Golf Physics - Why the DST Golf Training Aid Clubs Fail

[iacas]

http://www.dstgolf.com/optimise-golf-swing/how-dst-golf-clubs-work

Quote

How DST Golf Clubs Work

The Secret of Golf is to have a delayed strike or lag impact where your hands lead the club face through the ball. As a result the club face is under control until after the ball has been struck. Enabling you to consistently improve your ball strike and accuracy.

The DST clubs have been designed with a specific sole angle. The sole is also wide and flat so that the club orientates itself horizontally on the ground in the set up position with the shaft of the club leaning forwards, towards your lead shoulder (which is the center of the club head arc).

The DST clubs incorporate a Hand Position Alignment Marker (HPAM) which runs at an angle down the front of the hosel. When the HPAM is aligned with your eye line and the leading groove on the club face, you have located the most logical set up position and optimal impact position. All you have to do is complete your normal swing but return the club to the same position through impact  and you will have reached the Optimal Impact Position.

You'll notice that everything in that description talks about how the shaft appears, or how a line appears, so that you set up properly. In essence, everything - the shaft being bent, the wide sole with a specific bounce, and the line near the hosel - is geared toward one thing: to get the handle forward at setup.

As you can see, I've done that here in two swings:

So far so good, right? I added a white line so that you can see the curve in the shaft. I will tell you that it appears to be more severe at setup.

Unfortunately, the simple physics of swinging a golf club are that the heavy part - the mass at the end of the stick - wants to line up and form a straight line pointing at the center of the arc on which it's being swung. Consider tying a small weight to the end of a string. Swing it around: over your head, in front of you, beside you, on an angle… and you'll notice that the weight pulls the string tight. Simple physics.

So, whether you flip or not, the weight on the end of the string (the clubhead) pulls the string (the shaft) taut. On the left, my weight is moving back and I'm throwing or flipping the clubhead. On the left, a "good" swing.

This renders the DST a "visual" training aid only. It fails at doing much more than your clubs do already at letting you know whether you flipped at the ball or not.

Here are the videos:

[Mr. Desmond]

Thank you for saving me $$$

[SavvySwede]

I guess the guys at DST never watch golf on TV. All those slo-motion swings with the Swing Vision camera and they never noticed the shaft wasn't actually bent like that at impact?

[mvmac]

I think the visual aspect can be a useful educational tool, especially for beginners to illustrate roughly where you want to be at impact. There are also some golfers out there that still think impact and address are basically the same.

Thanks for posting @iacas. Another "miss" for impact training tools, just do the 2-Ball drill 

[collapse]

One thing we can be sure of ,the DST won't solve the golfers problems.It does say however what is needed,but we know that already.Feel ,the great foggy golf term, is what pros live by. It essentially is a golf life time of trial and error trying to gain control of the fingers and forearm muscles impact on holding and  swinging a golf club.Swinging a baseball bat doesn't present the same problems as swinging a golf club because only the wrist hinge is involved.But when bending ,as with a golf club,the added wrist cocking issue complicates what is an otherwise simple non- feel, merely power motion of the baseball swing. DST---Doesn't Solve Tension.

Edited November 24, 2015 by collapse

[RandallT]

I'm amazed the club actually straightens out like that. Great video.

[Gridiron]

Thanks for taking the time to post this in response to my post on another thread.  Appreciate it.

[Nosevi]

Was sent a link to this thread by another member. Was due to be leant a DST club tomorrow but don't think I'll bother. Thanks for the descriptions and vids, Erik.

[Phil McGleno]

Interesting-Do you think it works as a visual help at setup?

[iacas]

4 minutes ago, Phil McGleno said:

Interesting-Do you think it works as a visual help at setup?

Yes.

What value there is in that I'll leave to individuals, particularly since you don't play golf with it. You could, but what I'm saying is that when you go back to your regular "straight" clubs, the visual is lost. And all the visual does is put your hands forward at setup, which… you could do anyway.

 

[Divot Tool]

On 11/23/2015 at 7:27 PM, iacas said:

http://www.dstgolf.com/optimise-golf-swing/how-dst-golf-clubs-work

You'll notice that everything in that description talks about how the shaft appears, or how a line appears, so that you set up properly. In essence, everything - the shaft being bent, the wide sole with a specific bounce, and the line near the hosel - is geared toward one thing: to get the handle forward at setup.

As you can see, I've done that here in two swings:

So far so good, right? I added a white line so that you can see the curve in the shaft. I will tell you that it appears to be more severe at setup.

Unfortunately, the simple physics of swinging a golf club are that the heavy part - the mass at the end of the stick - wants to line up and form a straight line pointing at the center of the arc on which it's being swung. Consider tying a small weight to the end of a string. Swing it around: over your head, in front of you, beside you, on an angle… and you'll notice that the weight pulls the string tight. Simple physics.

So, whether you flip or not, the weight on the end of the string (the clubhead) pulls the string (the shaft) taut. On the left, my weight is moving back and I'm throwing or flipping the clubhead. On the left, a "good" swing.

This renders the DST a "visual" training aid only. It fails at doing much more than your clubs do already at letting you know whether you flipped at the ball or not.

Here are the videos:

Quote: “ Unfortunately, the simple physics of swinging a golf club are that the heavy part - the mass at the end of the stick - wants to line up and form a straight line pointing at the center of the arc on which it's being swung”

That happens because you’ve thrown away all the lag pressure.  The club is designed to strike the ball with the hands ahead as a result of lag tension.  Per your videos, at impact your hands indicate that you haven’t retained that pressure.

 

[Vinsk]

7 hours ago, Divot Tool said:

That happens because you’ve thrown away all the lag pressure.  The club is designed to strike the ball with the hands ahead as a result of lag tension.  Per your videos, at impact your hands indicate that you haven’t retained that pressure.

I think it’s just physics. Lag tension? 

[iacas]

7 hours ago, Divot Tool said:

Quote: “ Unfortunately, the simple physics of swinging a golf club are that the heavy part - the mass at the end of the stick - wants to line up and form a straight line pointing at the center of the arc on which it's being swung”

That happens because you’ve thrown away all the lag pressure.  The club is designed to strike the ball with the hands ahead as a result of lag tension.  Per your videos, at impact your hands indicate that you haven’t retained that pressure.

No.

[Divot Tool]

15 hours ago, iacas said:

No.

Care to elaborate?

 

I think Bertie Cordle would disagree with you.  @ 00:50 both swings clearly illustrate that you’ve lost all lag tension at impact . . .flip or no flip.  DST is designed to work with hands ahead of ball at impact via lag pressure . 

 

 

 

 

[Vinsk]

1 hour ago, Divot Tool said:

Care to elaborate?

 

I think Bertie Cordle would disagree with you.  @ 00:50 both swings clearly illustrate that you’ve lost all lag tension at impact . . .flip or no flip.  DST is designed to work with hands ahead of ball at impact via lag pressure . 

 

 

 

 

CONTROVERSY ABOUT LAG TENSION? - BE BETTER GOLF BLOG

---

Former tour pro and owner of training aid company DST Golf Bertie Cordle has made quite the splash on Be Better...

I'm out of my league in this stuff but I’m trying to understand this discussion. I watched an interview with Bertie and then read this article. 

This concept of ‘ lag tension’ is a bit perplexing to me. The article even shows a picture of an ‘anonymous pro’ with ‘zero lag tension.’ It then lists some high level pros and their ‘ lag tension’ amounts. So there are tour level pros with varying amounts of lag tension. So what? This device you stated is designed to work with golfers who create positive lag tension. But it appears to me if you already have positive lag tension then what good is this device?

The picture of the anonymous pro shows his hands are ahead of the ball but that the line from his lead elbow through his wrist and to the ground is even with ball thus zero lag tension. Again, so what? He’s delivering a downward blow and obviously a good ball striker as he’s on tour.

It states Koepka as having ‘ a ton of lag tension’ and JT as just having ‘a lot.’ Once again, so what? They’re both top level golfers who crush the ball. Can you please elaborate what this device is suppose to do to help amateurs achieve more ‘ lag tension’ and why is more better than just being on the positive end or zero. 

[iacas]

3 hours ago, Divot Tool said:

Care to elaborate?

Sure. After I mow the lawn.

But, the short version is… there's really no such thing as "lag tension," nor would I have any reason to want it at impact for a normal golf swing.

I'll merge the posts when I'm done.

---

Here goes… the simple version, because I could write a LOT about this. It's pretty simple physics, mixed with some basic biomechanics, and a little golf knowledge.

I'll make two basic points:

First, the DST club would have to be incredibly stiff to resist straightening out. The CG of the club, near the clubhead, wants to line up, the same way a rock tied to a string when swung around in a circle (on any angle) pulls the string tight. The weight of the clubhead, thus, pulls the shaft in the DST straight - whether I flip or hit a solid shot that lines up with the lead shoulder.

On 11/23/2015 at 7:27 PM, iacas said:

This renders the DST a "visual" training aid only. It fails at doing much more than your clubs do already at letting you know whether you flipped at the ball or not.

BTW, I just noticed that when I went back up to get that quote, I made the same rock-on-a-string analogy up there. Why? Because it's true. Heck, if I want to be picky about it, most shafts are actually in slight forward deflection at impact.

Second, the idea of lag pressure or "lag tension" is bull. I could give a TON of data, physics, blah blah blah on this, but I'll try to make a few quick bullet points:

• I can generate a ton of "lag tension" (as he measures it, with a line from the lead elbow to the wrist) with just my lead hand on the grip… or negative "lag tension."
• If you actually push with the bottom hand in a grip, you'll throw away the lag faster than anything.
• Too much lag pressure is a bad thing, too: the best players tend to have a shaft pointing near the lead shoulder at impact, not several inches in front of it.
• Lag pressure is a reaction.
• Phil Mickelson, Vijay Singh, Fred Couples… you can find photos of each of them where their trail hand is almost coming off the club around impact.

Now, you'd originally said this:

On 9/4/2019 at 12:39 PM, Divot Tool said:

That happens because you’ve thrown away all the lag pressure.  The club is designed to strike the ball with the hands ahead as a result of lag tension.  Per your videos, at impact your hands indicate that you haven’t retained that pressure.

The impact on the right - the one where I'm making a good swing and not throwing the clubhead at the ball like amateurs who flip - is plenty good. The shaft points pretty much straight up toward my lead shoulder with about 7° forward shaft lean.

I want you to think about where you think this "pressure" should be, and ask yourself how you'd get pressure to be higher or lower in that place, and consider what the hands are doing around impact (decelerating), what the shaft is doing relative to the lead arm at impact (rotating faster or passing the lead arm), and where what's commonly called the "coupling point" exists (between the hands - the bottom hand is below the coupling point).

[Divot Tool]

2 hours ago, Vinsk said:

CONTROVERSY ABOUT LAG TENSION? - BE BETTER GOLF BLOG

---

Former tour pro and owner of training aid company DST Golf Bertie Cordle has made quite the splash on Be Better...

I'm out of my league in this stuff but I’m trying to understand this discussion. I watched an interview with Bertie and then read this article. 

This concept of ‘ lag tension’ is a bit perplexing to me. The article even shows a picture of an ‘anonymous pro’ with ‘zero lag tension.’ It then lists some high level pros and their ‘ lag tension’ amounts. So there are tour level pros with varying amounts of lag tension. So what? This device you stated is designed to work with golfers who create positive lag tension. But it appears to me if you already have positive lag tension then what good is this device?

The picture of the anonymous pro shows his hands are ahead of the ball but that the line from his lead elbow through his wrist and to the ground is even with ball thus zero lag tension. Again, so what? He’s delivering a downward blow and obviously a good ball striker as he’s on tour.

It states Koepka as having ‘ a ton of lag tension’ and JT as just having ‘a lot.’ Once again, so what? They’re both top level golfers who crush the ball. Can you please elaborate what this device is suppose to do to help amateurs achieve more ‘ lag tension’ and why is more better than just being on the positive end or zero. 

The best ball strikers who ever lived utilized lag pressure and knew when to release it.  They understood that impact required a flat left wrist.  Impact is still the moment of truth. 

Trevino, Hogan, Knudson, Norman, Nicklaus, Player, Woods, Mickelson, Rahm, DJ, Rory, Day, Speith, JT, Brooks, Stenson et al . . . they all did it/do it.  

OP rendered the DST compressor as a 'visual training aid only.'  I disagree as the club is designed to visually mimic impact from the perspective of the golfer.  Compare 99% of amateur golfers at impact to those mentioned above and you'll see why Bertie makes his case.  

 

 

 

[iacas]

1 hour ago, Divot Tool said:

The best ball strikers who ever lived utilized lag pressure and knew when to release it.

No.

1 hour ago, Divot Tool said:

They understood that impact required a flat left wrist.  Impact is still the moment of truth.

Fred Couples had a cupped lead wrist at impact (still does). Jordan Spieth and Lee Westwood do/did too. Plenty of great ball strikers have had arched left wrists, too.

You're buying into some old ways of thinking that have been disproven as accurate. We know quite a bit about the actual forces that exist in the golf swing, when and where they're in play, etc.

And again, Vijay, Freddie, Phil, and many, many other PGA Tour players actually have the trail hand almost completely off the club at impact. I can make a swing with a ton of lag without the trail hand being on the club at all.

1 hour ago, Divot Tool said:

Trevino, Hogan, Knudson, Norman, Nicklaus, Player, Woods, Mickelson, Rahm, DJ, Rory, Day, Speith, JT, Brooks, Stenson et al . . . they all did it/do it.

They all did/do what? You've not actually said anything.

1 hour ago, Divot Tool said:

OP rendered the DST compressor as a 'visual training aid only.'

It is. The club shaft straightens out when you swing it at a certain speed.

I have video of Justin Rose swinging one on the range at the Memorial in Ohio. Guess what? The club shaft is straight at impact. Simple physics.

1 hour ago, Divot Tool said:

I disagree as the club is designed to visually mimic impact from the perspective of the golfer.

VISUALLY.

It doesn't actually, nor could you actually see the shaft at impact when you're swinging it.

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On 11/23/2015 at 7:27 PM, iacas said:

Good swing on the right, bad one on the left. The shaft is straight for both.

The DST is a visual-only training aid. It gives you the idea of what and where your hands should be at impact, but… that's of limited use in my experience, because nobody can actually see/feel exactly where their hands are at impact on a shot.