Draw/Fade on command - Cavity Backs vs Blades

[Johnny1putt]

OK, so the "old school' thought is that blades make it easier to work the ball.  Nothing new there.  Here's my question/thoughts.   If we now know (via Trackman) that the difference between the path of the clubhead and the angle of the face is what creates the ballflight.... is it logical to say that the "old school" thought is untrue?

In other words.... if I have for example.. a Mizuno MP33 7 iron in my hands...and my path is coming from 3 degrees inside the target line (or 3 degrees right of target) and the face angle is 2 degrees out... that should create a slight draw.  Correct?

Same path, face angle, etc... but a Mizuno game improvement iron this time (JPX 800) which is supposedly harder to "work"... does this produce the same draw?

I guess the bottom line is I really want to know am I hampering my ability to draw/fade on command with a GI iron?  Or is that hogwash?  I know it's a little harder to flight the ball down due to the CG being lower... but I am referring to left/right movement.

Hope this makes sense & I explained it correctly

[Golfingdad]

Originally Posted by Johnny1putt

OK, so the "old school' thought is that blades make it easier to work the ball.  Nothing new there.  Here's my question/thoughts.   If we now know (via Trackman) that the difference between the path of the clubhead and the angle of the face is what creates the ballflight.... is it logical to say that the "old school" thought is untrue?

In other words.... if I have for example.. a Mizuno MP33 7 iron in my hands...and my path is coming from 3 degrees inside the target line (or 3 degrees right of target) and the face angle is 2 degrees out... that should create a slight draw.  Correct?

Same path, face angle, etc... but a Mizuno game improvement iron this time (JPX 800) which is supposedly harder to "work"... does this produce the same draw?

I guess the bottom line is I really want to know am I hampering my ability to draw/fade on command with a GI iron?  Or is that hogwash?  I know it's a little harder to flight the ball down due to the CG being lower... but I am referring to left/right movement.

Hope this makes sense & I explained it correctly

I think you explained it perfectly and I agree with all of your hypotheses.

[GaijinGolfer]

Blade or cavity back only matters when you miss the center of the clubface.  Either way, you are hitting a round object with a flat object draw/fade is determined by path, so how the mass is positioned on the back of the clubhead really makes no difference.

[rehmwa]

fades and draws (workability) are different than controlling the take off angle (controllability)

cavity backs are supposed to make the club less sensitive to the inputs to controlla bility.  It pushes the center of mass of the club head down closer to the sole to let it hit below the center of mass of the ball better.  i.e., it helps get the ball up easier.....

blades, the center of masses are closer aligned in the vertical direction - so closer to the tipping point, so more sensitive to the manner in the which the Pro (or beginner) chooses (or accidentally) hits the ball.

[mvmac]

Originally Posted by Johnny1putt

In other words.... if I have for example.. a Mizuno MP33 7 iron in my hands...and my path is coming from 3 degrees inside the target line (or 3 degrees right of target) and the face angle is 2 degrees out... that should create a slight draw.  Correct?

Same path, face angle, etc... but a Mizuno game improvement iron this time (JPX 800) which is supposedly harder to "work"... does this produce the same draw?

On a center hit, yes, should produce about the same shot.  The GI will launch higher.  GI irons will tend to fly straighter and possibly farther on off-center hits.

Posted this earlier to day:

Blade irons , or GI irons , it's still works the same..... strike the ball with the center of the face, and the ball will start in the direction the face is pointing, and will curve relative to the face angle/path.  The GI iron can have a different CoG location, generally lower and further away from the face but that difference will have a small impact on the work-ability of an iron . It's more to do with the trajectory (height) of a shot, though, and even then it can be subtle.  Blade irons have a CoG that is higher and closer to the face which will produce a lower trajectory.  A CoG low and rearward in the head will produce a higher trajectory.

[iacas]

Changes to the spin loft can subtly change the amount the spin axis will tilt with a GI over a non-GI iron. It's subtle, but it's there - the GI's lower CG helps effectively raise the "delivered loft" thus widening the spin loft and reducing tilt.

Also, non-GI irons (blades) are easier to hit lower.

[saevel25]

I have to agree, try to hit a hybrid low versus a long iron low, but yes if you lower the center of gravity and increase MOI, your going to have less control over the ball, and how much it curves.

[M2R]

Originally Posted by mvmac

On a center hit, yes, should produce about the same shot.  The GI will launch higher.  GI irons will tend to fly straighter and possibly farther on off-center hits.

Originally Posted by iacas

Changes to the spin loft can subtly change the amount the spin axis will tilt with a GI over a non-GI iron. It's subtle, but it's there - the GI's lower CG helps effectively raise the "delivered loft" thus widening the spin loft and reducing tilt.

Also, non-GI irons (blades) are easier to hit lower.

Originally Posted by saevel25

I have to agree, try to hit a hybrid low versus a long iron low, but yes if you lower the center of gravity and increase MOI, your going to have less control over the ball, and how much it curves.

I thought I was on board with this until saevel posted "have less control over ... how much it curves". Up to that point I was interpreting "about" and "subtly" to mean in theory yes there is a difference but in practice for 98% of golfers (or all?) no meaningful differences. The vertical component I'm totally on board with, it is the horizontal aspect that I'm questioning.

Or for a practical example a JPX 825 Pro PW compared to a MP-14 PW, which has more control over shaping a shot? The JPX PW is 45º and the MP-14 is 50º, if the effective increase in "delivered loft" on the JPX is less than 5º then the JPX PW is more workable right? I thought that was why the lofts on modern GI irons was reduced, to basically cancel out that increase in delivered loft. Even then my gut feel is that the increase in delivered loft for this example is less than 5º but I don't have any hard data on this.

[noSnowman]

Blade or cavity back only matters when you miss the center of the clubface.  Either way, you are hitting a round object with a flat object draw/fade is determined by path, so how the mass is positioned on the back of the clubhead really makes no difference.

have not read all the post yet but short irons are more difficult to work. I have started with blades never hit nothing else. Lack of practice and play makes me want to try some cb irons.

[rehmwa]

I don't think discussing clubs with different lofts is a good way to get at the question.   That's a good topic, and relates to spin dynamics, but it's a different topic.

It's about a blade material distribution vs a big ol' cavity with perimeter weighting and a weight balance lower.

anything else, you'd want to assume the same, same loft, etc.

Lower Center of Mass in a GI vs a blade:

- For controllability, that lower CG makes sense....if one can't visualize this bullet, no need to read further

- For workability - Iacas notes that the lower CG also translates into less side spin (as a proportion of the total spin) - so that applies.

Shape of the material distribution - GI has weight in a frame, with a thinner center area - blades are more uniform and the weight is pretty much centered

- So the CI impact can model a membrane with a stiff frame

- the blade is more of a direct hit and solid surface - it won't deform as much in the middle when striking a ball

--- controllability - for a GI, a strike off center, particularly, low on the surface (thinner shot), that membrane will deflect more and distort to give a little more loft - a blade won't do that

--- workability - (less about workability, more about what happens on an off center hit) - I'd think we might just have a GI distortion that actually adds more push or pull as a result, but would decrease the side spin associated vs same strike or mishit on a blade.  in short - the deflection of a GI club tends to square the face up through slight distortion - tiny, but relative to a blade, absolutely

Short answer, GI's will distort on impact more.  so the whole flat surface/round object is not as direct a discussion as it is when talking blades.

this is a metal club head vs a relatively softer ball, so the distortions of the club face are subtle, it's just a matter that on a GI they are less subtle than what's going on with the blades

[M2R]

I spent some time trying to understand D-plane, spin loft, spin axis, and how they interact to create (describe?) ball flight.  I was a bit surprised by what I discovered as it got more complicated than planned. I had previously been thinking of these things in rather simplistic ways.  Apparently even things like what the shaft is doing at the moment of impact, what the player is doing with their hands, and ??? can have some (small?) impact to how the ball ultimately travels thru the air.

Since I couldn't work it out to my satisfaction in the end I decided at my skill level and the conditions given by the OP I would not realistically be hampered to draw/fade on command with a GI iron. More than that I feel like I gained an appreciation for how carefully worded, well organized, and thoughtful the OP was so kudos to Johnny for that.

[virtuoso]

Ok, so we are talking left and right movement. Very interesting.

There are a couple considerations: on the one hand, you have the mass properties of the head design--and how they interact with the ball, and then you have the player's intent at delivery. How does the torque he supplying to the head determine the impact angles?

A true muscleback with minimal offset actually tends to have more draw bias than a long (heel to toe) cavity back with minimal offset, assuming same shaft, lie angle, etc. The rotational torque supplied by the golfer to the grip (the twist type torque, not un-hinge torque) will naturally speed the closure rate of the muscleback because of the smaller MOI. Also, the longer head will droop more, causing the face normal to point more to the right (remember, we have the same lie angle).

have to go work, to be continiued...

[saevel25]

Originally Posted by virtuoso

Ok, so we are talking left and right movement. Very interesting.

There are a couple considerations: on the one hand, you have the mass properties of the head design--and how they interact with the ball, and then you have the player's intent at delivery. How does the torque he supplying to the head determine the impact angles?

A true muscleback with minimal offset actually tends to have more draw bias than a long (heel to toe) cavity back with minimal offset, assuming same shaft, lie angle, etc. The rotational torque supplied by the golfer to the grip (the twist type torque, not un-hinge torque) will naturally speed the closure rate of the muscleback because of the smaller MOI. Also, the longer head will droop more, causing the face normal to point more to the right (remember, we have the same lie angle).

have to go work, to be continiued...

Well i think that's true for slice or draw with a smaller MOI. I don't think its primarialy draw basis. I think better players play a draw more often, so it might be just the fact that minimum offset is used by them more than large offset, so its skewed towards that side.

But, actually wouldn't a cavity back be easier to close because they move the weight of the club to the perimiter. Ping has a weight plug in the toe of the iron, and took a notch of weight out of the hozel.

[virtuoso]

Originally Posted by saevel25

Well i think that's true for slice or draw with a smaller MOI. I don't think its primarialy draw basis. I think better players play a draw more often, so it might be just the fact that minimum offset is used by them more than large offset, so its skewed towards that side.

But, actually wouldn't a cavity back be easier to close because they move the weight of the club to the perimiter. Ping has a weight plug in the toe of the iron, and took a notch of weight out of the hozel.

Yes, a smaller MOI is easier to start rotating and stop rotating, so the intent to manipulate closure rate is easier in either direction with a small MOI muscleback, BUT if you were to get used to the timing of a longer blade with small offset, and then suddenly picked up a short muscleback, I wouldn't be surprised to see you hit pulls/draws until you squared away the timing.

Ping is displacing the weight toward the toe to move cg more toeward, but they are probably doing it to place it more inline with where they think people are likely to hit the face. They are not doing it to speed up closure rate, because a more toeward cg does not speed up closure rate.

Now, large game improvement irons come with a ton of offset. Why? Because a that type of length clubhead, with that low, toeward cg would be very difficult to square up otherwise.

Even with that large amount of offset, many high handicap golfers still can't square the face. That is why "standard" lie angles have become more upright--to allow for the extra droop form the clubhead length and toeward cg, and to get the face normal to point lees to the right. It is definitely a good trade off based on where high handicapppers hit it on the face (thin toe with shallow angle of attack).

BUT, every now and again, you get a high handicaper who hits everything in the heel and has a steep enough angle of attack to get the hit location higher on the face. He even occasionally shanks the ball. He actually does fine with MB blades because his hit location pattern is closer to the muscleback heelward cg compared to a GI iron......and he actually squares the face up easily.

...then, of course, he misinterprets what's happening and says,"Wow, it turns out I really like the feel of FORGED clubs." LOL