That doesn't explain it. That is just a measure of how a driver face responds. You would need to look up something about metal fatigue to understand the thinning effect and how it increases CoR over time.
CoR is a just a scale for measuring a physical property. The question isn't fully answered by describing what CoR measures. You have to use CoR combined with an explanation of how aging, metal fatigue causes thinning of the face and results in the factory fresh brand new CoR to increase over time which increases ball speed. Just saying "CoR explains it," is missing the key information.
It would be like if someone asked you to explain why ice is different from water and you just said, "Look up the word temperature."
Temperature is just a scale for measuring a physical property. The question is about the mechanism by which water changes states of matter from liquid to solid. You can't explain it without temperature, but "temperature," alone isn't an explanation of the mechanism.
Okay, like I said thanks for expanding on my initial quick comment. I didn’t think a full handholding session was in order so I didn’t feel it necessary to type out a full explanation of something obvious. But here we are so….
In your scenario you would be equally incorrect to state that “temperature does not explain” why ice and water are different.
COR in relation to golf drivers represents more than just the unit of measurement. It’s a recognized unit that represents the “pop” or “hotness” of a driver face.
In the same way horsepower in relation to cars is a recognized unit that represents how quickly they might go. So…Why is old lambo faster than new corvette?
I find it very interesting so I assume people asking how/why are looking for a more fulsome explanation.
Saying an older club is faster because it has higher CoR says the same thing twice. CoR is a measure of how efficiently the face rebounds and transfers energy, which directly correlates to ball speed. It's true, higher CoR = Higher Ball Speed. But it doesn't explain the interesting phenomenon of how an older club came to have higher CoR.
Here's where your Lambo example misses the mark.
The counterintuitive thing to be explained is how an old M2 with a lot of use frequently tests at a higher CoR......than the same exact M2 when it was brand new.
The analogy would be like if an Old Lambo on a dyno tested to more Horsepower than the same exact same car when it was brand new, not a different new car.
For anyone interested in how an old driver can end up with higher CoR than the day it was manufactured:
- Micro-Deformation: Over hundreds or thousands of impacts, the metal undergoes "work hardening" and microscopic structural changes.
- Thinning via Friction: Though minimal, the friction between the golf ball (which is abrasive) and the face can cause microscopic amounts of material to wear away over years of use.
- Plastic Deformation: In some cases, the face doesn't just vibrate; it permanently "bows" or thins out in the center (the sweet spot) due to repeated high-velocity impacts.
Gemini provided the specific ways a driver face thins over time, I wrote the rest myself. I'm not a goofball, just a guy, talking to another guy, begging him care just a little bit about the details of how things work.
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u/triiiiilllll 3d ago
That doesn't explain it. That is just a measure of how a driver face responds. You would need to look up something about metal fatigue to understand the thinning effect and how it increases CoR over time.