Offset Irons: Conventional Wisdom vs Reality

[Tee2Trees 8]

The Ping golf company was said to revolutionize golf with their introduction of the Eye2 irons.  These irons featured perimeter weighting and healthy offset.  These were almost universally regarded as the easiest irons to hit for many years to come.  It the decades since, the perimeter weighting feature has been widely adopted while the healthy offset feature has been less so.  What are the benefits or disadvantages associated with offset?

"Offset helps close the face quicker and can lead to hooks."  FICTION.

If this is ever true it is due to psychology at setup.  If one properly sets up with the clubface behind the ball and facing the target the face will close in the same amount of time, i.e. at the same point in the swing, regardless of offset.  It's not like an iron byron machine will start hooking the ball if one attaches an offset club.

"Offset irons get the ball up quicker."  FICTION

The offset puts the hands (further) ahead of the ball at impact.  This will help someone with an early release reduce flipping and keep the launch down in addition to producing cleaner strikes.  If anything, the offset feature counters the effect of high launch produced by the wide, heavy sole normally seen in the same category of irons.

"Offset irons have a higher moment of inertia."  FACT

Simply put, the center of mass is further away from the axis of rotation (the shaft).  This is the same reason driver heads have gotten so large from front to back.  The offset irons have a greater resistance to twisting on off-center strikes.

"It is harder to work the ball with offset irons."  NOT FACT

This all depends on what you mean by "work the ball".   A golfer who is well-practiced with their clubs can produce a slice or hook with pretty much anything out of any clean lie.  Flighting the ball in terms of high-low trajectory is another story and can be compromised with game-improvement clubs.  I will get into the reasons for this probably in another thread.

Maybe you have dismissed offset irons for fear of the hooks or a high ball flight.  I believe this is simply a prejudice caused by myth.  If your ballstriking could stand improvement in general, I would recommend giving a heavily offset mid-iron a try-out on the driving range.  Start with the ball teed up to remove ground interation from the equation and see if it helps you strike the ball cleaner or flight it better.

[iacas 3,568]

I've said for awhile now: offset simply makes people set up with the clubface pointed more in the "closed" direction (to the left for a righty). That's all.

[Lihu 511]

I've been training with blades, Cleveland cg tour and mizuno mp32, so there's very little offset. When I switch to my play clubs, any of the following sets the burner 1.0, callaway x20, ping i10 or i20, there doesn't appear to be much of a difference. Just that toe shots don't hurt, and they go higher and further. Btw, I have way too many clubs to choose from. Lefties have to hoard. :-P

[saevel25 930]

Originally Posted by iacas

I've said for awhile now: offset simply makes people set up with the clubface pointed more in the "closed" direction (to the left for a righty). That's all.

That's interesting. When at the golf outing last month, i was demoing that swing path board. I wasn't hitting the little plastic arm, telling me the path was ok, but the ball was starting left and drawing left. So, big time emphasis on were my clubface is pointing. I know Taylormade has some serious offset for their game improvement irons.

[Lihu 511]

Taylormade has some serious offset for their game improvement irons.

I tried out the Rocketbladz (non-tour) and the offset is not that big. I did not have a chance to see their other sgi offerings, those were double the price anyway.

[mvmac 1,631]

Originally Posted by Tee2Trees

"Offset irons have a higher moment of inertia."  FACT

Simply put, the center of mass is further away from the axis of rotation (the shaft).  This is the same reason driver heads have gotten so large from front to back.  The offset irons have a greater resistance to twisting on off-center strikes.

This might have to do with more of the design of most irons that have a good amount of offset.  Wide soles, perimeter weighting etc.  If you took a set of musclebacks and had them made with PING G25 offset, would the change of MOI be that significant?

[Lihu 511]

I should bring all my clubs to the range sometime, and compare them side by side.

[WUTiger 370]

Originally Posted by Tee2Trees

... "It is harder to work the ball with offset irons."  NOT FACT

This all depends on what you mean by "work the ball".   A golfer who is well-practiced with their clubs can produce a slice or hook with pretty much anything out of any clean lie.  Flighting the ball in terms of high-low trajectory is another story and can be compromised with game-improvement clubs.  I will get into the reasons for this probably in another thread. ...

There's more involved here than clubhead design. Don't forget about the shaft (that tube that run between your Golf Pride grip and the clubhead).

Flighting varies even among SGI clubs, according partly to shaft. Both the Big Bertha and the G10 irons, with stock high-launch shafts, would really hand the ball up in the air. The stock Callaway X20s, however, came with a Uniflex mid-launch shaft. I didn't have trouble with "too much lift' on windy days.

And, make sure you distinguish between SGI and GI clubs. I play X20 Tours. These GI irons, along with the Cleveland CG16 Tours, had some offset, but much less than the SGI irons. These irons have noticeable cavity features, but less offset than the SGI.

Then, there's the problem with the Golf Digest Hot List club classifications. Whereas Hot list considered the X20 irons as SGI, the newer,  comparable X.Hot irons are considered GI. Although the two models have similar offset, the X.Hot lofts are stronger. Hot List classifications result from perceived market niche, not any scientific formula.

[Lihu 511]

My son has recently started using my old burners with good success. He can get that low penetrating flight with them, while I never have. These clubs have lots of offset. He also can't hit my newly acquired mp32 with KBS tour shafts in them. I hit them with a high 30 yard parabolic flight. Still not quite hitting the sweet spot, and not getting enough lag, maybe? In any case, they go far enough for my game, and have almost no offset. The more clubs I have, the more I feel that the person and the club need to be matched for optimim performance. Hence, fitted well. I think there are this many designs because there are so many different types of golfers.

[saevel25 930]

Just for the sake of proving offset is just a visual thing,

Taylormade Max irons have a pretty big offset, 0.240" for their 3 iron, down to 0.122 for their pitching wedge.

Comparing that to a Taylormade RocketBladez Tour, which has 0.138 for the 3 iron, and 0.075 for the pitching wedge.

I was curious to see how much time offset gives the club to close more.

Lets just assume that a person hits their 3 iron with a 88 mph club head speed. That's about 10 mph less than an average pro. Just to give some leeway.

So basically the offset difference is only giving you 66 milliseconds of extra time to close the clubface down.  Honestly that is a crazy short amount of time, the clubface isn't going to close down any significant amount.

I believe what Erik has mentioned, that the clubface will be aimed more left rather than the actually physics is causing the ball to go left with any significance.

[iacas 3,568]

Just for the sake of proving offset is just a visual thing,

Taylormade Max irons have a pretty big offset, 0.240" for their 3 iron, down to 0.122 for their pitching wedge.

Comparing that to a Taylormade RocketBladez Tour, which has 0.138 for the 3 iron, and 0.075 for the pitching wedge.

I was curious to see how much time offset gives the club to close more.

Lets just assume that a person hits their 3 iron with a 88 mph club head speed. That's about 10 mph less than an average pro. Just to give some leeway.

So basically the offset difference is only giving you 66 milliseconds of extra time to close the clubface down.  Honestly that is a crazy short amount of time, the clubface isn't going to close down any significant amount.

I believe what Erik has mentioned, that the clubface will be aimed more left rather than the actually physics is causing the ball to go left with any significance.

That's funny; I did that same math somewhere on the site a few years ago, but then related it to a rate of closure to see how much more a face could close during whatever time period I came up with (using whatever offset and swing speed I used).

[saevel25 930]

That's funny; I did that same math somewhere on the site a few years ago, but then related it to a rate of closure to see how much more a face could close during whatever time period I came up with (using whatever offset and swing speed I used).

I was going to post the numbers for that, but I wasn't sure if I was stretching the logic to far. but for my example I assumes 90 degree closure in 0.33 seconds, and came up with something like 0.014 degrees more closed if I remember right.

[birlyshirly 4]

"Offset irons have a higher moment of inertia."  FACT

Simply put, the center of mass is further away from the axis of rotation (the shaft).  This is the same reason driver heads have gotten so large from front to back.  The offset irons have a greater resistance to twisting on off-center strikes.

Strictly speaking, the MOI that you're concerned about in providing forgiveness for off-centre strikes is the MOI around the clubhead's CoG, not the shaft.

 

Quote

 

Originally Posted by mvmac

This might have to do with more of the design of most irons that have a good amount of offset.  Wide soles, perimeter weighting etc.  If you took a set of musclebacks and had them made with PING G25 offset, would the change of MOI be that significant?

 

Not very significant - would be my guess. Because you're really talking about redistributing the mass of the hosel further in front of the clubhead CoG - rather than the main mass of the clubhead being further from the axis of rotation of the shaft.

Quote

Originally Posted by saevel25

Just for the sake of proving offset is just a visual thing,

Taylormade Max irons have a pretty big offset, 0.240" for their 3 iron, down to 0.122 for their pitching wedge.

Comparing that to a Taylormade RocketBladez Tour, which has 0.138 for the 3 iron, and 0.075 for the pitching wedge.

I was curious to see how much time offset gives the club to close more.

Lets just assume that a person hits their 3 iron with a 88 mph club head speed. That's about 10 mph less than an average pro. Just to give some leeway.

So basically the offset difference is only giving you 66 milliseconds of extra time to close the clubface down.  Honestly that is a crazy short amount of time, the clubface isn't going to close down any significant amount.

I believe what Erik has mentioned, that the clubface will be aimed more left rather than the actually physics is causing the ball to go left with any significance.

 

 

 

Quote

Originally Posted by iacas

That's funny; I did that same math somewhere on the site a few years ago, but then related it to a rate of closure to see how much more a face could close during whatever time period I came up with (using whatever offset and swing speed I used).

 

 

I don't doubt the maths - but I think that moving the CoG of the clubhead rearward of the shaft will, in some though perhaps not all cases, impact on how the shaft behaves in the impact area, with consequential effects on both clubface alignment and dynamic loft.

Quote

Originally Posted by Tee2Trees 

Maybe you have dismissed offset irons for fear of the hooks or a high ball flight.  I believe this is simply a prejudice caused by myth.  If your ballstriking could stand improvement in general, I would recommend giving a heavily offset mid-iron a try-out on the driving range.  Start with the ball teed up to remove ground interation from the equation and see if it helps you strike the ball cleaner or flight it better.

 

 

After all this, I'm not actually sure what the proposed advantages of offset are. I don't think the MOI effect is substantial. I think a higher, or lower (however you think offset actually works) flight would be easier achieved by bending the neck to adjust loft. I think the draw bias from offset is probably minor - less substantial I think than from bending the lie of your irons.

I think offset is largely an eye-appeal thing. Some players hate it - perhaps because they've heard the marketing BS and BELIEVE that it introduces a draw bias. Other players maybe like it because, for the same reason, the believe that it's providing them a margin of forgiveness that isn't really there. Certainly, if you spend years playing either low-offset players blades, or high offset SGI clubs - you'll probably get comfortable with what you're used to looking at.

[saevel25 930]

I don't doubt the maths - but I'm not sure that this is the wholly correct way to model the effect of offset. I think that moving the CoG of the clubhead rearward of the shaft will, in some though perhaps not all cases, impact on how the shaft behaves in the impact area, with consequential effects on both clubface alignment and dynamic loft.

After all this, I'm not actually sure what the proposed advantages of offset are. I don't think the MOI effect is substantial. I think a higher, or lower (however you think offset actually works) flight would be easier achieved by bending the neck to adjust loft. I think the draw bias from offset is probably minor - less substantial I think than from bending the lie of your irons.

I think offset is largely an eye-appeal thing. Some players hate it - perhaps because they've heard the marketing BS and BELIEVE that it introduces a draw bias. Other players maybe like it because, for the same reason, the believe that it's providing them a margin of forgiveness that isn't really there. Certainly, if you spend years playing either low-offset players blades, or high offset SGI clubs - you'll probably get comfortable with what you're used to looking at.

Here's the thing your not hitting the club with the shaft, your hitting it with the Club head. So the MOI overall for the club head due to weighting is much more significant than any MOI that is due to moving with off set.

Also, Offset is what, 0.10-0.15" between player and GI irons. So, lets say 0.13".

So this means that the GI club head is set back 0.13" (away from the target). If you swing the same, then your ball position must be back 0.13" or your going to end up a few grooves fat on the club face (higher on the club face) than you normally would. So what happens, your hands react to the club. You start to flip at the ball slightly. Even then, lets say for a 37.25" 6 iron, your only talking about 0.19 degrees of flip.

Once again, there is no significant benefit to offset other than how it looks at set up.

[Mike Boatright 22]

Off set and low cg means high and left just about every time unless you open the face and play the ball back in your stance. The only thing that makes these kinda irons good is their luanchability and forgiveness.

[billchao 358]

Off set and low cg means high and left just about every time unless you open the face and play the ball back in your stance. The only thing that makes these kinda irons good is their luanchability and forgiveness.

I agree that low CG will result in high launch, but disagree about the offset. I play clubs with a good amount of offset and can/have hit them both left and right. You can't really make a blanket statement about something that's personal, like preferences for offset, grip size, or shaft flex because it doesn't affect people the same way.

[Tee2Trees 8]

Off set and low cg means high and left just about every time unless you open the face and play the ball back in your stance. The only thing that makes these kinda irons good is their luanchability and forgiveness.

It's because they play a trick on your mind and make you rotate your wrists faster and flip through the release.

[SavvySwede 352]

I would rather have an iron with more perimeter weighting and less offset. The confidence of a good looking club you know you can align properly is a lot more beneficial than the forgiveness the offset provides.