GC2 launch angle

[trumb1mj]

I'm plugging my GC2 numbers into the Flightscope Trajectory Optimizer and getting wildly different peak height results.

Here are my GC2 numbers:

Ball speed: 155
Launch angle: 10.5
Total spin: 2005
Carry: 270.2
Total: 300.7
Peak height: 86.5'

When I plug these into the Flightscope Trajectory Optimizer I get a peak height of 55'.

What is throwing this off? Does GC2 use a variation of launch angle I'm not familiar with? Thanks in advance!

[goatbarn]

Altitude not at sea level?

The numbers generated by the Flightscope Optimizer are much more expected for the launch conditions given. Carrying 270 yd with only 155 BS can only happen (at sea level) if you launch the ball at 17* with same spin.

Something isn't right.

[trumb1mj]

Agreed. I think the GC2 is reporting incorrect launch angle or my understanding of the number being reported is incorrect. Does anyone have experience with the GC2 that can help? Is there an altitude setting?

[js1010]

there is no altitude setting that users can adjust that I have ever found.

One thing to note when you are looking at your carry numbers from within the simulation software (especially course play). The software will take the elevation of the hole you are hitting on in to account, so if you are hitting down hill the carry will be longer. If you are trying to see how far you hit a particular club then use the foresight range (because it pretty flat) or the GC2 itself with no software running.

that being said, I think in your case you are seeing the issue I have posted about before. Very Low back spin shots (like yours) the carry is over estimated. I tend to hit up on my driver and get very low 2000's spin and I find the carry long too long as well.

Let them know - give them the numbers you posted and say there is no way this could carry 270.

[trumb1mj]

The most unrealistic part of this simulation is the launch angle. A shot with a 10.5* launch would need to be traveling 190 MPHs to reach a peak height of 88'.

[js1010]

I would be curious to know if you do launch it at 10.5 regularly. As Goat said, it would take a much higher launch with rest of numbers the same to get 270 .

If it was a misread on this one shot and you really launch it at 15-17 then you could get around 270 carry.

[trumb1mj]

Those were averages from my session. With a ball speed of 155 and peak height of 87', these carry yardages are not out of question. The nutso part is the launch angle. Makes no sense at all. I'm contacting foresight now to see what they say.

[HoganWoods]

I'm curious about this as well. I noticed a similar problem a few weeks back. The carry numbers vs ballspeed don't make sense at times.

[john8888]

the online tool also looks at spin axis ... and it is not clear if you should be entering total spin or backspin before spin axis.

so we may not be looking at apples to apples?

[syhlif32]

There is no such thing as side spin or back spin. Those are words invented to make is easier to grasp and compare.
There are spin (Total spin) and spin axis.
You need to convert your back spin and side spin into total spin and spin axis to use the Flightscope Optimizer.

[bubs3141]

how do you convert?

[syhlif32]

Hope this makes sense?

Spin axis = Tan-1 * (Side spin/ back spin) ' tan-1 is Inv Tan' on some calculators'
Total spin = Back spin / Cos(spin axis) = Side spin /Sin( Spin axis)

To go the other way.
Back spin = Total spin * Cos(spin axis)
Side spin = Total spin * Sin(spin axis)

There is a spread sheet floating on the internet that does the conversion fort and back but can't locate it right now

[bubs3141]

thanks