A Big Bounce ?

[cyberheater]

Just had a big bounce on the Davis vs Dale match and that is a brand new cloth with barely any playing time. The white has also been cleaned regularly.

I really don't think it's anything to do with chalk.

[cueman]

Just had a big bounce on the Davis vs Dale match and that is a brand new cloth with barely any playing time. The white has also been cleaned regularly.

I really don't think it's anything to do with chalk.

I don't to be honest. I think heat is the biggest factor because whenever you warm rubber it expands and that is going to create a more bouncy reaction. We never had big bounces prior to the table heaters being on, and since they moved to these thermostatic controlled heaters I think it has compounded the problem.

I've played on tables with table heaters and they certainly do bounce a lot more than one without, though the cloth is also very lively and any spin on the cueball is exagerated compared to a table without the heaters.

[luke-h]

I don't to be honest. I think heat is the biggest factor because whenever you warm rubber it expands and that is going to create a more bouncy reaction. We never had big bounces prior to the table heaters being on, and since they moved to these thermostatic controlled heaters I think it has compounded the problem.

I've played on tables with table heaters and they certainly do bounce a lot more than one without, though the cloth is also very lively and any spin on the cueball is exagerated compared to a table without the heaters.

Also another thing to note, can anyone answer if there were issues with "big bounces" prior to steel backed cushions?

[Catch 22]

Also another thing to note, can anyone answer if there were issues with "big bounces" prior to steel backed cushions?

I was thinking this too .

I've never played on a star table ( don't think I ever will either ) . But I was told they are actually pretty rubbish table , very cheaply made ....is this true ?

[cyberheater]

I don't to be honest. I think heat is the biggest factor because whenever you warm rubber it expands and that is going to create a more bouncy reaction. We never had big bounces prior to the table heaters being on, and since they moved to these thermostatic controlled heaters I think it has compounded the problem.

I've played on tables with table heaters and they certainly do bounce a lot more than one without, though the cloth is also very lively and any spin on the cueball is exagerated compared to a table without the heaters.

I was thinking this too .

I've never played on a star table ( don't think I ever will either ) . But I was told they are actually pretty rubbish table , very cheaply made ....is this true ?

I can't remember it happening before they started to use Star Tables. Geoff the table fitter on here doesn't think they are as good as the british made tables.

[Geoff Large]

I have my own theory about Big Bounces

the ball bounces off the cushion rubber on the underside edge only , not the flat side , if rubber is straight on the block of wood then all the cushion rubber is set at the correct height .
Now has anyone looked down the cushion to see if the wood is straight to start with , is the rubber put on with a slight dip or hump , then at that point the ball is not rebounding as it would with uniformed height .
go down the club and look down the length of a cushion on various tables , you may be in for a shock as some are as wavy as a corrugated roof .
I am taking a stab in the dark at this , but my guess is the point of the BIG BOUNCE may just be at that point of impact the rubber is slightly lower than the rest of the cushion , it may be the rubber is low on the block or that the block is bowed or has a divot in before the rubber was put on level with the top edge .
I have also seen some rubber that is not finished as good as other sets , a fault in the moulding process ?
another scenario , a air bubble in the rubber was formed , now you may have seen old Burroughs and watts Vacuum steel cushions , this was a air pocket behind the rubber to make the rubber bounce better , what if a bubble is inside the rubber at that point of impact and when squeezed by the impact flirts back more than solid rubber ?

another scenario , a bit of dust or muck just on the cloth that the ball hits just before impact lifting the ball slightly enough for the underside of the cushion to make the contact slightly lower on the ball and therefore give more bounce .
I have witnessed badly made blocks that are too high that make a ball dead when the ball hits , and other blocks that low that the ball kicks upwards and ball jumps on impact , this is proof that a ball will have a better rebound bounce if you can get the rubber edge at the lowest facing edge to hit he ball just a fraction above middle or centre line of ball , not too low or the ball will bounce upwards off the rubber face , which brings me back to a low spot on the rubber or a bit of dirt lifting the centre of the ball up before impact as the culprit of the BIG BOUNCE.

thats my theory anyway

and steel blocks have been about since Queen Victoria so i don't think you can blame them .

As for the quality of star tables , I would like to see one when it has been recovered say 50 times and over 100 years of use if they last that long , why spray gold paint over good wood , thats all I'm saying

[cantpotforshíte]

The only way that a ball can come off the cushion faster than it went on to it, without violating the most inviolable laws in physics; ie. the first law of thermodynamics namely the law of conservation of energy, is if energy is already stored in the cushions by the table fitter.
Many people will say that is impossible for a ball to come off the cushion faster than it went on to it without violating those laws, but people tend to forget that the law of conservation of energy applies only to closed systems, and closed systems don't actually occur in our universe (apart from on physics and engineering exam papers). A snooker table (especially a newly fitted one) isn't a closed system just as a loaded crossbow isn't a closed system; it already has energy stored in it.
Hopefully Geoff can help me here as I am pretty clueless as to the actual process by which the cushions are fixed. As far as I know the cloth is wrapped around the cushion, then pulled quite tight, and fixed underneath (with staples?) so that the rubber cushion is actually very slightly (or even imperceptibly) compressed, like a spring. That there is stored energy, which is trying to release itself at all times.
If the cueball were to hit the cushion and somehow make it easier for the cushion to decompress a little (a thousandth of an inch could be enough), the energy released could be enough to make the ball come off the cushion faster than it went on to it, without violating the laws of physics. The extra energy simply comes originally from the table fitter's arm, and the bacon butty that he has for breakfast, which ultimately gets it's energy from the Sun.
I don't know enough about cushion assemblies to even guess about the 'somehow', I'll leave that to those that do know.
But this would only be likely to happen on a newly fitted table, as they have at tournaments, and maybe superfast slippy cloths would make it more possible, if the friction between the cushion assembly and the table bed has anything to do with holding it all together.
But as far as the laws of physics go, that is the only way that a ball can come off the cushion faster than it goes on to it; stored energy being released.
Whether or not balls DO occasionally come off the cushions faster than they went on, I don't know, but I do know that professional snooker players have very good perception.

[luke-h]

The only way that a ball can come off the cushion faster than it went on to it, without violating the most inviolable laws in physics; ie. the first law of thermodynamics namely the law of conservation of energy, is if energy is already stored in the cushions by the table fitter.
Many people will say that is impossible for a ball to come off the cushion faster than it went on to it without violating those laws, but people tend to forget that the law of conservation of energy applies only to closed systems, and closed systems don't actually occur in our universe (apart from on physics and engineering exam papers). A snooker table (especially a newly fitted one) isn't a closed system just as a loaded crossbow isn't a closed system; it already has energy stored in it.
Hopefully Geoff can help me here as I am pretty clueless as to the actual process by which the cushions are fixed. As far as I know the cloth is wrapped around the cushion, then pulled quite tight, and fixed underneath (with staples?) so that the rubber cushion is actually very slightly (or even imperceptibly) compressed, like a spring. That there is stored energy, which is trying to release itself at all times.
If the cueball were to hit the cushion and somehow make it easier for the cushion to decompress a little (a thousandth of an inch could be enough), the energy released could be enough to make the ball come off the cushion faster than it went on to it, without violating the laws of physics. The extra energy simply comes originally from the table fitter's arm, and the bacon butty that he has for breakfast, which ultimately gets it's energy from the Sun.
I don't know enough about cushion assemblies to even guess about the 'somehow', I'll leave that to those that do know.
But this would only be likely to happen on a newly fitted table, as they have at tournaments, and maybe superfast slippy cloths would make it more possible, if the friction between the cushion assembly and the table bed has anything to do with holding it all together.
But as far as the laws of physics go, that is the only way that a ball can come off the cushion faster than it goes on to it; stored energy being released.
Whether or not balls DO occasionally come off the cushions faster than they went on, I don't know, but I do know that professional snooker players have very good perception.

Good point as they only tack the cloth of the cushion they could compress some of the rubber, I would be interested to know if the exact places that the big bounce occurs is there a tack directly behind where the "big bounce" takes place, slipping of cloth or the outer most part of the minimal indentation being slightly more compressed???

[moglet]

These theories are all fine except they miss the underlying condition that these big bounces aren't normally repeatable on the same spot on the cushion all other things being equal.

The "stored energy" theory would necessarily be repeatable.

If it were variation in cushion height alone the bounce would always be bigger if the cushion were too low at a specific point.

If there was a small deposit of chalk on a certain point on the cushion the bigger bounce would be repeatable if the chalk spot can be found, or indeed a chalk spot on the ball though this is difficult to set up to repeat the effect. This has already been identified as one cause.

Slightly higher temperatures would, if at all, affect all the cushion not just a particular spot.

It is likely the faster cloths used today, assisted by heating, exaggerate this effect.

It is the random occurrence of the apparently unrepeatable bigger bounces that is difficult to resolve unless you understand the nature of the ball surface. There is a definite correlation between unexplained ball to ball kicks and bigger cushion bounces.

[cyberheater]

I don't believe for one second that there has ever been an instance where the white has come off a cushion faster then it went on unless a significant amount of spin was put on the white first.

[andy carson]

It is the random occurrence of the apparently unrepeatable bigger bounces that is difficult to resolve unless you understand the nature of the ball surface. There is a definite correlation between unexplained ball to ball kicks and bigger cushion bounces.

i remember a bit on Qi once where they stated that if a cue ball was scaled up to the size of the earth, there would be mountains bigger than everest and canyons even deeper than that height all over the ball

[cyberheater]

i remember a bit on Qi once where they stated that if a cue ball was scaled up to the size of the earth, there would be mountains bigger than everest and canyons even deeper than that height all over the ball

And I bet that's on a brand new cue ball. The cue balls we've got at our club looks like they've been in a accident. Strangely though, hardly any kicks. Maybe they are too rough for kicks because the other ball doesn't have a chance to lock on to it.

[andy carson]

And I bet that's on a brand new cue ball. The cue balls we've got at our club looks like they've been in a accident. Strangely though, hardly any kicks. Maybe they are too rough for kicks because the other ball doesn't have a chance to lock on to it.

yep brand new ball!

i find it stranger that kicks and "big bounces" have come into the game a hell of a lot with the new ball material, layered tips with bits of glue all over them along with the superfine cloth they use on the pro circuit....

the thicker cloth as used in most clubs you get a hell of a lot less kicks & big bounces etc, plus 99% of club players will generally use elks or blue diamond and the tables are not heated (unless its summer )

[cantpotforshíte]

I don't believe for one second that there has ever been an instance where the white has come off a cushion faster then it went on unless a significant amount of spin was put on the white first.

Aye, I meant to say that the only way a rolling ball with no spin on it could come off the cushion faster than it went on would be if there was energy stored in the cushions by the table fitter.
Whether this has actually ever happened or not, I don't know.

[cantpotforshíte]

These theories are all fine except they miss the underlying condition that these big bounces aren't normally repeatable on the same spot on the cushion all other things being equal.

The "stored energy" theory would necessarily be repeatable.

Once the energy is dissipated, ie. when the cushions have sprung from their compressed state, it wouldn't be repeatable. It could only happen so many times on a newly fitted table.