Trackman and Gear Effect

[ballaholic]

I am under the impression that face angle and path readouts on Trackman are not inflenced by gear effect. I know that ballflight is going to be influenced by gear effect, but the face and path readouts are not influenced by gear effect.

In other words, if you get a reading from Trackman that says you hit a shot with 0 degrees (square) face and 0 degrees (square) path, those numbers are accurate and not affected by some kind of interpretation that factors in gear effect.

Assuming that's correct.....

My question is related to how you guys are getting info related to gear effect? Do you basically use it to vaguely explain everything other than the expected ballflight based on angle of attack, face angle, path? Or can we go a little deeper and find out more stats related to gear effect specifically?

When I first got on Trackman, with pretty much all clubs from 7i through driver, there were some shots I couldn't explain prior to learning about gear effect. Path 1 degrees in-to-out, face 3 degrees open, and a hook??? Now I understand that gear effect from a bad toe hit can explain why this wasn’t a push fade. But are there more specific details that can help with understanding gear effect spin versus spin from a differential between face/path/AoA??

 

[mgranato]

Start reading on page 4.

 

[Kevin Shields]

If you get those readings you can safely assume a toe hit

 

[ballaholic]

Start reading on page 4.

Yes - I've read it. And the missing specifics from Trackman is what I'm asking about. It's not covered there other than to say that "gear effect caused it" --

We can probably all agree that perfectly square impact in the exact middle of the face is impossible to do with regularity unless your name is Ben Hogan, and he isn't getting on the device any time soon. So there is a major need to know the impact spot on the clubface as it relates to the data. Think of it this way... what if one of the screens within Trackman's software gave you the shot trajectory for a perfectly square hit (faint dotten line), and then gave the trajectory based on what you did with your off-center hit. There could be an image of where on the face you hit the ball. Would help a lot, right? (Note I believe this isn't possible with current 3D doppler system built in there)

It's obvious I hit it on the heel badly if I swing 2 degrees outside-in with a 4 degrees shut face and look up to see a ball falling to the right. It's obvious that if I hit a smother hook and the path and face were normal that I must have hit the toe badly. However, in other less obvious scenarios especially with positive and negative AoA it would be very helpful in shining a light on what really happened.

Maybe it's an OCD obsession for the exact perfect data and explanation of strike and effect, and overkill. But then again, Trackman's entire appeal has been related to giving you the most in terms of precision...

By the way for the record I love Trackman and have been saving to buy one for practice - much to my wife and accountant's dismay.

 

[ballaholic]

If you get those readings you can safely assume a toe hit

Unless I'm mistaken, 99.9% of all shots are going to be slightly off the heel or toe and slightly high or low... so it might be helpful to get more precise data around that, including the precise effect that the less-than-perfectly-square hit had on your ball. It's funny how everybody glams on to face and path and AoA when gear effect has a massively powerful effect on ballflight - often much more than face/path/AoA. But then again I am not a PGA pro and just a low single digit guy who doesn't hit the middle of the face every time.

P.S. - Love this site and not trying to start trouble - just enjoy the discussion

 

[bryan@nobackswing.com]

i've used impact spray on my clubface when using a Trackman and was shocked at how much an off-center hit would affect ball flight with my driver. swings i used to think were way outside-in and looked like slices were good swings, just hit off the heel.

 

[Frans@France]

If you want the exact impact spot buy some deadon markers and then hit those shots again or use the performance studio software and trace the ball position at impact from the (highspeed) video.

Or just look at the spin axis tilt data from the TM and compare that to the path/face difference

 

[Kevin Shields]

Yesterday, "not to complicate things more", Tuxen said there is an element to dead center contact that really doesn't make it react like dead center contact.


Tough game.

 

[leon]

I am under the impression that face angle and path readouts on Trackman are not inflenced by gear effect. I know that ballflight is going to be influenced by gear effect, but the face and path readouts are not influenced by gear effect.

In other words, if you get a reading from Trackman that says you hit a shot with 0 degrees (square) face and 0 degrees (square) path, those numbers are accurate and not affected by some kind of interpretation that factors in gear effect.

Assuming that's correct.....

My question is related to how you guys are getting info related to gear effect? Do you basically use it to vaguely explain everything other than the expected ballflight based on angle of attack, face angle, path? Or can we go a little deeper and find out more stats related to gear effect specifically?

When I first got on Trackman, with pretty much all clubs from 7i through driver, there were some shots I couldn't explain prior to learning about gear effect. Path 1 degrees in-to-out, face 3 degrees open, and a hook??? Now I understand that gear effect from a bad toe hit can explain why this wasn’t a push fade. But are there more specific details that can help with understanding gear effect spin versus spin from a differential between face/path/AoA??

Great question. You should ask it at the Anti..... oh.

 

[birly-shirly]

Gear effect in irons is much reduced compared to woods, yes?

Is gear effect on irons sufficient to produce a toe-hook, or a heel-cut?

 

[Todd Dugan]

I use this chalk spray in just about every lesson. golf training aids, training aids, golf training aids - On-Mark Impact Spray
It doesn't affect the collision the way decals do. But you MUST know where the ball is striking the clubface if you are making an analysis of path and clubface based on the ball flight......with or without a TrackMan. Once you've got your path and face "pattern" worked out fairly well, the biggest cause of ball flight errors is off-center impacts.

 

[mgranato]

Think of it this way... what if one of the screens within Trackman's software gave you the shot trajectory for a perfectly square hit (faint dotten line), and then gave the trajectory based on what you did with your off-center hit.

Love this idea. I know two guys who were in recent TM Newsletters who could probably make this happen.

By the way for the record I love Trackman and have been saving to buy one for practice - much to my wife and accountant's dismay.

Yah, but wait until they see that club champion trophy walk through the door... then they'll understand!

 

[ballaholic]

Gear effect in irons is much reduced compared to woods, yes?

Is gear effect on irons sufficient to produce a toe-hook, or a heel-cut?

Reduced yes... But still extremely important and a major source of confusion. From their data, a 170 yard 6-iron hit 1/2 inch toward the toe but with 0 degree face and path still went 24 feet left of target. We need AoA to determine exactly how much the gear effect contributed, but that's just a 170 yard 6i.

I hit mine 190-200 and the gear effect increases exponentially as a result. And then there's the 5i, 4i, 3i etc... All with increasing gear effect issues.

On Trackman I've definitely hit 7i shots with good face, path, AoA numbers that were wiped out by gear effect.

For a large part of the golfing population, perhaps the average 3 to 13 handicap who has a reasonably consistent path, the most important element in diagnosis and improvement is going to be training on how to hit the center of the face repeatedly. Consistent path is huge, but after that there is a problem in trying to work on face angle without knowledge of gear effect because you will be working off of bad data/assumptions/instincts. Chasing a hook problem by opening the face relative to path is a DISASTER if the problem is toe hits rather than face angle.

 

[Frans@France]

Reduced yes... But still extremely important and a major source of confusion. From their data, a 170 yard 6-iron hit 1/2 inch toward the toe but with 0 degree face and path still went 24 feet left of target. We need AoA to determine exactly how much the gear effect contributed, but that's just a 170 yard 6i.

I hit mine 190-200 and the gear effect increases exponentially as a result. And then there's the 5i, 4i, 3i etc... All with increasing gear effect issues.

Don't know why you need the AoA?

In general (it depends on the clubhead design (or better cog postion) a 1/2 inch mishit with an iron6 will generate a 7degree axis tilt due to gear effect.

If the shot was 100% square/square then that 170yards and 7degree tilt will generate a 8.33 yards curve.

Rule of thumb is that every 10degree axis tilt will give you 7% of the carry as the curve.

So with the same gear effect (or axis tilt) of 7degree but a carry of 200 you will curve it 9.8 yards

 

[birly-shirly]

Reduced yes... But still extremely important and a major source of confusion. From their data, a 170 yard 6-iron hit 1/2 inch toward the toe but with 0 degree face and path still went 24 feet left of target. We need AoA to determine exactly how much the gear effect contributed, but that's just a 170 yard 6i.

I hit mine 190-200 and the gear effect increases exponentially as a result. And then there's the 5i, 4i, 3i etc... All with increasing gear effect issues.

On Trackman I've definitely hit 7i shots with good face, path, AoA numbers that were wiped out by gear effect.

For a large part of the golfing population, perhaps the average 3 to 13 handicap who has a reasonably consistent path, the most important element in diagnosis and improvement is going to be training on how to hit the center of the face repeatedly. Consistent path is huge, but after that there is a problem in trying to work on face angle without knowledge of gear effect because you will be working off of bad data/assumptions/instincts. Chasing a hook problem by opening the face relative to path is a DISASTER if the problem is toe hits rather than face angle.

Wow. I've got to be honest. I think I understood the principle of gear effect in woods, but I didn't think the effect would be so pronounced in irons. My uneducated guess would have been that, with irons, toe hits would start right and curve right due to the face opening at impact. And vice versa off the heel.

Does this happen across all iron designs? Or are toe hooks limited to back-weighted iron designs?

 

[Frans@France]

Wow. I've got to be honest. I think I understood the principle of gear effect in woods, but I didn't think the effect would be so pronounced in irons. My uneducated guess would have been that, with irons, toe hits would start right and curve right due to the face opening at impact. And vice versa off the heel.

euh....the gear effect is that the face opens (to the right for right-handed) and the ball spin axis tilts the other way!

Does this happen across all iron designs? Or are toe hooks limited to back-weighted iron designs?

The amount of gear effect depends on the distance from the face and the Cog rearwards position.

 

[ballaholic]

Wow. I've got to be honest. I think I understood the principle of gear effect in woods, but I didn't think the effect would be so pronounced in irons.

In a lot of on-the-course situations, the gear effect in irons is far worse for your scoring than the gear effect of woods. My course and many others have a lot of room to miss off the tee and still recover. But missing your iron shot 20-30 feet due to gear effect will often leave you in a disastrous situation beside the green.

 

[Frans@France]

the gear effect in irons is far worse for your scoring than the gear effect of woods.

The gear effect is much greater on woods then on irons due to the cog being more readwards but the woods have bulge and the bulge will make sure that the ball returns as much as possible to the center line. That bulge is missing on the irons.

 

[ballaholic]

I should have been more clear - the gear effect in terms of physics is worse with woods. Bulge helps but obviously with woods there is more gear effect. However depending on course design and pin placement, the gear effect's effect on scoring can often be worse with irons because gear effect exists with irons and you may be fitting a shot into an area with very little room for error.

 

[Todd Dugan]

When you impact an iron on the toe, the face twists open. This would normally tilt the spin axis way to the right as the clubface is well open to the path during collision. The proof that gear effect exists with irons is that toe impacts don't usually slice. But the effect in irons is not strong enough to actually cause a toed impact to hook, as it will with woods. Rather, with irons, toes tend to just push straight right and heels pull straight left.... a little. What would fix this is a concave clubface, but that is illegal. The gear effect is so strong with woods, that a convex clubface "corrects" ball flight, which is obviously legal.

The study of off-center hits and gear effect is trickier than it appears on the surface. The very best, definitive material on this is found in "Search For The Perfect Swing". Years ago, I thought that I really understood gear effect. Years later, I realized that I needed to study that chapter much more closely, which I have since done.