Heavier cue for breaking?

[Jedi V Man]

My buddy has a 21 ounce Bunjee break cue with the phelonic tip/ferrull on it.

We drilled out the butt and poured in 6 ounces of melted lead in it.

On my 9' table you can break a 8 ball rck, set down the cue, go get a beer, come back and the balls are still moving on the table. I've never broke with anything like it in my life.

Feels like you mounted the cue on the front of a suburban and drove down the table to break, like a battering ram....

If you make less than 3 balls with it you screwed up somehow.

 

[Chris]

Yes, I understand that your hand and arm is also part of the acceleration equation as well, and I guess I'm over-simplifying things by totally dropping it from the acceleration equation.

But I think we're both over-simplying this (Chris, this applies to you as well). I think there is more much more going on, both physics-wise and body mechanics-wise, than what we're taking into account. I don't think it's as simple as momentum = mass1*velocity1 = mass2*velocity2, where the amount of total momentum is exactly the same for both cases. I actually think the amount of total momentum your body can put out does change depending on the weight of the cue.

If you've ever played organized baseball, you'd agree that the weight of your bat does indeed matter a lot (just assume that we're using only wooden bats). I can definitely hit the ball further with a 27oz bat than I can with a 32oz bat. Based on your simplification, I should be able to hit the ball the same distance regardless of bat weight, but my data shows otherwise. The increase in my bat speed clearly outweighs the effects of the decrease in total mass. To go to an extreme, try hitting a ball with a 27oz bat, and then try hitting a ball with a 54oz bat (place the ball on a T, such that timing isn't a factor). I guarantee you that you'll hit the ball much further with the 27oz bat.

So the moral to my story is that there is much more going on than what we're accounting for. I believe there is a certain optimal cue weight (or bat weight) that makes our body exert the maximum amount of energy. For me in baseball, that sweet spot is a 27oz bat. For breaking in pool, I believe the sweet spot for most players lie in the lighter than average end of the weight spectrum for cues (probably around 16-18oz).

The problem lies in the fact we are talking about momentum, which won't increase with a larger or smaller cue due to the accompanying decrease or increase in velocity. However, the ENERGY transferred to the cue ball will increase with the faster stroke associated with the lighter cue. (Kinetic Energy = 1/2 * M * V^2) Since KE varies with the square of the velocity, doubling the velocity will result in quadrupling the Kinetic Energy, whil doubling the mass will only double the Kinetic Energy.

 

[Chris]

MASS X SPEED = ENERGY transfered to the cueball thus the rack.

Not exactly. Momentum equals mass X velocity. Energy equals 1/2 X Mass X the square of the velocity.

Momentum is the derivative of Energy with respect to Position.

 

[Andrew Manning]

The problem lies in the fact we are talking about momentum, which won't increase with a larger or smaller cue due to the accompanying decrease or increase in velocity. However, the ENERGY transferred to the cue ball will increase with the faster stroke associated with the lighter cue. (Kinetic Energy = 1/2 * M * V^2) Since KE varies with the square of the velocity, doubling the velocity will result in quadrupling the Kinetic Energy, whil doubling the mass will only double the Kinetic Energy.

I've seen the kinetic energy formula used in this debate before, and it's very misleading. Yes, a light/fast cue has more kinetic energy than a heavy/slow cue with equal momentum. But kinetic energy of the cue is irrelevant in this discussion. Kinetic energy DOES NOT move the cue ball. Transfer of momentum moves the cueball. Kinetic energy is conserved only in elastic collisions, and the stick/ball collision is ny no means elastic. Momentum, however, is conserved in all collisions.

If you shot an arrow (with a cue tip on it) out of a crossbow at a cue ball, it would have orders of magnitude more kinetic energy than a 19 oz. break cue, no matter who's stroking the cue. But I'd wager the cue ball wouldn't go any faster than a medium stroke with a playing cue, and possibly mot even that fast. Kinetic energy is not the relevant quantity. Momentum is.

-Andrew

 

[Chris]

I've seen the kinetic energy formula used in this debate before, and it's very misleading. Yes, a light/fast cue has more kinetic energy than a heavy/slow cue with equal momentum. But kinetic energy of the cue is irrelevant in this discussion. Kinetic energy DOES NOT move the cue ball. Transfer of momentum moves the cueball. Kinetic energy is conserved only in elastic collisions, and the stick/ball collision is ny no means elastic. Momentum, however, is conserved in all collisions.

If you shot an arrow (with a cue tip on it) out of a crossbow at a cue ball, it would have orders of magnitude more kinetic energy than a 19 oz. break cue, no matter who's stroking the cue. But I'd wager the cue ball wouldn't go any faster than a medium stroke with a playing cue, and possibly mot even that fast. Kinetic energy is not the relevant quantity. Momentum is.

-Andrew

The cue tip / CB collision is mostly elastic, and can be modeled as such for the purposes of this discussion. Very little energy is lost to sound, heat, etc, so the vast majority of it is transferred to the CB.

 

[Andrew Manning]

The cue tip / CB collision is mostly elastic, and can be modeled as such for the purposes of this discussion. Very little energy is lost to sound, heat, etc, so the vast majority of it is transferred to the CB.

I don't want to sound antagonistic, since this has been and I hope will continue to be a polite debate, but I don't believe this to be true. I believe deformation of the leather in the tip, as well as sound, heat, etc. dissipates a significant quantity of the energy on contact.

Drop a leather tip on a hard smooth surface, and see how high it bounces. It loses well over half its kinetic energy during the collision, which is clearly visible by the fact that it bounces less than half the height from which it was dropped. For more convincing results, drop your cue (wouldn't recommend using the Balabushka) tip pointed straight down on the floor (uncarpeted for best results), and it won't bounce very high either; I'm guessing less than half of its original height. Kinetic energy is not nearly conserved during impact with the floor.

I think kinetic energy is a misleading equation to reference in the break cue mass debate.

-Andrew

 

[bruin70]

According to Robert Byrne,,,,,,,,When you also consider the importance of precision and control, which are easier to achieve with a light cue,..."

why is this?????? most players lose control of the cb by breaking TOO HARD, which usually means breaking with speed, which has nothing to do with cue weight.

 

[Chris]

I don't want to sound antagonistic, since this has been and I hope will continue to be a polite debate, but I don't believe this to be true. I believe deformation of the leather in the tip, as well as sound, heat, etc. dissipates a significant quantity of the energy on contact.

Drop a leather tip on a hard smooth surface, and see how high it bounces. It loses well over half its kinetic energy during the collision, which is clearly visible by the fact that it bounces less than half the height from which it was dropped. For more convincing results, drop your cue (wouldn't recommend using the Balabushka) tip pointed straight down on the floor (uncarpeted for best results), and it won't bounce very high either; I'm guessing less than half of its original height. Kinetic energy is not nearly conserved during impact with the floor.

I think kinetic energy is a misleading equation to reference in the break cue mass debate.

-Andrew

You are correct. The collision is no where near perfectly elastic. However, it is nowhere near perfectly inelastic, either. So the extra speed from a lighter cue is somewhere between pretty important and not important at all.

Which means there are better ways to improve my break than using a lighter cue.

 

[Hal]

(Kinetic Energy = 1/2 * M * V^2) Since KE varies with the square of the velocity, doubling the velocity will result in quadrupling the Kinetic Energy, whil doubling the mass will only double the Kinetic Energy.

uh....yeah....

 

[X Breaker]

My break stick is roughly 1/2 oz. lighter than my playing cue... ~18.75 vs. 19.25 oz... which works well for me.

And my break stick is a Predator BK2, which I've had for about 1.5 months. I formerly broke with a BK1.

After trying out the BK2 for 2 weeks, I had my cuemaker shave off the phenolic tip and install a Talisman break tip in its place. We left the graphite wafer intact and super-glued the tip to the graphite, as instructed by Predator CS when I called them beforehand.

I found it VERY difficult to control whitey with the original phenolic tip.

It's much easier now.

Do you feel any difference between the BK1 with a leather tip and the BK 2 with a leather tip?

I am not asking you about the difference in features such as a laminated butt, with difference finish, with a more rear balance... but whether you can feel any actual difference when you break with it. Thanks in advanced.

I had a discussion with Neil about his breaking cue after he came to me and asked to try out the X Breaker in VF. Basically, I told him I agreed deflection is a factor, but it should not be a determining factor, and it certainly is not the major factor in achieving control on a breaking cue.

Unfortunately, all he wanted to talk about was "deflection." In my opinion, he has missed the point, may be that is why a breaking cue which was supposed to offer the best control with the lowest deflection is "hard to control" in its default state.

Anyway, going back to the weight. I know about the kinectic energy formula and I understand the agrument that speed is more important. I used to think a lighter cue was better until I started asking pro players to test the X Breaker. It surprised me how many professionals, especially the ones with a good break, prefer a heavy breaking cue.

Let me give you an example, Charlie Byrant now breaks with an almost 20 oz X breaker. Bustamente used an over 19.5 oz X Breaker in the WPC 2005. They both have a very hard break with good control, and they both have a lot of power eventhough their breakers are heavy.

Richard

 

[Cornerman]

The cue tip / CB collision is mostly elastic, and can be modeled as such for the purposes of this discussion. Very little energy is lost to sound, heat, etc, so the vast majority of it is transferred to the CB.

I think you're thinking of cueball to object ball collision. Tip to CB is another story.

Fred

 

[Cornerman]

Anyway, going back to the weight. I know about the kinectic energy formula and I understand the agrument that speed is more important. I used to think a lighter cue was better until I started asking pro players to test the X Breaker. It surprised me how many professionals, especially the ones with a good break, prefer a heavy breaking cue.

Let me give you an example, Charlie Byrant now breaks with an almost 20 oz X breaker. Bustamente used an over 19.5 oz X Breaker in the WPC 2005. They both have a very hard break with good control, and they both have a lot of power eventhough their breakers are heavy.

Richard

I think that when the trend to lighter break cues came about, amateur physicists decided to put a reasoning behind it. And the Kinetic Energy formula then reared its head, as it is now.

A detailed study on the "optimum break weight" (APAPP, Ron Shepard) has shown no bearing on the mass relation between one's shooting cue and break cues. None. The optimum break cue weight is determined by the muscles involved in the individual breaker's technique. That may result in a weight lighter or heavier than the individual's shooting cue weight my happenstance. It could be more or less than 19 oz.

Lighter vs. Heavier break weight is a complete red herring discussion.

Fred

 

[Chris]

I think you're thinking of cueball to object ball collision. Tip to CB is another story.

Fred

You are right. I tested it, and most energy is lost in the tip / CB collision. It is neither elastic nor inelastic, so the appropriate equation will be somewhere between the two. In other words, some of the extra energy is conserved, and some of it is not. So a lighter cue is better by a minimal amount, given the same energy going into the stroke.

 

[Chris]

I think that when the trend to lighter break cues came about, amateur physicists decided to put a reasoning behind it. And the Kinetic Energy formula then reared its head, as it is now.

A detailed study on the "optimum break weight" (APAPP, Ron Shepard) has shown no bearing on the mass relation between one's shooting cue and break cues. None. The optimum break cue weight is determined by the muscles involved in the individual breaker's technique. That may result in a weight lighter or heavier than the individual's shooting cue weight my happenstance. It could be more or less than 19 oz.

Fred

I'd like to read the study you are referencing. I read Mr. Shepard's paper on tip end mass and its effects on squirt. While he demonstrates there is a connection, he does not demonstrate that is is the only factor.

Breaking cue weight may not be the primary consideration, but it does nonetheless have an effect. It's all just applied Physics.

 

[StormHotRod300]

Ok heres a quick update

Tonight i went to the pool hall tonight and was going to practice a bit with a friend and the owner (Fred) has a 21oz PFD w/ phenolic ferrule/tip, and i used it to break with on a 9ft table.

And first break with no warm up, i crush the rack make 3 balls and squat the CB in the middle of the table and run the rack. Next rack, i break make two balls, squat the CB, but it gets kicked by another ball and i end up pushing out.

And this was a continuous theme for the whole time we was practicing. I wasnt breaking any harder that what i would do with my 18oz break cue, and had more success.

Needless to say, after this practice session, i went and added as much weight to my Sneaky Pete break cue as i could, which brings it upto about 22oz's and had a phenolic ferrule/tip combo put on it too.

dave

 

[Icon of Sin]

Did you guys see those Lightning Bolt break cues they were selling at the Univeral Smart Shaft booth. They only weighed 12oz. I saw 12yr old kids breaking as hard as grown men with them. I held one that some kid let me look at as he bought one. Extremely light, I didnt get a chance to break with it though.

I couldnt believe how light it was 12OZ... insane!!!

 

[The Piper]

I don't think this is a valid comparison. The aluminum has some clear advantages that don't apply to pool. For starters, you need a quick swing in baseball, because you have to be able to read the pitch, make a decision, start your swing, and get the bat over the plate as the ball is arriving. If the swing is slow, the read and the decision has to be faster, otherwise you'll be swinging behind the ball. This timing is not a factor in pool.

Also, the aluminum bat compresses more at contact, giving a longer contact and an increased ball speed, almost like the strings of a tennis racket. This is not related to its weight.

As far as cue speed goes, a lighter cue will go faster given the same amount of work done by your arm. But it has the same momentum (according to newton) as a heavier and slower cue would, given the same amount of work done by your arm. And it's transfer of momentum that gets the cue ball moving. So the weight actually cancels out in the ball-speed equation. What's really important is the transfer. Given a fast-light and a slow-heavy stick with equal momentum, the one that transfers more of its momentum at contact is the one that hits the cue ball faster. This has to do a huge number of factors, including but not limited to cue contruction, taper, tip material, ferrule material, accuracy of tip placement on the cue ball, etc.

My take on it is that the slower/heavier stick will be easier to control, because it moves slower. The acceleration of a heavier stick, again given equal arm work, will be smoother and more controlled, in my opinion, because your arm won't be moving as quickly. But as far as stick momentum, stick mass cancels out of the equation, given equal work performed by the arm.

-Andrew

Dang.

I just hit the darn thing then run em out.

 

[Cornerman]

I'd like to read the study you are referencing. I read Mr. Shepard's paper on tip end mass and its effects on squirt. While he demonstrates there is a connection, he does not demonstrate that is is the only factor.

"Connection" is quite an understatement.

Breaking cue weight may not be the primary consideration, but it does nonetheless have an effect. It's all just applied Physics.

The discussion of optimum break cue weight can be found under Section 3.Cue Tip/Cue Ball Impact, pp 23-24 of Amateur Physics for the Amateur Pool Player. The paper can be found at Bob Jewetts site:

http://www.sfbilliards.com/Shepard_apapp.pdf

In a nutshell, the higher the body mass you use on your break, the higher the optimum mass of the cuestick. The resultant optimum weight (~15-24 oz) spans a range that starts lower and ends higher than the standard range of shooting cues (~17-21oz).

Fred

 

[jsp]

The discussion of optimum break cue weight can be found under Section 3.Cue Tip/Cue Ball Impact, pp 23-24 of Amateur Physics for the Amateur Pool Player. The paper can be found at Bob Jewetts site:

http://www.sfbilliards.com/Shepard_apapp.pdf

In a nutshell, the higher the body mass you use on your break, the higher the optimum mass of the cuestick. The resultant optimum weight (~15-24 oz) spans a range that starts lower and ends higher than the standard range of shooting cues (~17-21oz).

Thanks for the link Fred.

I read that section very briefly, and I think the paper actually does give support to the "lighter is better" argument. For the entire range of forarm masses (24oz to 64oz), the optimum cue weight is between 13.2oz to 19.3oz, whose average is definitely on the light side (16.75oz).

He does say that if someone uses his entire arm by "pivoting at the shoulder", the entire arm mass would be 150oz and thus have an optimum stick weight of 27.2oz. Although this might satisfy his equations, I don't think this number is at all accurate with practical data. Many people break with their entire arm, and i don't think anyone would consider using a 27.2oz cue. I believe his models and equations break down at this point. I have to examine the paper more thoroughly.

I still say that it's mainly about cue speed. The faster you can accelerate the cue the better, and a lighter cue in general would achieve this.

 

[Cornerman]

Thanks for the link Fred.

I read that section very briefly, and I think the paper actually does give support to the "lighter is better" argument.

Wow. He wrote an awful lot to give quite a bit of information to actually not say this. I guess it's how you read it. I read it thoroughly probably a hundred times over the past several years. The bottom line is that relating weight as lighter or heavier is really meaningless, and that there is an optimum break cue weight that could be lighter or heavier. That is, an absolute number is more important than a relative number.

He does say that if someone uses his entire arm by "pivoting at the shoulder", the entire arm mass would be 150oz and thus have an optimum stick weight of 27.2oz.

This was just an example using arbitrary weight and doing the calculation.

To actually put a number on how much body mass is involved in a break shot is the same as putting a number as to how much mass is involved to cause squirt. You can reverse calculate it to a degree, but it's tough to say where all the mass came from.

So, if you can effectively use mass from your body into the break shot, then the optimum weight of the cue is the one that jibes with the effective mass from the body. But, that's an iterative process. Once you change the weight of the cue, your effective use of mass from the body changes as well. That then points simply to getting a cue that feels comfortable during the break shot, and maximize your effort with it.

That is to say, there's sufficient evidence in both the real world and by physics to dismiss the simple saying "lighter is better because you can get a higher velocity" as nothing more than a simple saying.

Fred