Launch Angle

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hbyrd
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Launch Angle

Post by hbyrd » Tue Dec 10, 2013 9:01 am

When I get on a launch monitor the salesman always tells me that my launch angle needs to be lower, usually around 13-14 degrees. However, with my swing speed (104) and playing with the numbers in Trajectoware my greatest carry distance occurs when my launch angle is 25 degrees with a back spin of 1500. So do I need to increase my launch angle or decrease it as the salesman states?

dtutelman
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Post by dtutelman » Tue Dec 10, 2013 12:07 pm

The question is: how can you get that high a launch angle with that little spin? And the answer to that questions is: you need about an 18* angle of attack. That would mean a ball teed up about 3 inches above the ground and almost a foot and a half forward of your swing bottom. Then use a driver with an effective loft around 7 degrees. (That's probably a 5* driver with an extra 2* from shaft bend.) Think you can do that? I know I can't.

If you can reliably hit the ball high on the clubface, you might get an extra degree or two and lose an extra 500rpm of spin. That's gear effect. And it's the assumption I made when I cited the 18* angle of attack. If you can't do that, if you typically hit near the middle of the clubface, you need more than 20* angle of attack, and an effective loft about 5*.

So let's get back to real-world swings with an angle of attack not far from zero. I disagree with the 13-14 degree launch angle as optimum; I think it's in the 11-12* range. But certainly not over 20*, because the only way you're going to get over 20* is with too much spin for that to be the right launch angle.

To use TrajectoWare Drive to figure this out, play with the impact conditions instead of the launch conditions. Put in a realistic attack angle; start with zero, since that is probably close -- unless know KNOW what yours is. Then play with the club's loft to maximize distance. You do it that way because loft is the big control you have for launch angle, and it also has a large effect on spin.

The moral of this story: you can use TrajectoWare Drive to answer A LOT of questions. (I used it for all the what-if calculations for this response.) But you have to be careful what question you are asking, or your answer will not be useful.

hbyrd
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Realistic Launch Angle

Post by hbyrd » Tue Dec 10, 2013 1:04 pm

I was using the software to try and find out my max distance based on my swing speed and it seemed that the higher the launch angle and the less backspin the more my distance went up. I wasn't being realistic though. I'll play with the impact conditions and see what I get. I have an 8.5 degree driver with a stiff flex shaft...what would be a realistic angle of attack, if I don't cup my wrists and I use a 2 3/4 inch tee?

dtutelman
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Re: Realistic Launch Angle

Post by dtutelman » Tue Dec 10, 2013 6:04 pm

hbyrd wrote:I was using the software to try and find out my max distance based on my swing speed and it seemed that the higher the launch angle and the less backspin the more my distance went up.
True as far as it goes. But you were finding max distance where the independent variables were launch angle and spin. They aren't independent; they have to be generated by your swing and the driver.
I'll play with the impact conditions and see what I get. I have an 8.5 degree driver with a stiff flex shaft...what would be a realistic angle of attack, if I don't cup my wrists and I use a 2 3/4 inch tee?
I'm not going to go by the driver -- but I can tell you that you'll probably have another 2* of loft due to shaft bend. (The shaft bend at impact is a guess on my part; it depends on the swing, but 2* is typical.)

The tee height is not the controlling factor. Your angle of attack will be controlled by how far forward in your stance you can place the ball and still hit it well and consistently. "Well" means you can cope with:
  • * Height of clubhead at impact. THERE is where you worry about tee height. Find the tee height (separately, for each forward position you try) by using impact tape or talcum powder to show the impact on the face.
    * No pull or slice. The forward position of the ball means that the clubhead is probably traveling to the left by the time it reaches the ball (for a RH hitter). That will give a pull or a slice. An inside-out swing can stave that off for a certain distance forward. So the forward position of the ball must give a reasonable starting direction and fade so as to be in the fairway with not much loss of distance.
    * No loss of clubhead speed. The head must be going at least as fast at impact as it was at the bottom of the swing. If the forward position of the ball means a loss of clubhead speed at impact, the process is self-defeating.
You should also know where your swing bottom is. (For many good drivers of the ball, it is around the front heel.) If you take the distance from the swing bottom to the ball, there is about a degree of attack angle for each inch. So now you know your maximum attack angle. In the process, you've learned how high you have to tee it to achieve that angle.

At this point, you may have to scrap your driver and get one whose loft is better suited to your max distance as computed by TrajectoWare Drive. (The effective loft of your current driver is about 8.5+2=10.5. I'm not sure how the shaft bend will be affected by an unusually forward ball position, so I'm not sure 2* is the right number for that.)

Bottom line: it's logical and can be done, but it is by no means an easy question to answer. That's why it takes knowledge and experience to be a good clubfitter -- not just a launch monitor and some good computer programs.

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