Physics heads, Yonex sweetspots as measured by TW university....

Help me learn about physics and or learn about TW University measurements.

So, the Percept 97, Vcore 98, and Ezone 98 and 100 have the same sweetspot as does the Vcore 95. (so why not just use the more maneuverable 95, same sweetspot?).

Anyway, the Percept D has a slightly larger sweespot, the H even higher than all of these.

Vcore 100 and Percept D have the same as well.

Say what?
 

Tranqville

Professional
Honestly, i don't pay much attention to that data. It shows my Head Prestige Tour '21 as having same sweetspot as Pure Strike Tour G3, while I absolutely know, based on extensive hitting with both racquets in different string setups, that PT's sweetspot is small and PST's huge.
 

Grafil Injection

Hall of Fame
80% of rackets have TWU sweet-zones between 14sqi and 17sqi, highly correlated to swing-weight. If those extra 3sqi were around the outside of a sweet-zone circle, the larger one would be 5.6mm bigger radius. That's about half the gap between two typical strings. Can you select which string you hit when playing? No, neither can I. I should think the larger sweet-zones definitions around 30-40sqi are the ones to compare.
 
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80% of rackets have TWU sweet-zones between 13sqi and 16sqi, highly correlated to head-size. If those extra 3sqi were around the outside of a sweet-zone circle, the larger one would be 5.6mm bigger radius. That's about half the gap between two typical strings. Can you select which string you hit when playing? No, neither can I. I should think the larger sweet-zones definitions around 30-40sqi are the ones to compare.
Probably I am not understanding but I can select string. The 30-40 ones to compare, how does that fit into the Yonex ones I am discussing above? Are any Yonex that category or is that something different?
 

Grafil Injection

Hall of Fame
Probably I am not understanding but I can select string. The 30-40 ones to compare, how does that fit into the Yonex ones I am discussing above? Are any Yonex that category or is that something different?

The Yonexes you mentioned have sweet-zones that are very similar to each other around 16-17sqi. In itself those measures are completely irrelevant because no one can notice a 3sqi larger sweet-zone, let alone a 1sqi one. However, they are likely to be indicative of a larger effective hitting area for the ones at the upper end of the range. The effective hitting areas of rackets are in the 30-40sqi size.

The main drivers to sweet-zone size as defined by TWU are likely to be head-size, swing-weight and racket stiffness. They define it as the area that returns more than 30% of energy, which generally larger, stiffer and heavier (i.e. more powerful) rackets will do. So the Percept 97H likely achieves a high sweet-zone size because of its weight mostly. If you want a really larger sweet-zone, get a stiff 100sqi racket and weight it up to 330g+ unstrung, a la Murray.
 
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The Yonexes you mentioned have sweet-zones that are very similar to each other around 16-17sqi. In itself those measures are completely irrelevant because no one can notice a 3sqi larger sweet-zone, let alone a 1sqi one. However, they are likely to be indicative of a larger effective hitting area for the ones at the upper end of the range. The effective hitting areas of rackets are in the 30-40sqi size.

The main drivers to sweet-zone size as defined by TWU are likely to be head-size, weight and racket stiffness. They define it as the area that returns more than 30% of energy, which generally larger, stiffer and heavier (i.e. more powerful) rackets will do. So the Percept 97H likely achieves a high sweet-zone size because of its weight mostly. If you want a really larger sweet-zone, get a stiff 100sqi racket and weight it up to 330g+ unstrung, a la Murray.
Aha, yeah, I don't need a large sweeetspot, was just curious about the measurements, the return of energy measurement makes sense, therefore the H and D being higher, the Regna is stiffer too so that explains that one.

The VC 95 has the same spot as the Ezone 100 , must be stiffness sw
 

Grafil Injection

Hall of Fame
Aha, yeah, I don't need a large sweeetspot, was just curious about the measurements, the return of energy measurement makes sense, therefore the H and D being higher, the Regna is stiffer too so that explains that one.

The VC 95 has the same spot as the Ezone 100 , must be stiffness sw

Yes, sw/weight i.e. polarisation is probably driving the Vcore 95 figure. That racket is what I would call naturally polarised because of its very teardrop shape.
 

Grafil Injection

Hall of Fame
TWU sweet-zone (power-zone) is highly correlated to SW, like many things. Note that, as mentioned above, this is a relatively small area near the centre of the racket-head, and there is very little difference between rackets. I.e. it is about how big is the area where you can hit a very good shot. It's not about whether a racket is forgiving by having a larger, what I call, hitting-zone, although there is likely to be good correlation with that too.

Sweet-zone-Swing-weight-correlation.jpg
 
TWU sweet-zone (power-zone) is highly correlated to SW, like many things. Note that, as mentioned above, this is a relatively small area near the centre of the racket-head, and there is very little difference between rackets. I.e. it is about how big is the area where you can hit a very good shot. It's not about whether a racket is forgiving by having a larger, what I call, hitting-zone, although there is likely to be good correlation with that too.

Sweet-zone-Swing-weight-correlation.jpg
I had this thought before looking randomly at all these (someone was wondering about the PA98 sweetspot so I looked it up compared to Ezone), the thought was a 100 to be more forgiving would need to foresee a ton of shots being in the extra "forgiveness" zone above and beyond a 98, and that extra part is smaller than a fingernail spread out across the upper hoop. That won't happen often at all.

Now seeing the spot in graphic form solidifies that thought.

Power and launch angle in defense can create forgiveness, but really the "extra" sweetsot isn't useful that often.
 
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Hawks9451

Professional
TWU measurements are authentic to whatever formula they're using, but the conclusions are basically meaningless. Even normalizing for spec variations, the idea that you can conclusively measure the area of a racket's "sweet spot" is ridiculous.

It's a maze for the "enthusiast" consumer to get lost in.
 
TWU measurements are authentic to whatever formula they're using, but the conclusions are basically meaningless. Even normalizing for spec variations, the idea that you can conclusively measure the area of a racket's "sweet spot" is ridiculous.

It's a maze for the "enthusiast" consumer to get lost in.
isn't it useful as a comparison tool though since they are using the same string , tension, impact force etc.? Like it might not be 100% accurate but it's equally "inaccurate" to the same degree for each racket they post results for so there is some value in the comparison? Or no?
 

Hawks9451

Professional
isn't it useful as a comparison tool though since they are using the same string , tension, impact force etc.? Like it might not be 100% accurate but it's equally "inaccurate" to the same degree for each racket they post results for so there is some value in the comparison? Or no?
You may as well compare the way different rackets taste.

Anything can be isolated for a delta.
 
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