Grass Dtec Spin Reversal: See the Actual Effect in Slow-Motion Video

[palguay]

Tibhar Grass Dtec amount of spin reversal and speed reduction

 

[brokenball]

I didn't hear if the Grass DTec was 0X or had sponge. That makes a big difference. Assuming 0X for now.

Olivier Mader AKA Pushblocker used Grass Dtecs 0X long ago but the ITTF made Grass Dtects change a bit and "ruined" it for Pushblocker. Pushblocker switched to Giant Dragon Talon 0X which is what I had been using.

I am surprised at how much grip the current Grass DTecs has. You can see that when impacting the paddle with top spin that the rotation of the ball drops slows a lot. This is because the friction causes the ball to bounce up at a higher angle than what should normally occur if Grass DTecs was truly frictionless. Basically the rotational energy gets converted into potential energy due to the increased elevation of the ball after impact. Assuming the numbers are right one can calculate the energy before and after impact. The amount of energy lost is significant

The same happens in reverse when the ball makes contact with back spin. I did not expect the ball to grip and shoot downwards so much. When I play with my Giant Dragon Talon 0X I can block balls back without the ball dropping into the table or net. This allows me to use the incoming back spin as my top spin so I can hit a little more aggressively.

The fact that the ball seems to grip the Grass Dtec makes me wonder if there is a sponge. Even my chopping paddle with TSP P-1R 1.4mm doesn't seem to have that much grip.

Palguay. It would be nice if you kept the time base consistent. Use meters per second and revolutions per second. It is easier to visualize.

 

[palguay]

I didn't hear if the Grass DTec was 0X or had sponge. That makes a big difference. Assuming 0X for now.

Olivier Mader AKA Pushblocker used Grass Dtecs 0X long ago but the ITTF made Grass Dtects change a bit and "ruined" it for Pushblocker. Pushblocker switched to Giant Dragon Talon 0X which is what I had been using.

I am surprised at how much grip the current Grass DTecs has. You can see that when impacting the paddle with top spin that the rotation of the ball drops slows a lot. This is because the friction causes the ball to bounce up at a higher angle than what should normally occur if Grass DTecs was truly frictionless. Basically the rotational energy gets converted into potential energy due to the increased elevation of the ball after impact. Assuming the numbers are right one can calculate the energy before and after impact. The amount of energy lost is significant

The same happens in reverse when the ball makes contact with back spin. I did not expect the ball to grip and shoot downwards so much. When I play with my Giant Dragon Talon 0X I can block balls back without the ball dropping into the table or net. This allows me to use the incoming back spin as my top spin so I can hit a little more aggressively.

The fact that the ball seems to grip the Grass Dtec makes me wonder if there is a sponge. Even my chopping paddle with TSP P-1R 1.4mm doesn't seem to have that much grip.

Palguay. It would be nice if you kept the time base consistent. Use meters per second and revolutions per second. It is easier to visualize.

Thanks for your feedback, It is OX and no sponge. In terms of conversion we used the earlier template as everything was ready and to change anything means I have to spend some time on it and I was held up with other things so will keep it in mind for future video's

 

[palguay]

Forgot to mention the ply used is Zhang Jike Super ZLC

 

[igorponger]

THE FACT UNDENIABLE -- LONG PIPS all using a grippy rubber materials.
Nice practical experiment, indeed. This is the most convincing video to sustain the fact that long pips all do have a decent amount of grippiness. That's to say :
- You can't get enough spin reversal unless you commit a "violent action" with your rubber. (some illegal treatments).
Again, "spin reversal" is just a pipe dream, and more so with all the long pips as currently listed into the LARC..
And, yes, the "dead balls" still practicable.

 

[blahness]

Having a spin loss of only 50% is actually really respectable given the larger ball and the effect of air resistance and also collision with the table. Furthermore, this is with a stationary bat, if the player moves the bat in a skilled manner he can add to this energy (not sure if it can even exceed 100% with this added energy).

 

[igorponger]

SPIN REVERSAL is A COMMON MISBELIEF.

Spinlord Dornenglanz is another popular pips with twiddling players. Contrary to popular belief, this one does have grippiness a lot, far over CoF 0.5, -- no spin reversal at all, and a lot of dead balls instead. It is the presence of grippiness on the pips that enables Sweden Gustaf Eriksson to attack violently.

 

[DukeGaGa]

I applaud you on providing concrete methods of measurements.
And that is a great start.
And I see why you chose Grass DTec (probably because Manika Batra & now 500 million Indian women are using Grass Dtec LOL)

However such a study though gives some perspective, will be more useful if you do a comparison between
DTec & Magic 77 (functionally useful) or between Dtec & Jahanam Rawottex or at least between Dtec & Feint Long 3 or between Dtec & Feint Long Classic or between Dtec & Victas Curl P1r like you did for fastArc & Dignics in another video.

Another issue is measurement of spin loss. This gives a false impression that long pips actually causes "spin removal" and not provide any positive "spin reversal" because you are showing me only negative "spin reversal"

Because this is not really what happens in the case of a chop ,where the contact angle is close to 0 degrees (in a horizontal chop) & maybe 45 degrees is a vertical chop, As compared to almost 90 degrees contact angle during a block when a blocker like Manika Batra uses it (practically around 70 degrees).
Also there is the issue of racket acceleration to reverse the spin and dwell time for spin amplification etc.

So real measurement would be something like a chop coming out of Chen Weixing's hand with him using a true high aspect ratio long pips against Ma Long's boosted loop
(I used Chen Weixing because he seems to be the most technically perfect backhand chopper & though Joo Sehyuk is the true GOAT of all of tabletennis & what separates him from the rest is his forehand chop, he is more of an instinctive & natural chopper than a technical chopper and I have seen Chen Weixing in action many times).

I know. All this is asking for too much with so many variables involved. But just saying

All this talk about spin reversal… but actually it’s maintaining the spin, it’s the direction of travel that’s been reversed giving you the illusion that the spin reversed. So there is no “false impression” that long pips remove the spin, because as long as the surface isn’t perfectly smooth, a spinning object touching that surface will lose some of its rotational momentum. Chopping is different, it adds spin to the ball because the paddle is moving in the same direction of the spin, it’s the same principle with an old school whipping top. Also, most good choppers don’t use long pips nowadays, short pips give more control to the spin, and is better for counter attacks. Long pips are used more as a close table defenseive play, like Zhou Xintong, or attacking play like He Zhujia, Deng Yaping.

Btw you spelled the name wrong, it’s Joo Sae-hyuk, not Joo Sehyuk. And no, he is not the GOAT of all table tennis, he would have gotten a lot more championships titles if he is. However he is considered by a lot of people to be the best ever chopper.