I don't under stand how I hit that ball that low, with that much dynamic loft.

[GeoffDickson]

I am a little confused by the numbers at the moment....

Club: 7 iron, Ping I20, CFS Stiff
Ball: Prov1
Mat: Real Feel
Launch Monitor: Flightscope (Indoor mode)


Clubhead speed: 89mph
Dynamic loft: 27*
Angle of Attack: -3.5*
Spin loft: 30.5
Ball speed: 120mph
Vertical launch: 19.1*
Spin rates: 8500-9000

Do these numbers make sense?

Here is how I connect the dots....My spin loft is very big....which is underpinned by a high dynamic loft. This is what creates all that spin.

Here is where I get confused....I don't understand how I hit that ball that low, with that much dynamic loft.

 

[ZAP]

It will be interesting to see the replies from the people who know a whole lot more than I do about this stuff.
Just because I am not really afraid to be wrong I want to say impact was up a bit on the face. BUT I really have no idea
because my experience with these things is limited at best.

 

[Frans@France]

I am a little confused by the numbers at the moment....

Club: 7 iron, Ping I20, CFS Stiff
Ball: Prov1
Mat: Real Feel
Launch Monitor: Flightscope (Indoor mode)


Clubhead speed: 89mph
Dynamic loft: 27*
Angle of Attack: -3.5*
Spin loft: 30.5
Ball speed: 120mph
Vertical launch: 19.1*
Spin rates: 8500-9000

Do these numbers make sense?

Here is how I connect the dots....My spin loft is very big....which is underpinned by a high dynamic loft. This is what creates all that spin.

Here is where I get confused....I don't understand how I hit that ball that low, with that much dynamic loft.

iron launch angle 75% Dynamic loft --> 27 * 0.75 = 20.25
iron launch angle 25% AoA --> -3.5 * 0.25 = -0.875
Total launch angle = 20.25 + (-0.875) = 19,375 so that 19.1* is very close.

SpinRate [rpm] ~ 2.3-3.0 * ClubSpeed [mph] * SpinLoft [deg]

3.0 * 89 * 30.5 = ~8143rpm

 

[Brian Manzella]

Clubhead speed: 89mph
Dynamic loft: 27*
Angle of Attack: -3.5*
Spin loft: 30.5
Ball speed: 120mph
Vertical launch: 19.1*
Spin rates: 8500-9000


Vertical D-Plane (Spin Loft) 30.5°

Ball should start 75% toward clubface normal (top of the D-Plane) 22.875° (of the 30.5)


3.5° of that 22.875° is getting the ball "out of the ground."


22.875° - 3.5° = 19.375°

 

[GeoffDickson]

Zap,

Good theory....but it seems that both Frans and Brian are confirming that the numbers make sense.

Looks like I just have to find a way of reducing the spin loft by 3-4* to get the spin rates down.