Speaking of cue weight.... Any science to it?

ddadams

ddadams

Absolutely love this cue.
Silver Member
So I've been wondering about this for a while..

Does cue weight have an effect on ball speed given same speed of stroke? I would assume it does but I can't manually test this as I don't have proper equipment.

I would assume that hitting a ball at just 5 mph with a 21 ounce cue would produce a bit more speed than a 17 ounce cue, but I'm not sure?

I'm wondering if a heavier cue might be better for me rather a light cue mainly as I feel with a heavier cue and the shots that require the utmost of speed control (mainly for safeties) having a naturally slower stroke due to the weight may help.

But if the force of the extra weight would have an effect then I'll just have to learn to hit excruciatingly soft on demand. Most of the time I can but some shots require the touch of an ant as you all know and its a bit more challenging.
 
I've heard its about acceleration, Lighter cue = more momentum and acceleration thus creating a more powerful break. You will never change the weight of a cue ball and the power going into a break just but using a heavier cue, the only thing is it just may take less effort into the break stroke.
 
When the balls were clay and table cloths slower, the average cue length was 57" and 21 ounce was typical. Phenolic balls, faster Simonis 860, and more snooker like stance cues are now 59" and 19 ounces or less are the norm. I wouldn't be surprise if cues get longer, and lighter.
 
ddadams said:
Does cue weight have an effect on ball speed given same speed of stroke?
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Yes, conservation of momentum says mass 1 x velocity 1 = mass 2 x velocity 2. So, 21 ounce cue stick x 5 mph swing = 6 ounce cue ball x 17.5 mph ball speed; and, 17 ounce cue stick x 5 mph swing = 6 ounce cue ball x 14.1 mph ball ball speed.

But, none of these numbers explain what makes executing a shot easier. For example: A shot that requires a soft touch may be more difficult to properly execute if you're swinging a very heavy cue because you'd have to hold back that extra weight.
 
ddadams said:
Does cue weight have an effect on ball speed given same speed of stroke?
Click to expand...

I'm going to go with :: Mostly No.

Most of the weight (16 out of the 19 oz) are in the but of the cue.
The impact compression wave has not reached the but of the cue by the time the CB has left contact with the tip.

I suspect that the weight of the first 6 inches can (have a small) effect the speed of the CB, but the weight of the but is almost completely out of the question.

Then if you apply any of the F=M*a stuff, you find that the heavier the cue, the lower the velocity is when you make contact with whitey.
 
It is an excellent question, though you may not find consensus. Randy Mobley had strong opinions about weight and suggested correct weight is based upon the player. Harvey Martin certainly believed in customizing weight. I've found balance to be a much more predictive element than actual weight personally.

Mike Sigel played 9 ball with me in 1988 and after utterly dismantling any hope I had to win so much as a single game, he showed me a few things. His cue was 18 oz and his argument was that the lighter cue was easier to use over an extended period of play. Balkline requires a highly refined speed control. Players need to hit very soft shots. Cues for that game tend to be as light as 14 oz and almost always are lighter than traditional pool cues. So I would say the game will determine, to a degree, the appropriate weight of a cue.
 
jschelin99 said:
Yes, conservation of momentum says mass 1 x velocity 1 = mass 2 x velocity 2. So, 21 ounce cue stick x 5 mph swing = 6 ounce cue ball x 17.5 mph ball speed; and, 17 ounce cue stick x 5 mph swing = 6 ounce cue ball x 14.1 mph ball ball speed.

But, none of these numbers explain what makes executing a shot easier. For example: A shot that requires a soft touch may be more difficult to properly execute if you're swinging a very heavy cue because you'd have to hold back that extra weight.
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This is incorrect. You know enough about the conservation of momentum to do the math, but not enough to use it properly in this example. Just think about the numbers you wrote. Swinging a super heavy house cue at 5mph does NOT give you a break speed of 17.5 mph, not even close.

I don't know enough to explain the application of the equation here, but know this application is incorrect. I believe it has to do with the cue ball only "sees" part of the mass of the stick, not the mass of its entire length.
 
I don't know about the science stuff but I play with a 15oz cue for 3Cushion. Hitting larger balls 5 to 8 rails after hitting ball 1 is not a problem on a 10' table.

Of course making the shot is another story. But how hard or what speed do you need to break a rack?? I'd guess not much harder or faster than max distance 3C shots. Suppose you could say Simonis 300 is much faster than 860 for instance. But still??
 
While I'm not really concerned with the break here I was mainly wondering this for super soft shots.


Thanks for all of your feedback so far. I wasn't really considering balance point meaning as much as it probably does. I'm getting an 18 oz cue that has a balance point an inch and a half up where my Joseys is next week or the week after so I can't wait to try that out.

I love my Josey but I feel like it really is quite light in the front for how small my armspan is. I'm pretty short so a typical 19" balance point wasn't really working for me. We'll see how I like the closer point/lighter weight I guess.


Just wondering if I should even switch after how used to this cue I am already but I gotta see if the lighter weight helps at all. Or the balance.


Danny
 
DoubleD said:
Balance point doesn't mean a thing from the physics standpoint in this case. The centroid of the cue will always be in line with the stroke, so it doesn't come into play at all.

dld
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I know unrelated just rambling.

But the weight question has still been in my head for a while just haven't gotten around to posting about it until tonight.
 
DoubleD said:
For one, you are completely neglecting the fact that the cuestick is still moving and, in fact, never stops moving during a hit.
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Actually I believe it does come to a complete stop at the moment of impact, except in so much as the tip compresses. A phenolic tipped cue comes pretty darn close to a dead stop at the moment of impact. Watch some of those Dr. Dave videos...


KMRUNOUT
 
ddadams said:
While I'm not really concerned with the break here I was mainly wondering this for super soft shots.


Thanks for all of your feedback so far. I wasn't really considering balance point meaning as much as it probably does. I'm getting an 18 oz cue that has a balance point an inch and a half up where my Joseys is next week or the week after so I can't wait to try that out.

I love my Josey but I feel like it really is quite light in the front for how small my armspan is. I'm pretty short so a typical 19" balance point wasn't really working for me. We'll see how I like the closer point/lighter weight I guess.


Just wondering if I should even switch after how used to this cue I am already but I gotta see if the lighter weight helps at all. Or the balance.


Danny
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This might speak directly to your question. I recently had an extension made for my cue that goes between the shaft and the butt. It is 4", and weighs just over an once. I experienced a noticeable change in the action I got out of the cueball. When I swung with my normal stroke, I definitely seemed to get a little more action out of the ball. It seemed more effortless to achieve medium and soft draw at a distance when stroking at a soft speed. I can't explain the physics behind it, but this is the difference I noticed. I can't say I noticed any significant difference in my very soft speed control. I mean, I'd say it improved...but I would attribute this more to the improved fluidity of my stroke resulting from a cue that is more properly fit to my size (I'm almost 6'3" with long arms).

Hope this helps,

KMRUNOUT
 
The simple problem (without inelasticity and such) is one that any bright high school student should be able to solve. The formula is given on page 37 of Robert Byrne's "Advanced Technique in Pool and Billiards" in the chapter titled "Searching for the Perfect Break Cue". He describes the formula in words but here is a simple equation:

Vball = Vstick * 2 * Wstick / ( Wstick + Wball )

Where Vstick is the speed (velocity) of the stick just before it hits the ball and W means "weight of". Example: for an 18-ounce stick and a 6-ounce ball and the stick coming in at 10MPH the formula says:

Vball = 10MPH * 2 * 18 / ( 18 + 6 ) = 15MPH

So, the simple theory predicts that the cue ball will be going about 50% faster than the cue stick. After impact, the cue stick in the above example will have slowed to 50% of its initial speed.

All of this stuff has been measured. A long time ago Professor A. D. Moore wrote an interesting paper on Willie Hoppe's stroke and as part of the preparation measured the "efficiency" of the tip-ball collision. The number he got instead of the theoretical 150% was 130% for ball speed. The imperfect nature of the tip and possibly shaft eat up some of the energy.

Phenolic tips are better for break cues than leather tips because they lose less than that 20% during contact.
 
Some other examples are interesting. If the stick weighs 500 pounds, you can plug in the numbers and see that the cue ball will be going very close to twice as fast as the stick and if you increase the weight to 50,000 pounds the ball speed will remain very close to twice as fast as the stick.

If the stick is equal to the weight of the ball, the result (for a perfect tip) is 100% of the speed, and the stick should stop dead on collision.

A further point is that the flesh of the hand is so soft (compared to compressed leather or phenolic and wood) that the weight of your arm does not actually participate in the collision.
 
ddadams said:
So I've been wondering about this for a while..

Does cue weight have an effect on ball speed given same speed of stroke? I would assume it does but I can't manually test this as I don't have proper equipment.

I would assume that hitting a ball at just 5 mph with a 21 ounce cue would produce a bit more speed than a 17 ounce cue, but I'm not sure?
.
Click to expand...
Answer is yes using the standard linear collision equation for two objects and conservation of momentum.

Freddie <~~~ see Bob Jewett's answer
 
ddadams said:
So I've been wondering about this for a while..

Does cue weight have an effect on ball speed given same speed of stroke? I would assume it does but I can't manually test this as I don't have proper equipment.

I would assume that hitting a ball at just 5 mph with a 21 ounce cue would produce a bit more speed than a 17 ounce cue, but I'm not sure?

I'm wondering if a heavier cue might be better for me rather a light cue mainly as I feel with a heavier cue and the shots that require the utmost of speed control (mainly for safeties) having a naturally slower stroke due to the weight may help.

But if the force of the extra weight would have an effect then I'll just have to learn to hit excruciatingly soft on demand. Most of the time I can but some shots require the touch of an ant as you all know and its a bit more challenging.
Click to expand...

You need to start somewhere, there is no simple answer and No quick fix to your concern. I'm 6'6'' and prefer short light cues, many think I need a long cue, tried that with my Szamboti for ten years, didnt work for me, but keep in mind I played 40 hrs a week for at least thirty years straight.

My biggest concern would be having the weight that I feel comfortable with.... but the cues ''balance'' and the feel of it being balanced properly would be my biggest concern. If you don't have the ability to determine this, take a real Player with you and have em hit balls with it to get your feedback. No matter what cue ya own, if its balance is like a club (too much rearward weight) or to too much forward weight don't go there. I'm not talking about balance point, but the weight of the cue being not too forward or too rearward, and basically unnoticeable during play.
 
DoubleD and others: yes, you're right that I used the incorrect equation. Nor will I try to argue the math with you. You've always proven (to me at least) that you know what the heck you're talking about.

I wasn't truly meaning to get to the nitty gritty of the science of a shot. I was just trying to quickly answer the OP's question that a heavier cue swung at the same speed makes a difference.

However, I believe the crux of the OP's question was whether a heavier cue was "better" on a certain shot, or if a lighter cue made shooting a soft shot "easier." Those concepts are, of course, subjective. Therefore, there's not really a "correct" answer to that question.
 
I know the OP was not going for break cues after his follow up post, but it seems the thread headed that way... Here is a continuation on that thought:

You know, now that we can all get a super accurate radar gun on our phones for $5, using that app for choosing a break cue weight would be a good experiment.

Everyone probably will have a specific weight that would work best for "them". Maybe go to the local room with the house cues on the wall. They will probably all have the same tips on them. Try 10 breaks with 16 through 22 oz cues, and record your results. Throw out any miscues so they don't skew the results. See if you can find any trends for your specific situation.

Then, if you find one weight cue does work best for you, see if you can make your dedicated break cue that same weight.
 
What I believe can be derived from this if you're seeking to increase CB speed, you're going to gain more by lowering cue weight if in doing so you increase cue stick velocity (assuming of course you gain more than 1 mph of cue stick speed for every 1 ounce of cue stick weight reduction). My personal experience shows this to be the case. At the same time, there is a point of diminishing returns. I'm thinking that would be the point where going lighter with the cue doesn't enable the shooter to move the cue stick any faster.

This makes sense and explains why the optimal break cue weight is going to vary from person to person.

As to the OP original question, I think cue weight for normal playing is mostly a factor of personal preference. For mr, balance is more important. I do not like a butt heavy cue regardless of the weight. I prefer a balanced cue around 19.2 ounces.


Bob Jewett said:
The simple problem (without inelasticity and such) is one that any bright high school student should be able to solve. The formula is given on page 37 of Robert Byrne's "Advanced Technique in Pool and Billiards" in the chapter titled "Searching for the Perfect Break Cue". He describes the formula in words but here is a simple equation:

Vball = Vstick * 2 * Wstick / ( Wstick + Wball )

Where Vstick is the speed (velocity) of the stick just before it hits the ball and W means "weight of". Example: for an 18-ounce stick and a 6-ounce ball and the stick coming in at 10MPH the formula says:

Vball = 10MPH * 2 * 18 / ( 18 + 6 ) = 15MPH

So, the simple theory predicts that the cue ball will be going about 50% faster than the cue stick. After impact, the cue stick in the above example will have slowed to 50% of its initial speed.

All of this stuff has been measured. A long time ago Professor A. D. Moore wrote an interesting paper on Willie Hoppe's stroke and as part of the preparation measured the "efficiency" of the tip-ball collision. The number he got instead of the theoretical 150% was 130% for ball speed. The imperfect nature of the tip and possibly shaft eat up some of the energy.

Phenolic tips are better for break cues than leather tips because they lose less than that 20% during contact.
Click to expand...
 
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