Dear David,
Let me address cutting and SWINGWEIGHT first, then the place of swingweight in putting FEEL second.
SWINGWEIGHT
Here's a good working definition, from
http://swingweight.com:
"Swingweight: A club’s weight distribution around a fixed fulcrum point. The fulcrum point is typically 14” from the butt of the club. Swingweight is commonly referred to as the relationship between the weight of the grip end of the club and head end. It is measured in alpha-numeric units such as D-1, D-2, and so on with higher letter-number units indicating more weight in the head relative to the grip."
Jamie Fisher in Golf Tips Magazine (June 1998) has this to say about cutting down a putter:
"But be aware that for every inch you take off, you'll lose between six and seven swingweights, which can significantly affect the feel of the club. To counteract a weight change like this, you'll most likely need to add some lead tape to the putterhead to restore the proper feel. "
http://www.golftipsmag.com/content/pastissues/1998/june/putterfitting.html. From the point of view of physics, swingweight is really "torque." Imagine sticking an apple on the end of a two-foot long dowel rod and holding it at the other end in one hand. Now imagine the same apple stuck on the end of a ten-foot long dowel rod of the same wood and diameter and holding it at the other end -- it's a lot "heavier" torque at the end of the longer rod. But the closer you move your hands to the balance or fulcrum point along the rod, the less "heavy" the "torque" feels.
It is my understanding that pros like a putter swingweight in the vicinity of D2 and a pretty stiff shaft, but I'm sure there is a lot of individual variation. This seems a bit light to me. I would bet that Alan Strand at Dandy Golf has a very good handle on swingweight, since one of the key features of his putters is the energy in the shaft and how to "access" it. I'll have to ask him what he thinks and report back. I would think a swingweight closer to D5 is better, but I haven't experimented enough to know for sure. Ray Floyd is a pro golfer who invests a lot of care and attention to his shaft flex in the putter, but he uses a tallish putter and stands pretty upright at address, so his experience is a little odd. Assuming a D5 putter to start with at 35 inches, cutting it down to 30 inches would remove a ton of swingweight - 30+ points at 10 points per letter. That sounds like a move from D5 to A5! Very very light indeed.
However, swingweight is only one of several contributors to "FEEL" in putting, and there are some serious issues about what sort of FEEL is good anayway, so let me turn to the second part of my answer.
FEEL
The concept of "feel" is an extremely vague term in golf and means different things to different people, which allows people to be very sloppy and imprecise in their language. Haptic "feel" or what happens phsyiologically in the nerves of your hands is one definition of feel. Some golfers explore the differences in sensitivity of the palm versus the fingers, etc., and speak of "safecracking" and soaking the hands in warm water and losing "feel" after a session on the range with the driver. Others speak of feel more in terms of timing, and frankly I don't know why they call that "feel" at all. Engineers speak about the vibrations that travel up the shaft into the hands after impact. Sports psychologists speak about the association-building between feedback from kinesthetic sense of movement, the sound of impact, and the haptic sense of feel all combined and the "grooving" of stroke motion. Putter designers speak about materials and inserts, swingweight, shaft length and flex, vibrational frequency, sound frequency, and grip material and design. Physicists talk about putterhead mass, motion, impact, impulse, and roll.
From all this, "feel" may be a resulting combination of any or all of the following contributing factors, depending on your meaning of "feel" -- putterhead material, face insert, mass distribution in the putterhead, sound emitted from impact, type of ball used especially type of ball cover, air humidity affecting sound transmission, hosel connection, shaft design and length, grip material, your personal haptic sense, your sense of movement dynamics in your body, your grip form and pressure, your attention to any of these at a particular point in time, and other factors. It is also worth noting that so-called "feel" FEEDBACK only arrives AFTER impact, after the vibrations in the shaft and via the air as sound have had time to reach your sense organs and then your brain.
Since shaft length directly affects swingweight, what Jeff Jackson observes is pertinent here:
"Just as with woods and irons, the shaft of a putter plays a role. The shaft of a putter has a key effect on the feel of the club. Some of the older pencil-shafted putters, such as Spalding’s Cash-In, transmitted tremendous feel to a player’s hands. Some golfers, though, said these shafts were not stiff enough; they would actually flex during the stroke. If a golfer tends to like more feel or is a “handsy” type putter, he or she might want a softer shafted putter. On the other side of the coin, if a quick, “pop” type of stroke is used, it may be best to suggest a stiffer shaft. A note here, golfers may also want to experiment with shaft materials such as graphite or aluminum to see if these materials produce a feel that may be preferred. For the ultimate in putter matching, Royal Precision offers frequency matched Rifle putter shafts. As successful putting is quite dependent on feel, trying as many putters as possible may help make a golfer’s final selection the best one."
http://www.swingweight.com/putter_fitting2.htm
Let me posit my own sense of "feel" as useful to the golfer. To me, the function of the grip is to monitor the tempo of the stroke, and little else. Of course the grip pressure has to be firm enough to keep from dropping the putter or letting it slip downward during the stroke, to react to impact forces by disallowing any putterface twisting, and to let the brain know where the hands are being moved back and thru in the stroke and whether the hands are active and thus twisting the face or path. Basically, once the grip pressure is set, the hands are there for the purpose and with the expectation of feeling NOTHING CHANGE! Let me explain a bit.
If the putt stroke is started too quickly with any snatchiness, the grip ought to be light enough to allow the putter handle to waggle inside the palms and fingers from the snatching action. You can watch for snatchiness, or monitor your whole body, but the insides of your hands on the grip will tell you more, quicker, and better info than anything else if you take the putter away too quickly. So don't strangle the putter handle or you'll rob yourself of this monitoring "feel" DURING the stroke. By the same physics of starting and stopping the mass of the putterhead, the insides of the hands monitor the transition at the top of the backstroke, as the putter coasts to a stop and then gradually starts back down with nice gravity acceleration. Too abrupt here, and your hands FEEL CHANGE by the waggling or levering of the putter handle. Too fast coming down, and the handle presses against the left hand's finger tips and undersides and the right hand's palm, like a race car driver pushed back by speed into the seat. Again, the hands would FEEL CHANGE during the stroke. The "waggle" that one hopes not to feel is a side-to-side motion inside the hands.
As the putter moves back and then down, the fingers and especially the left thumb down the top of the grip monitors the handle to make sure the putterface is either being kept square or being returned successfully to square for impact. If the hands detect and twisting or active muscles here, that's a problem, so the hands are there to FEEL CHANGE in a troubled stroke or FEEL NO CHANGE in a good stroke. The thumb print is there in hopes of NOT FEELING any twisting of the handle.
As the hands are required by the Rules of Golf to be back a bit from the ball (minimum lie angle of 10 degrees off vertical), there is inevitably some "carrying" function in the grip, or lifting and holding the putter up to keep the sole from resting down on the turf. Going back and thru in a good stroke, you don't want the hands to wander closer or farther from the elbows during the motion, and this is really monitoring the elbows in the hopes of FEELING NO CHANGE, but you can also think about where the hands are during the stroke. In this sense, you are also monitoring the hands to FEEL NO CHANGE in altitude (although this is not exactly correct, in that there is inevitably some smiley-face shape to the trajectory of the hands arcing up going back and thru).
At impact, the hands of course react to the blow and absorb the vibrations to "feel" whether the impact was solid, and this helps when combined with the visual watching of what happens and hearing the tone of the impact, but it's too late to help this stroke and only helps on the next stroke if you diagnose whatever made a stroke go bad so you can fix or avoid the problem next time. Even so, too tight a grip and you diminish the feel of absorbing the blow. And at any rate, what is to be avoided is having the grip so light or loose that impact is allowed to twist the face out of square. This is part of the balancing of setting grip pressure to begin with. So, again, your hands at impact hope to FEEL NO CHANGE in the basic orientation of the putterface, although they absorb the vibrations of impact and the back hand feels more than the front hand.
AND what most golfers mean by "feel" is really "power control." I think the concept of "touch" is more appropriate here, but since both "touch" and "feel" are ridiculously vague and nearly devoid of functional content as commonly used, it's not surprising that golfers use the terms in utter confusion begetting more confusion. But let's think about what is powering the stroke. If you are a "handsy" putter, then your wrists joints alter during the stroke. If you are an "armsy" putter, your elbows alter in the stroke. If you are a "shouldery" putter, your armpits alter in the stroke. But if you are a "pendulumsy" putter, none of your joints alter during the stroke -- instead, your upper torso pivots above hips moving the two shoulders as a unit, taking the arms and hands with them in a "triangle" that keeps its shape at all times. For a pendulum stroke, the HANDS ARE DEAD, the ARMS ARE DEAD, and the SHOULDERS ARE DEAD too! Nothing going on there at all, other than the maintenance of a nice light tonic stability. The gut and lower back muscles power the stroke.
So, from my point of view, swingweight has a very limited functional role in the sort of "feel" I want to know about DURING the stroke. The value of swingweight for feel is in the levering or waggling potential of the instrument we call a putter. The greater the swingweight, the more potential "amplification" of any waggling of the handle inside my hands from bad physics movements of the putterhead. So too light a swingweight is bad in a sense, but only in this limited sense. Because I don't use feel to MOVE the putter, swingweight doesn't matter for that.
As to feel at impact, the mass of the putterhead is not reduced by cutting the shaft down, so the actual impact is pretty much the same. However, the translation of vibration up the shaft and the frequency of vibration is changed, making the impact "feel" less resonant and more plinky. So rebuilding swingweight would help with this.
However, as you rebuild swingweight by adding tape, you alter the mass of the putterhead, and this affects not only "feel" but also "touch" or distance control. I agree with you that different weight putters for different green speeds is not the best idea. And I favor heavier putterheads for all greens. But I do so mostly because a heavier putter promotes a slower tempo and impact. A slow impact by a heavy putter sends the ball farther than a slow impact by a light putter. So for any significant distance on a green, even a fast green, the heavier putter lets me have a slow tempo -- and that promotes accuracy in line and distance. You just don't want to add so much tape that the putterhead forces you into a SLOWER tempo than you have trained for. That really can throw off touch and distance control.
So, to sum it up: what is the putterhead mass and swingweight before cutting it down? Can you avoid all the problems by just gripping lower and ignoring the excess handle sticking above your hands? If you cut the putter shaft down and then add tape to rebuild swingweight because you're "handsy" or otherwise want to feel powering the stroke inside your grip as th handle is pressed against your back palm, watch that your tempo doesn't get too slow from the added weight. Since most putters start out with the putterhead too light anyway, cutting the shaft and then adding tape to the putterhead is probably going to change the tempo from too-fast to slower-better, so that's probably not a big concern. The trend today is toward heavier putterheads, though, so you have to be careful.
There are three other considerations. One is where do you add the tape. The second is about adding material inside the shaft. The third is just to note how adding weight to the handle works with vibrations.
The tendency of amateurs is to hit the ball too high on the putterface, while pros hit below the midline on the putterface using the bottom half of the face. Amateurs stub too many putts, and pros never or almost never do this. At any rate, pros get used to using the lower half of the face and this influences ball position and trajectory of putterhead into impact (ball forward of center, putterhead arcing slightly up at impact). Some manufacturers weight the putterhead high so the center of gravity tries to wrap around the top of the ball at impact for a mysthical "true roll." other manufacturers locate the center of gravity low on the putterhead so there is a bit more "launching" the ball from the stroke, thus promoting "true roll." I like the bottom-weighted putters, like the new Rossa, and feel that this weighting scheme removes an issue that top-weighted putters inject into my mind. I just like the sense of "sending" the ball off with the low part solidest, rather than trying to whack it down the line across the top quadrant of the ball. So -- if you add tape, I would suggest adding it low on the putterhead, probably on the back. You could add it on the sole, but this would require you to very carefully shape the sole afterwards to avoid stubbing issues. You should check with a clubmaker, but I believe it takes a lot of tape ounces to recover 30 points of swingweight.
I have had some experience with pouring material down inside the shaft for added weight. This not only adds swingweight, but it also changes shaft flex and vibrational qualities by stiuffening the shaft. Different materials have a different specific gravity and density, so the actual distribution of added mass inside the shaft will vary depending on what material you use -- sand, salt, some other mineral or powder. The denser material would pack more mass lower into the shaft, and this probably doesn't stiffen the total shaft as much (not sure). And some materials may corrode the shaft from the inside (e.g., salt) over ten or more years. The mass in the shaft makes the putter feel heavier overall, and I like this, since it helps pull your hands down into a relaxed position and makes the putter have greater stability from its greater inertial properties, and this keeps it on track more smoothly than a lighter putter overall.
The final point is about adding or subtracting weight to the handle, either by using a different grip or placing a counterweight in the top of the shaft. There is a company that makes counterweights to place in the top of the shaft. This certainly affects swingweight, but seemingly in the wrong direction. Swingweight is not the idea here. Instead, the weight affects the shaft's vibrations. Every putter shaft has a pattern of how the vibrations "stand" along the length of the shaft, and there is usually a "node" where the frequencies cancel out and there is no vibration. This node is a result of shaft design and swingweight, and is typically located low down the handle near the metal. You can see it by "striking" the sole of the putter straight down onto the ground in the manner of a tuning fork and running you fingers lightly up the shaft until you feel the no-vibe spot. You might actually be able to "see" the node, too, depending upon how much your putter shakes when "struck" this way. The idea of the counterweights is that the node is too low, and ought to be located inside the center of your hands for superior "feedback" feel (the after-the-fact sort). So the counterweight moves the node upward so youy can get your hands on it better. A perfectly customized counterweighting would start with your setup and then use just the right weight to move the node precisely afr enough to match your setup. But mass marketing being what it is, the scheme really just throws the node higher up the standard grips and leaves it to you to find it.
What I find is that using a 35" putter but gripping low down the handle gets me on the node anyway, without the necessity of counterweighting at the top of the shaft. And I don't lose swingweight from EITHER cutting the shaft or adding weight at the top of the shaft. What seems to be needed is a putter that is properly built to start with, in terms of length, lie, swingweight, shaft, and all -- OR a 35" putter with an extra low grip!
Geesh, I know this is way too long, but I hope it helps.
Cheers!
Geoff Mangum
The PuttingZone
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