nuts, really.

Golf and Photography

One of my talented colleagues, who is a good amateur photographer that I admire, told me this tips once...
"How do you take a good picture in the dark without tripod?"
"The answer is simple, breathe out slowly before pressing the shuttle, that is the time when the body is most quiet and relaxed."

Most quiet and relax.... Most the time we pull an erratic swing in golf is due to our tempo is missed or off. In other words, either we hold our breath too long or we introduce too much "force" to generate an erratic powerful swing, rather than the smooth and relaxed swing that is desired.

I tried this method on golf course the other day, breathe out slowly before I initialized my driving swing, the result is rather impressive, I managed to keep 12 drives out of 15 trials on the fairway.

Thanks to my colleague's expertise in photography and generosity to share, this is the best tips I ever received, through the art of perspective in colors...

Golf and Stocks

Always feel unjustified when golfers with the lousy swing mechanics play a better score than I do.

While I am struggling to get my shoulder turn correctly, making sure my spine angle is maintained, stable footwork, strong grip... These guys with hands way outside the left foot at address, bouncing vertically up on downswings, hands dominant rotation end up with a score unjustifiably impressive.

It is then I realize a similarity between golf and stock investing. Stocks in general go bullish over the time. A guy who is ignorant to stocks, providing that he is not too greedy and just simply purchase some fundamental strong stocks, most likely he will earn a good return over the time.

A golf swing, no matter how is it being produced, generates enough force to push the ball forward. With less distance and less airborne time from these poor swings, it actually reduces the chance of generating errors on course. It is the same that as if the same person invest in stocks, without rapidly getting in and out of market, the chance of him being dragged down by directional movements in the market is greatly reduced.

It it golfers that understand the half of it yet not skillful enough in consistency that will lead huge problems onto the golf course.

To improve and play to the full potential, full knowledge and capable of applying it on course is the ultimate challenge. Yet, knowing half the knowledge and incapable of applying it is worst.