Rubber properties understanding

@spinner24

Congratz, you've found out that no-spin variation is good.

Now go and learn how to make your heavy backspin look like no-spin, and your no-spin look like heavy backspin. No rubber change required!

Okay. I will add a few things.

Gears first. Perhaps this was explained, but I think it could be explained better.

The image refers to the gears of a car. It is a metaphor. First gear is slow for instances where you need not to accelerate too fast like going up a hill slowly or going down a hill slowly. Then the faster gears for a car are for steady driving at a faster speed like on an open highway. The middle gears are for moderate speeds, not slow or fast. It is like that. If you have ever driven a standard (stick shift) instead of an automatic, gears make more sense.

There is some equipment that is very fast and it is hard to play slow shots with. Where you have to have very good touch to play slow shots because the blade, or rubber, causes the ball to catapult at the slightest touch. And either the blade or the rubbers can fall into that category of high gears only.

There are some pieces of equipment that are slow, slow slow and to get the ball moving faster you have to work EXTREMELY hard. So touch shots are easy, short shots, taking the ball over the table, getting a high angle off to the side from close to the table. But then power shots from further away become increasingly harder to make shots that are fast enough.

Those are examples of equipment with not so many gears. Again, it could be the rubbers or the blade that is stuck in one gear. But ultimately you can take a slow blade and put fast rubbers on it and get a few extra gears, or you can take a fast blade and put slow rubbers on it and get a few extra gears. So there are ways of getting a setup to work for you.

A rubber or blade with many gears would be one where, on touch shots and soft play, the equipment plays slow and on power shots the top end on the equipment is, nevertheless, quite fast. This is why the top Chinese players use DHS H3. It is very controllable and easy to play short game and touch shots. And then when you take big shots it plays with great power because, with the harder sponge and the TACKY topsheet, when you don't put much effort in, it plays like it is slow, but when you swing hard, the compression and rebound of the sponge gets activated and gives you the extra gears at the higher end. However, you have to have really good impact and precise contact, you have to have very good technique to get this from an H3 rubber. Whereas a rubber like Tenergy is much easier to use for someone who is not that level because Tenergy does so much of the work for you even though it has FEWER gears.

An easy example of a blade with extra gears, most of the InnerForce type blades where the carbon is next to the core instead of being next to the top ply, they play slow almost like an all wood blade on lower intensity shots. And then when the swing is bigger, the deeper contact causes you to reach the composite ply and get the extra speed and power from the composite ply.

Does that make sense?

I am sure this is explained in the articles romanzdk posted from "Thoughts on Table Tennis". That is a great resource. But hopefully these are simple explanations that make the terms a bit easier to understand.

Tackiness: to understand the term "Tacky", there is another term that needs to be present. It is hard to talk about tackiness without comparing it to the kinds of rubber that have a "grippy non-tacky" topsheet.

Lets use some classic rubbers to look at this. Sriver is grippy non-tacky. If you touched the Sriver topsheet with your finger it would feel smooth and not sticky. But, if you applied a little pressure, it would feel grippy, WITHOUT feeling sticky. If you left a Sriver rubber exposed to the air over night, it would not end up being covered with dust particles that are hard to remove. If you pressed a ball into the Sriver rubber and turned the racket upside down, the ball would fall just as you would expect it to. If you put a sheet of plastic that is a regular film of plastic with no stickiness on either side, the sheet of plastic will not stick to the topsheet.

With a tacky rubber like the old versions of H3 or many versions of 729, Globe or Haifu Whale, when your finger touched the topsheet, the topsheet would feel sticky. Not like the grippy non-tacky rubber at all but sticky like when there is old glue dried on something and you touch it and it sticks to your hand. When you leave that rubber out over night without a covering, there will be a layer of dust and dirt that stuck to the rubber which will be hard to clean off. You will need water and your hand or a sponge or cloth to clean it off. With a tacky rubber, if you press a ball to the rubber and try to pick the ball up with the racket facing down, YOU CAN sometimes pick the ball up, and it will stay on the topsheet, defying gravity for some time before falling off. When you put a regular plastic film on a tacky rubber, it will stick because of how sticky the topsheet is.

Here, watch the video.


As far as how grippy non-tacky rubber performs in comparison to tacky rubber, there are soooooo many details. But both kinds of rubbers have their advantages and disadvantages. Grippy non-tacky rubber relies on the topsheet grabbing the ball, the ball sinking into the sponge, and then the sponge rebounding and projecting the ball out, thereby creating, from the rebound, what gets called mechanical spin. A tacky rubber does not do this quite the same way because it is sticky.

To spin the ball with a tacky rubber though, what you do is brush more and let the stickiness grab the ball while having thin or deep contact and very fast racket speed. Deep contact for the more powerful strokes. Thinner contact for the slower more spinny strokes. But the point is, in grippy non-tacky rubbers, you use the sponge more with the grip of the topsheet. And in tacky rubbers you use the topsheet more and you need to be very powerful to utilize the harder sponge with the topsheet.

It is worth understanding that there are advantages and disadvantages to either kind of rubber. Some of the advantages of the tacky rubber are MANY MORE GEARS. A simple advantage of grippy non-tacky rubbers is that the catapult and the mechanical spin make it so you can take small strokes and make powerful shots. The forgiveness of the grippy non-tacky rubbers gives you more room for error on certain shots.

However, you can see, in the top 20 in the world many players using either kind of rubber. So, they both can give you what you need if you develop your technique with one of them.

Throw angle. Again, I am sure the Thoughts on Table Tennis sight gives great info on this. I am just going to give a small piece of info.

A certain amount of what throw angle is, has to do with the ration between these two factors:

1) Spin
2) Speed

The ration can be expressed like this:

Spin/Speed Ratio = meaning that there is a higher degree of spin in relationship to speed. An example would be T05.

Speed/Spin Ratio = meaning that there is a higher degree of speed in relationship to spin. An example would be Calibra.

When the ratio between spin and speed is such that there is more spin than speed:

1) You will usually get more arc on your shots.
2) It is easier to use the spin to arc a higher ball onto the table.
3) The rubber grabs more in relationship to its catapult so the ball would usually jump off a little higher on a topspin brush stroke.
4) Sometimes a rubber with a high Spin/Speed Ratio is more reactive to incoming spin. Therefore, it can take more touch and higher level technique to utilize the properties of the higher Spin/Speed Ratio. In other words this kind of rubber is usually a poor choice for a beginner.

When a rubber exhibits this high Spin/Speed Ratio, it is often called A HIGH THROW rubber.

When the ratio between speed and spin is such that there is more speed than spin:

1) The spin will effect the arc less because there is more speed than spin so the arc will be flatter.
2) It is harder to use spin to arc the ball onto the table.
3) The rubber catapults the ball more and grabs and therefore spins the ball less so the ball comes off the rubber lower on a topspin shot. This also means you can brush less and make deeper contact more safely.
4) Sometimes a rubber with a high Speed/Spin Ratio is less reactive to incoming spin. This is also not exactly what a newer player wants because of the added speed. But for a higher level player this can sometimes make it easier to control on return of serves and counterlooping.

When a rubber exhibits this high Speed/Spin Ratio, it is often considered low throw. Giving credit where credit is due, PNut did give some of this information. But one of the things that made it hard to listen to the quintessential Physics/Engineer/TT Expert was how fond he was of calling everyone an idiot.

For a beginner/intermediate player, a middle of the road rubber that can do everything well so you can develop all your strokes would be preferable rather than a rubber that was heavy on the Spin/Speed side of things or a rubber that was heavy on the Speed/Spin side of things.

There are drawbacks and advantages to any piece of equipment whether low or high throw, or anywhere in between.

Dwell time:


Most of dwell time is really in the touch, feeling and deftness in the person's hand.

In the "Backspin Catcher" exercise, notice how Freitas makes the dwell time so short that he can keep the ball contacting the rubber in the same spot over and over again while continuing to spin despite how grippy his rubber is.

In the "Grabbing and Punching" exercise, notice how the ball is caught on the rubber without rebound.

Really, dwell time is the ability of the person to hold the ball on the blade face for just a little longer while spinning the ball which allows the rubber and sponge to distort more and rebound more so you end up with more spin.

But certain softer blades make it easier to begin learning that kind of control of which Freitas shows to an extreme degree.

And a blades ability to help you with that skill is often referred to as dwell time.


Sent from The Subterranean Workshop by Telepathy