Other Heft Issues
"Backweighting" is the practice of putting weight in
butt of the club. The weight is usually not more than 30 grams for
full-swing clubs. (Let's leave putters out of the discussion for now.)
does help some golfers, and does nothing for others. In fact,
experimenters who have tried it with careful testing, find that it may
help for some clubs and hurt for others.
This is a very curious phenomenon that just about begs for explanation.
So here goes...
- One of the better tests of backweighting that I have seen
was done by Jeff Summitt, Technical Director of Hireko Golf, in the summer of 2009. It used to
be available on their blog
site; a copy can now be found here.
The point of the test
was "to see what happens to ball speed when length and swingweight
changes." Summitt found that, even for the same golfer, a
27g backweight could add
7mph of ball speed or subtract 4mph of ball speed, depending on the
club. He saw nothing in his sixteen-driver one-golfer data to hint
at whether backweighting would help or hurt for any particular driver.
Here is a table of the two drivers he tested with and without
counterweight is shaded in blue. If you understand the
tutorial so far, you should have figured that out from the higher total
weight but lower swingweight.)
||Longest of CT-58,
straightest by far
with the counterbalance
- Tim Hewitt of MyOstrich Golf, one of the more experienced
people at fitting for backweight, has posted to SpineTalkers his
experiences and methods. His conclusion: "I don't know
of ANY science that has been able to predict which clubs will
benefit which player, or been able to find the commonality in finished
clubs that can predict the combination for the next club. I
even had single length iron customers benefit in odd clubs throughout a
set - with clubs that were virtually IDENTICAL club to club."
- Doesn't affect MOI -- We know that
weight at the butt of the club is not going to affect the moment of
inertia. So that isn't what is going on.
- Computer simulations -- I investigated
the effect of backweight, using Max Dupilka's "SwingPerfect"
program. It showed only a tiny effect from backweighting -- even with
backweights as high as 100
grams -- and less than a 0.1% effect from the sort of backweights that
are normally used. So there is nothing in the physics to support
backweighting a club.
- Wristwatch analogy -- If there were any
validity to backweighting, then a wristwatch or weighted bracelet
should have the same effect. A metal men's wristwatch weighs between 50
and 80 grams, quite a bit more than most backweights. And a wristwatch
just about the same effect on the equations of motion that a butt
weight would. Both would show up as extra mass very close to the hinge;
which side of the hinge it was on would make almost no difference in
the equations of motion that govern the swing. (That's true for any
physical model of the swing, not just Jorgensen's model.)
But, in fact, informal experiments have shown no effect due to
weight of a wristwatch on the wrist.
- More wisdom from Jeff Summitt -- In an
email discussion with
Jeff, I mentioned that robot testing does not show any effect from
backweighting. He responded, "You
are right, a robot will not tell any difference in counterbalancing,
but a human can (well at least some will). While at
had a very special test club that was counterbalanced by 30g (±2g),
can't remember exactly since it was so long ago. It was a
club, but not when you picked it up and tried to waggle it.
was an identical club sans counterbalance as a control.
Inevitably the students would swing the counterbalanced club faster and
change their swing from outside-in to inside-out. It was
amazing how it would work on some people but not all. "
My conclusion from all this is that backweighting is completely
subjective. It is a feel
issue, with no basis in the actual mechanics of the swing. The feel
must occur through the hands' grip on the club, not the arms nor
shoulders. (If it were arms or shoulders, then a wristwatch would have
the same effect as a backweight.) The golfer who responds to the feel
of a backweight does so by making a different swing
-- that is, apply more or less
force, perhaps at different times or in a different direction. This,
and not any physics phenomena,
is responsible for the effectiveness of backweight for some golfers.
This is the only explanation I can come up with that is consistent with
it is some kind of internal human feedback mechanism. It differs from
person to person and, within a single person, from club to club. So
far, we have not discovered any correlation that allows us to do much
better than trial and error in fitting a golfer for backweight. And any
science that can help the situation will not
physics (a better model of the swing) or technology (a better
backweight system). It will be number-crunching or eyeballing a lot of
human test data ( probably like Jeff Summit's), looking for
correlations. So far, nobody has tried that with any
Perhaps some day a graduate student doing a thesis project will attack
the problem. I don't see any other party with both the resources and
the motivation to do it.
None of this denies the effectiveness of
backweighting for some
golfers for some clubs. It just precludes any way to fit a golfer for
except old-fashioned trial and error. Maybe some day we will know
enough to do better.
Here are a few more
relevant points, added March 17, 2011:
- Wisdom from
Anderson probably has more experience fitting backweights
anybody. He says that they are almost universally helpful, but at
different weights for different golfers. Also, bear in mind that he
focuses just about exclusively on good golfers who are willing to work
and practice to get better. That puts his clientele in a small minority
to begin with. Anyway, Leith told me, "I
have done that hundreds of times. I use the
Achiever. I set the
benchmark with no weight. Then, I swap 5g, 10g, 15g, and 20g
and look for improved patterns in swing path, face angle at contact and
launch angle. The Achiever has one terrific report that shows
on one page with the average deviation numbers. I have
hundreds of customers counterweights. They stay
installed. I have
taken out two or three sets of counterweights and an occasional one
with a driver. I'm not saying it's 'pure science' because I
slip in a
little swing advice - most players don't know what they ought to be
trying to do." So Leith's approach is organized trial and
error, augmented by a lesson while he fits.
- How about
Since the helpfulness of backweight varies from golfer to golfer, it is
reasonable to ask if some golfers need negative backweight -- that is,
less weight in the butt of the club. It would be a huge coincidence if
only positive backweights help, given that the best weight varies
markedly, and many golfers are not helped at all (at least if we
believe Jeff Summitt's testing). And apparently there are a lot
of golfers who prefer a negative backweight. How do we know? Winn grips
makes a lot of money selling lightweight grips, maybe 10-25 grams
lighter than normal. But that is exactly the opposite of adding 10-25
grams of backweighting.
-- In fact, negative backweighting predates the popularity of
backweighting by several years. When TaylorMade came out with their
Bubble shaft in the mid-1990s, there was a lot of mystery and "magic"
about what it did. Those clubfitters who did their homework figured it
out fairly quickly, and it was both simple and surprising. By far the
biggest difference the Bubble shaft introduced was the ability to add a
very light grip. Very
light! In fact, it was 30-35 grams lighter than a standard grip. This
suited a large number of golfers, and the clubs were popular for years.
And their unique feature is a negative backweight of 30-35 grams. (Note
that a positive 30-35 grams is the very high end of
- The Heavy Club
-- Steve Boccieri of Boccieri Golf
pioneered a club named the Heavy Putter in 2004. He came up with a
putter head that was by far the heaviest on the market, then countered
the extremely head-heavy feel with a huge backweight (over 200 grams).
Since then, he has concluded that the same approach (albeit less
extreme) works for full-swing clubs, too. His company now makes the
Heavy Driver, Heavy Wedges, Heavy Irons, etc. He goes with a heavier
head (to make the golfer hit with the body rather than the hands) and a
slightly shorter overall length of club, then counters the extremely
head-heavy feel with a much bigger backweight than you would expect
from a typical Balance Certified fitting. For instance, the Heavy
Driver has a standard backweight of 50 grams. The trick in all the
Boccieri clubs is to add enough backweight so the balance point of the
club is actually significantly higher than the balance point of a
"normal" club of the same designation. For instance, the modern driver
has a balance point of about 12", while the Heavy Driver's balance
point is closer to 15".
Total weight is yet another measure of heft. That it can make a
difference is undeniable. In fact, Tom Wishon has said in many places
over the years
that total weight has a substantial effect on distance. In particular,
weight increases distance. I have been a skeptic for a long time.
This suggests that it matters how and where
you reduce the total weight of the club. For instance, you can make
major changes in the total weight of the club by backweighting, with no
predictable change in distance. In Tom's classic book on
he makes it clear that he is talking about total weight based on the
shaft material. Since he also believes in MOI as an important factor, I
would have thought he might agree that the MOI reduction may
indeed be as important as the total weight reduction. But no; he
maintains that total weight can increase distance even at the same MOI.
- Tom is completely committed to the importance of MOI as
to swingweight. I also believe that MOI is fundamental, and swingweight
is not -- and I went to some pains to make the case for that belief
earlier in this chapter. So let's just assume for this argument that
MOI matters and swingweight does not.
- The only ways to make a large difference in overall weight
the shaft weight (e.g.- ultralight graphite to standard-weight steel),
or backweighting (see above).
the shaft weight also affects the MOI of the club, so it has
other effects besides just changing the total weight.
- Changing the grip weight or adding butt weight does not
affect the MOI, so only the total weight
is affected. But, as we saw above, butt weight has no effect on
clubhead speed by itself. It may have an effect for some golfers, but
that is a feel issue that causes the golfer to change his swing.
To try to make some quantitative sense of this, I turned once again to
our "virtual robot", Max Dupilka's SwingPerfect
As usual for studies of this type, I tried a bunch of things before I
found a way to look at the data so it told me something interesting.
Here's that look:
about this club?
|Change total weight
using head weight alone
|Change total weight
using shaft weight alone
|Change both head and
shaft weight, to keep the
- All clubs were 45" drivers, with 52g
grips, 0.83 COR, and all other parameters the defaults of the program.
- The time interval used by the program
was reduced from
the usual 5 milliseconds to a half a millisecond, the minimum the
program supports. This gave much more consistent results, given the
small differences in clubhead speed we're looking at.
This data is not very conclusive. Yes, the ±30g clubs (shaft
weight) had the biggest clubhead speed changes. But the ±10g
clubs (head weight) had changes almost as large, and both were
substantially bigger changes than the ±20g clubs (constant MOI).
What's really happening here?
One thing we ignored in these runs is the fact that distance is a
function of ball speed, not clubhead speed. Yes, clubhead speed is a
major factor of ball speed, but it's not the only factor. Clubhead
also matters; a heavier head will provide a little more ball
Since we are looking at small changes in ball speed for not-so-small
changes in clubhead weight, we ought to factor this in.
Let's take another look at the data, with a couple of changes:
- We'll include ball speed.
- We'll sort the rows in order of total weight.
about this club?
|Head weight alone
|Shaft weight alone
|And here it is plotted as a graph.
This shows very clearly that Wishon is right. While
clubhead speed jumps around as we vary total weight, the ball speed
progresses smoothly, almost proportionally. In fact, it is nearly a
straight line, with a slope of 1mph of ball speed for every 10 grams of
As an example of what is possible, look at the two yellow rows of the
chart. Each has the same MOI (the same basic heft feel) as the base
club. But one is 40g lighter than the other, and gives 4mph more ball
speed. That translates into six to ten extra yards of distance. No,
it's not going to turn you into a "big hitter".
But it's a pretty sizeable increase, among those things that just club
design can do.
Of course, there are practical limits to how much you can do by
reducing total weight. Here are some of the more important
|Most of this section has been
devoted to the
importance of MOI as the fundamental
clubfitting measure of heft. So we mustn't change the MOI away from a
proper fit, while we're trying to get the club lighter.
The basic equation
shows how to manage this. Each gram of change in head weight is worth
three grams of change in shaft weight. So, if we go to a shaft that is
30 grams lighter, we need to add 10 grams to the head to preserve the
same MOI. (That explains the numbers in the yellow rows of the chart.)
So we can't put the full impact of a lighter shaft into total weight;
have to be satisfied with 2/3 of it.
|John Ford, president of The Golf
Naples, FL, has probably built clubs for more golfers than any
clubmaker I know, from PGA Tour pros to senior beginners. His take on
total weight is that many golfers need a lighter weight just to deal
with lower strength or fatigue. Golfers with low fitness, especially
themselves "swinging tired" toward the end of a round. John feels that
graphite shafts -- in other words, lower total weight -- may stave off
this fatigue and allow the golfer to finish the round reasonably fresh.
|On the other side of the coin, the
golfer may require a heavier overall club -- not just a higher MOI
or swingweight -- to regulate his swing. I don't know how usual this
is, but I am certainly one of those golfers. Up until very recently, I
used irons with steel
shafts. Every year or so, I built an experimental graphite-shafted iron
to see if I'm old enough to need the lighter weight. Every time I did,
I found that my irons are not as reliable; the good hits flew longer
higher with graphite, but I had too many "yips" where I released the
club too early and got a big pull. Since irons are about dependable
distance, not maximum distance, this is unacceptable.
The last time I did this (in 2009 at age 68), I kept adding weight to
the clubhead and
trying again, until the MOI was considerably more than that of my
steel-shafted irons. At that point, I was getting pretty reliable
impact and a bit more distance than my steel shafted irons. So I have
finally made the transition to graphite. But it took a long time, and
it still is not for everybody. Younger, stronger players are probably
better off using the extra weight of steel to regulate their irons.
Last modified -- Jan