Effects of 1* loft difference on 7i

[wundej]

General question as I’m trying to sort some things out with my irons. I’m curious what some of the experienced fitters have seen over the years. 
 

Assuming all things equal (head, chs, AoA, path, impact location), what would you expect the difference in ball speed and potentially spin be from a 30* iron vs a 31* iron. I realize a lot is relative to the head design, but in general, what percentage difference would you expect in ball speed/launch/spin be?

 

I’m debating on what to do with some irons that didn’t seem to pan out the way I expected. They are about a degree weaker than I usually play and before bending (or moving onto something else) I wanted some feedback from the gurus here. 
 

Thanks for the feedback.

Edited October 9, 2020 by wundej

[skraly]

It’s doubtful unless you have the consistency of contact of a +4 to +5 handicap that you would notice any difference at all. 

[Golfrnut]

About 200 rpm and maybe a mph of ball speed diff.  Much of depends on club head speed. 2 yards +-  

[2bGood]

9 minutes ago, Golfrnut said:

About 200 rpm and maybe a mph of ball speed diff.  Much of depends on club head speed. 2 yards +-  

Sounds about right. 

[golffeen007]

26 minutes ago, Golfrnut said:

About 200 rpm and maybe a mph of ball speed diff.  Much of depends on club head speed. 2 yards +-  

Few variables , but this is a good scenario. Maybe 3 yards , other differences , doubtful would be noticed.  

[wundej]

58 minutes ago, Golfrnut said:

About 200 rpm and maybe a mph of ball speed diff.  Much of depends on club head speed. 2 yards +-  

Thanks, that’s about what I was guessing. Wasn’t sure if anyone had some real world data that might map over to a rough % change across a few different swing speeds. Obviously you can’t just look at mph differences since as CHS goes up, the gap between original and 1* strong will grow. 
 

All that being said, if I get a few yards closer to my distances on my previous set and dispersion is better along with descent angle still being steeper (I know this will change too), might be worth it. 

[Golfrnut]

That basically comes from the launch monitor makers that supposedly do all that kind of scientific stuff. 

[Trav29]

Just tested this on the same 6 iron hit 10 shots and then bent it 2deg. Then hit ten more shots. The difference was 9 yards total average And 1330 spin. So I’d say it’s fair to say 4.5 yards and 665rmp of spin per degree stronger.

[golffeen007]

2 minutes ago, Trav29 said:

Just tested this on the same 6 iron hit 10 shots and then bent it 2deg. Then hit ten more shots. The difference was 9 yards total average And 1330 spin. So I’d say it’s fair to say 4.5 yards and 665rmp of spin per degree stronger.

🤨 9yrds and 1330 spin from 2 degrees? We're talking carry yards or total?

[Trav29]

Just now, golffeen007 said:

🤨 9yrds and 1330 spin from 2 degrees? We're talking carry yards or total?

Total 

[Trav29]

I’d like to hear more on this from anyone who has tested this as well?

Edited October 10, 2020 by Trav29

[Trav29]

21 minutes ago, Trav29 said:

Total 

 

23 minutes ago, Trav29 said:

Total 

 

24 minutes ago, golffeen007 said:

🤨 9yrds and 1330 spin from 2 degrees? We're talking carry yards or total?

Update:

This may be more accurate over a wider range of data....Looked at my Arccos stats. (7500shots)

4 degrees of difference between by 7 and 6i equal to 13 yards. So 3.25yards for every degree

[Smokey227]

10 minutes ago, Trav29 said:

 

 

Update:

This may be more accurate over a wider range of data....Looked at my Arccos stats. (7500shots)

4 degrees of difference between by 7 and 6i equal to 13 yards. So 3.25yards for every degree

There is the 1/2” of length difference that also adds into the equation between your 6 and 7 that doesn’t exist when simply bending a club. 

Edited October 10, 2020 by Smokey227

[Golfrnut]

13 minutes ago, Trav29 said:

 

 

Update:

This may be more accurate over a wider range of data....Looked at my Arccos stats. (7500shots)

4 degrees of difference between by 7 and 6i equal to 13 yards. So 3.25yards for every degree

 

so how do you think that works when most only see 10 yds +- in yardage gaps between clubs when they have 3-4* of difference and 1/2” lengths?  
 

Aarcos is not the way to go about that...

Edited October 10, 2020 by Golfrnut

[Trav29]

14 minutes ago, Golfrnut said:

 

so how do you think that works when most only see 10 yds +- in yardage gaps between clubs when they have 3-4* of difference and 1/2” lengths?  
 

Aarcos is not the way to go about that...

So tell me how do you go about that? Cause I literally did the test on gc2

[VCGolfer79]

Bend it and hit it. Should get some good info off of that haha

[wundej]

Thanks for the test, but for any real data to analyze, it would have to be on a launch monitor that can give enough info to assume a decent sample of similar impact conditions. 
 

Impact location 

CHS

Launch angle

Dynamic loft or AoA

path/face angle would be good too, just to try to measure square contact. 
 

We’d need to pick similar shots to get any real info. Then we could see the ball speed difference (yards are all relevant to ball speed) between the loft change, as well as spin. Really just need an Iron Byron and a GC2. 

[wundej]

5 minutes ago, Trav29 said:

So tell me how do you go about that? Cause I literally did the test on gc2

Just saw this. Did you happen to do this on FSX and have the session data available? Would really be interested in the ball speeds and see the launch conditions. 

[Golfrnut]

13 minutes ago, Trav29 said:

So tell me how do you go about that? Cause I literally did the test on gc2

 

same way he just stated above. Too many variables to be had. If it were a controlled test, you’d see gaps in the neighborhood of 20+ yards if loft made that much of an impact.  That’s just not what is seen in reality. Guys that have those kinds of gaps that are hitting clubs properly have a lot of swing speed to do so.  They would be the exception, not the norm. 

Edited October 10, 2020 by Golfrnut

[Trav29]

8 minutes ago, Golfrnut said:

 

same way he just stated above. Too many variables to be had. If it were a controlled test, you’d see gaps in the neighborhood of 20+ yards if loft made that much of an impact.  That’s just not what is seen in reality. Guys that have those kinds of gaps that are hitting clubs properly have a lot of swing speed to do so.  They would be the exception, not the norm. 

Fair enough maybe I need to state I’m a +1.0 and swing a 7 i at 95mph, I’m just stating what I found. 

[Golfrnut]

8 minutes ago, Trav29 said:

Fair enough maybe I need to state I’m a +1.0 and swing a 7 i at 95mph, I’m just stating what I found. 

Trackman put out lab produced numbers years ago. At 100 MPH club head speed, 1* of loft change is worth about 250 RPM. As you go up in CHS, it goes up a little, and as you go down in CHS, that spin rate difference goes down. 
 

edit: should also point out, those figures are for driver loft...which has more of an influence on the ball than the irons do. 

Edited October 10, 2020 by Golfrnut

[Trav29]

6 minutes ago, Golfrnut said:

Trackman put out lab produced numbers years ago. At 100 MPH club head speed, 1* of loft change is worth about 250 RPM. As you go up in CHS, it goes up a little, and as you go down in CHS, that spin rate difference goes down. 

Then congrats you just answered his question !!! All that is relative when you’re dealing with higher spinning head designs and shafts, the way someone delivers a club etc. There’s no one size fits all. If I need to repeat myself All I am saying is What I found.

[wundej]

7 minutes ago, Trav29 said:

Then congrats you just answered his question !!! All that is relative when you’re dealing with higher spinning head designs and shafts, the way someone delivers a club etc. There’s no one size fits all. If I need to repeat myself All I am saying is What I found.

I appreciate you giving it a try. Is there any chance you had the data in FSX that you could pass on? Not sure if you had HMT as well, but would love to see the data, even if it’s just ball data. Can get enough info to make some real judgments and assumptions about what the club was doing. As expected though, with higher chs, the impact is more substantial. 

[Howard_Jones]

double post.... deleted

Edited October 10, 2020 by Howard_Jones

[Howard_Jones]

9 hours ago, wundej said:

General question as I’m trying to sort some things out with my irons. I’m curious what some of the experienced fitters have seen over the years. 
 

Assuming all things equal (head, chs, AoA, path, impact location), what would you expect the difference in ball speed and potentially spin be from a 30* iron vs a 31* iron. I realize a lot is relative to the head design, but in general, what percentage difference would you expect in ball speed/launch/spin be?

 

I’m debating on what to do with some irons that didn’t seem to pan out the way I expected. They are about a degree weaker than I usually play and before bending (or moving onto something else) I wanted some feedback from the gurus here. 
 

Thanks for the feedback.

Spin is related to club speed,  but if we use a PGA average numbers, 1* loft is 201 rpms spin. (average change for #6-#7-#8), and for ball speed we are right below 1 mph for each *1, so if we say 1 mph and 200 rpms we want be far off as a "rule of thumb" since this vary a bit trough the bag, its NOT a constant factor. (se below)

We say distance between irons is 80% loft and 20% club speed, and since the average loft difference is 4* we have 5 equal parts here, where 4 of them is loft the last is club speed, so if a player has lets say 11 yards carry difference from club to club, we can simply take 11 / 5 = 2.2 yards from club speed, and 2.2 yards for each 1* of loft.

The average PGA numbers from #5 iron to #8 looks like this ( i left out the #4 since it could be only 3* loft difference in some sets from #5 to #4)

#5 to #6 = plus 862 rpms
#6 to #7 = plus 756 rpms
#7 to #8 = plus 795 rpms

Average change is 201 rpms for each 1* of loft, assuming they all have 4* as loft gaps as average in this 3 clubs.

For launch angle, we use 50* of loft change, so 1* difference to loft becomes 0.5* difference to launch angle (this is average for irons, for the driver we use 0.84* as average, so its no constant here either)

Edited October 10, 2020 by Howard_Jones

[wundej]

1 hour ago, Howard_Jones said:

Spin is related to club speed,  but if we use a PGA average numbers, 1* loft is 201 rpms spin. (average change for #6-#7-#8), and for ball speed we are right below 1 mph for each *1, so if we say 1 mph and 200 rpms we want be far off as a "rule of thumb" since this vary a bit trough the bag, its NOT a constant factor. (se below)

We say distance between irons is 80% loft and 20% club speed, and since the average loft difference is 4* we have 5 equal parts here, where 4 of them is loft the last is club speed, so if a player has lets say 11 yards carry difference from club to club, we can simply take 11 / 5 = 2.2 yards from club speed, and 2.2 yards for each 1* of loft.

The average PGA numbers from #5 iron to #8 looks like this ( i left out the #4 since it could be only 3* loft difference in some sets from #5 to #4)

#5 to #6 = plus 862 rpms
#6 to #7 = plus 756 rpms
#7 to #8 = plus 795 rpms

Average change is 201 rpms for each 1* of loft, assuming they all have 4* as loft gaps as average in this 3 clubs.

For launch angle, we use 50* of loft change, so 1* difference to loft becomes 0.5* difference to launch angle (this is average for irons, for the driver we use 0.84* as average, so its no constant here either)

This is the general type of breakdown I was looking for.  Obviously it won’t 100% translate to an amateur, but the details about breaking it down by length / loft contributors makes sense, given somewhat consistent spin changes w/loft. 
 

Thanks for the detailed breakdown. I’m sure a few learned a bit here. Very helpful. 

[Howard_Jones]

36 minutes ago, wundej said:

This is the general type of breakdown I was looking for.  Obviously it won’t 100% translate to an amateur, but the details about breaking it down by length / loft contributors makes sense, given somewhat consistent spin changes w/loft. 
 

Thanks for the detailed breakdown. I’m sure a few learned a bit here. Very helpful. 

You would have found this "split" if you compared classic sets with Single length irons. In classic sets we use 4* as loft gaps, in SL sets the average is 5* in the "mid and short" irons, so its easy to see that shaft length / club speed is 1/5 or 20% of it all, but it becomes a "rule of thumb" only since PTR or Smashfactor changes with lofts, so in the "long end" of the set we can use less loft gaps since the change in ball speed for each 1* of loft becomes higher. PGA average say there is 5 mph ball speed difference from #3 to #4, and so is #4 to #5, and #5 to #6, but #3 to #4 is very often only 3* as loft difference.

 

[Trav29]

15 hours ago, wundej said:

General question as I’m trying to sort some things out with my irons. I’m curious what some of the experienced fitters have seen over the years. 
 

Assuming all things equal (head, chs, AoA, path, impact location), what would you expect the difference in ball speed and potentially spin be from a 30* iron vs a 31* iron. I realize a lot is relative to the head design, but in general, what percentage difference would you expect in ball speed/launch/spin be?

 

I’m debating on what to do with some irons that didn’t seem to pan out the way I expected. They are about a degree weaker than I usually play and before bending (or moving onto something else) I wanted some feedback from the gurus here. 
 

Thanks for the feedback.

I disagree a bit with Howard,you can’t put spin numbers from how many tour players in a box and sat that’s the average.....It’s relative there’s to many variables to an individual swing.

 

 No one has asked you...

what is it you’re trying to achieve in relation to your original question???? That’s where we should be helping you with.

[wundej]

43 minutes ago, Trav29 said:

I disagree a bit with Howard,you can’t put spin numbers from how many tour players in a box and sat that’s the average.....It’s relative there’s to many variables to an individual swing.

 

 No one has asked you...

what is it you’re trying to achieve in relation to your original question???? That’s where we should be helping you with.

I was really trying to see if anyone had real data on how 1* less loft affects ball speed. That’s pretty much it. Spin and launch is going to be impacted by many other factors but in general I just wanted to see if anyone had a rough percentage of difference it makes. I figured there were many fitters who make minor adjustments to lofts to fit gapping needs, so while not truly scientific, it’s real world observation that could show a trend if they’ve done it enough.
 

Simply, I have a set of irons that I get a little more ball speed/better smash factor out of (HMP) and picked up a set of new irons that are more consistent from a dispersion perspective (0311p gen2) but a mph or two less ball speed, but the loft of the 7i is 1* weaker on the 0311. Obviously they are different irons and sometimes there are concessions that need to be made for distance if you want some consistency/accuracy. I’m not super concerned about launch/spin as a little less wont hurt me too much (and my height/decent are both better than the HMP already so I have a bit to spare). 

So debating on if I want to get them bent a degree strong or leave them as is and adjust my yardages a little. 

[Howard_Jones]

1 hour ago, Trav29 said:

I disagree a bit with Howard,you can’t put spin numbers from how many tour players in a box and sat that’s the average.....It’s relative there’s to many variables to an individual swing.

 

 No one has asked you...

what is it you’re trying to achieve in relation to your original question???? That’s where we should be helping you with.

What gives you the idea that it has anything to do with "how many tour players", did i use a certain number of players in the math? and what makes you think the players swing will change if we bend lofts?´Dont you expect the player to swing like he always does?

Feel free to explain how this works