Minimum swing speed for ProV1 or ProV1x

[acerimusdux]

2 hours ago, iacas said:

 The performance in that one chart shows how little the difference is across a really wide range of swing speeds:

The differences there are minimal.

 

Thanks, I wanted to post that chart, couldn't get it to work. But that shows also, C.O.R. is actually higher at the lower speeds, and so the most efficient energy transfer is occurring at those speeds. So it isn't needed to deform or "compress" these balls a certain amount in order to get efficient energy transfer.

I'm speculating that firmer=faster might be true of the kind of material used in the core if it were allowed to be engineered for maximal speed and distance. I think the lower C.O.R. at higher speeds there is by design, in order for balls to remain conforming. The standards generally apply at the equivalent of high swing speeds.

 

[iacas]

1 hour ago, acerimusdux said:

Thanks, I wanted to post that chart, couldn't get it to work. But that shows also, C.O.R. is actually higher at the lower speeds, and so the most efficient energy transfer is occurring at those speeds. So it isn't needed to deform or "compress" these balls a certain amount in order to get efficient energy transfer.

Yes. More deformation means more lost energy.

1 hour ago, acerimusdux said:

I'm speculating that firmer=faster might be true of the kind of material used in the core if it were allowed to be engineered for maximal speed and distance. I think the lower C.O.R. at higher speeds there is by design, in order for balls to remain conforming. The standards generally apply at the equivalent of high swing speeds.

I think it's just physics. More deformation means more energy lost.

[acerimusdux]

5 hours ago, iacas said:

Yes. More deformation means more lost energy.

I think it's just physics. More deformation means more energy lost.

Yes, but you would think the firmer material would deform less. But it still isn't losing any less energy. 

So the difference must be in the elasticity of the materials. It's not a universal law that more deformation will lead to more energy loss. A more elastic material can deform more while losing less energy.

For example, carbon fiber composites are stronger and lighter weight than titanium alloys. But they wouldn't be used in a driver face, mainly because they don't have the elasticity of titanium alloys. For that matter, the titanium alloy face is usually made very thin. Why? Because then it will be more flexible. A thinker face would deform less, but would then produce less spring effect and less ball speed. In fact, beta titanium is no longer used very often in conforming heads, because COR limits mean that a very thin face would exceed limits, and thus the face would have to be made thicker than normally desired for weight distribution reasons. So somewhat stiffer titanium alloys are used today that can be made thinner while staying within limits. 

I'm just saying something similar is probably occurring with balls. They likely could make firmer balls today that produced higher ball speed, but they would no longer be conforming.  So conforming low compression balls now perform about the same as conforming high compression balls (for ball velocity).

Edited January 25, 2017 by acerimusdux

[Lihu]

8 minutes ago, acerimusdux said:

Yes, but you would think the firmer material would deform less. But it still isn't losing any less energy. 

So the difference must be in the elasticity of the materials. It's not a universal law that more deformation will lead to more energy loss. A more elastic material can deform more while losing less energy.

I'm not a materials expert, but it seems like deformation is mostly internal energy.

The ball bounces back to approximately its original form, but some of the energy used to deform it is still inside the material and eventually dissipated? That's a complete loss as far as converting it to forward kinetic energy?

Unfortunately not much has been written about the golf impact, and this is the only article that I could find on this subject.

110004155945.pdf

Anything substantial is probably proprietary to Titleist, Bridgestone and all the other ball makers?

[1badbadger]

11 hours ago, No Mulligans said:

My experience has been that soft vs. firm (say an E6 vs. a ProV1, both of which I often play), ... the increased "straightness" of the softer ball is pretty negligible.  I've hit plenty of banana slices with both the E6 and the ProV1.  To make either of them go pretty straight, I have to hit the ball well... I've hit plenty of straight balls with the E6 and the ProV1s.  I'm thinking the "helps you hit it straighter" marketing is a bit overblown.  Are there any robo-swing analysis to this point?

In player testing and fittings the e6 is 31% straighter on average.  Because of all the variables, it will vary from player-to-player.

[1badbadger]

3 hours ago, Lihu said:

I'm not a materials expert, but it seems like deformation is mostly internal energy.

The ball bounces back to approximately its original form, but some of the energy used to deform it is still inside the material and eventually dissipated? That's a complete loss as far as converting it to forward kinetic energy?

Unfortunately not much has been written about the golf impact, and this is the only article that I could find on this subject.

110004155945.pdf

Anything substantial is probably proprietary to Titleist, Bridgestone and all the other ball makers?

If everyone wasn't confused yet, this oughta do it...

Another aspect to consider is cover thickness.  Ball speed and backspin are inversely related in regards to cover thickness.  Thick covers produce less ball speed but more backspin and thin covers have higher ball speed but less spin.  This is because the cover is a lower C.O.R. material than the core, so thicker covers will have less ball speed.

Cover stiffness also has a trade-off.  A softer cover will spin more, but it will reduce ball speed.  The thing is, the trade-off between spin and ball speed isn't equal.  Cover stiffness has a bigger effect on spin than it does on ball speed.  Cover thickness has a bigger effect on ball speed then it does on spin.

[acerimusdux]

10 hours ago, Lihu said:

I'm not a materials expert, but it seems like deformation is mostly internal energy.

The ball bounces back to approximately its original form, but some of the energy used to deform it is still inside the material and eventually dissipated? That's a complete loss as far as converting it to forward kinetic energy?

It depends on the elasticity. In a perfectly elastic collision, where the material immediately returns to it's prior shape, there is no energy lost. But that probably exists only in theory.

In reality the ball does likely incur some internal deformation which doesn't immediately bounce back, and which leads to some loss of energy. In fact, the reason more deformation is good for the driver face may be that this causes less deformation of the ball (and less energy loss). 

But the amount of deformation alone can't tell you which ball is losing more energy, if comparing different materials.

 

[iacas]

14 minutes ago, acerimusdux said:

It depends on the elasticity. In a perfectly elastic collision, where the material immediately returns to it's prior shape, there is no energy lost. But that probably exists only in theory.

We often treat collisions among gas atoms or molecules as being elastic because they're so darn close that it's a good approximation, but outside of something we don't know yet, yeah, I think it's more the realm of theory if you're incredibly precise about it.

14 minutes ago, acerimusdux said:

In reality the ball does likely incur some internal deformation which doesn't immediately bounce back, and which leads to some loss of energy.

And sound, and heat.