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View Full Version : Billiard Cue weight and BP question



04-15-2002, 12:33 PM
Does anybody who plays Carom billiards know what is the average weight of a billiard cue for "straight rail or 3C" and if it's more forward or rear balance?

04-16-2002, 08:33 AM
Hmmmm... I'm curious, too.

Alfie
04-16-2002, 07:49 PM
Quote Anonymous: "Does anybody who plays Carom billiards know what is the average weight of a billiard cue for "straight rail or 3C" and if it's more forward or rear balance?"

Here is some information Deno Andrews shared with me. We didn't talk about balance points. He recommended Mike Lambros as a carom cuemaker.

weight range- 16oz to 19/20oz

common weight- 18oz

length range- 55" to 57"+

common length- 56"

shaft material- Maple

tip size range- 10mm-13.5/14mm

common tip size- 12.5mm

tip curvature- same as the ball which is 61.5mm diameter
[this is just his opinion of what it should be- Alfie]

common tapers- constant, wedge ... only two worth anything IMHO. Constant goes in a straight line from the tip size to the butt size ... while wedge has two constant tapers ... one in the shaft and one in the butt. [he preferred the hit of the constant- Alfie]

TonyM
04-17-2002, 10:36 PM
I'd say that a typical carom cue would weigh about 18 ounces +/- 1 ounce. Most are less than 19 ounces though. As for balance, most of the carom cues that I have played with (or built for that matter) would have what would be considered a rearward balance to a pool player. Dennis Dieckman comments on this on his web site. The idea is that many shots in pool require a low hit on the cue ball to kill it. So a forward balance helps to keep the cue tip low. While many carom shots require the cueball to run, so they are struck higher. Consequently the balance point is farther back. I'm not certain about the validity of this idea, but there it is for what it's worth.

Keep in mind when comparing balance points that the balance should be measured from the tip, not the butt. This is because a carom cue is usually about 2" to 3" shorter than a pool cue, so if you measure the BP from the butt you will be comparing apples to oranges.

Tony

04-18-2002, 12:03 AM
<blockquote><font class="small">Quote: Keep in mind when comparing balance points that the balance should be measured from the tip, not the butt. This is because a carom cue is usually about 2" to 3" shorter than a pool cue, so if you measure the BP from the butt you will be comparing apples to oranges.Tony [/quote:</font><hr>

tony, now i'm confused. the cue is 2-3" shorter but only, maybe, an ounce lighter than a regular pool cue? seems like they're putting some weight back into the cue. izzat true?

dan...and why.

TonyM
04-18-2002, 12:33 PM
Yes the cues are shorter, and yes they are only 1 or two ounces lighter. But this does not neccessarily mean that they put more weight in the back (although generally this is true). Basically, the shafts are shorter. A few inches of 12mm maple does not weigh very much does it?

Another difference with Billiard cues is that the butts are often a conical taper from joint to butt cap. Many pool cues use a series of tapers with the forearm having the steepest taper, the handle the next steepest, and the butt sleeve is often parallel (or close to it).

Billiard cues almost never use a linen wrap. Many 3C players use a rubber wrap and grip the cue very lightly.

Did I mention that 3c cues use a very short ferrule (1/4" to 3/8" long) and are naturally low squirt cues?

Tony

Troy
04-18-2002, 02:23 PM
And that the taper on most Carom/Billiard cues is a "straight taper", conical from the tip on back.

<blockquote><font class="small">Quote: TonyM:</font><hr> Yes the cues are shorter, and yes they are only 1 or two ounces lighter. But this does not neccessarily mean that they put more weight in the back (although generally this is true). Basically, the shafts are shorter. A few inches of 12mm maple does not weigh very much does it?

Another difference with Billiard cues is that the butts are often a conical taper from joint to butt cap. Many pool cues use a series of tapers with the forearm having the steepest taper, the handle the next steepest, and the butt sleeve is often parallel (or close to it).

Billiard cues almost never use a linen wrap. Many 3C players use a rubber wrap and grip the cue very lightly.

Did I mention that 3c cues use a very short ferrule (1/4" to 3/8" long) and are naturally low squirt cues?

Tony <hr></blockquote>

Alfie
04-18-2002, 07:51 PM
Quote TonyM: "As for balance, most of the carom cues that I have played with (or built for that matter) would have what would be considered a rearward balance to a pool player. Dennis Dieckman comments on this on his web site. The idea is that many shots in pool require a low hit on the cue ball to kill it. So a forward balance helps to keep the cue tip low. While many carom shots require the cueball to run, so they are struck higher. Consequently the balance point is farther back. I'm not certain about the validity of this idea, but there it is for what it's worth."

This explanation is BS, myth, or bad science, IMO. The balance point has no affect on the ability to hit any aim point on the ball. Please, do not repeat this stuff. :-)

04-18-2002, 09:15 PM
<blockquote><font class="small">Quote: Alfie:</font><hr> Quote TonyM: "As for balance, most of the carom cues that I have played with (or built for that matter) would have what would be considered a rearward balance to a pool player. Dennis Dieckman comments on this on his web site. The idea is that many shots in pool require a low hit on the cue ball to kill it. So a forward balance helps to keep the cue tip low. While many carom shots require the cueball to run, so they are struck higher. Consequently the balance point is farther back. I'm not certain about the validity of this idea, but there it is for what it's worth."

This explanation is BS, myth, or bad science, IMO. The balance point has no affect on the ability to hit any aim point on the ball. Please, do not repeat this stuff. :-) <hr></blockquote>

ALFIE?????? What a gay name. LOL

TonyM
04-18-2002, 10:28 PM
As I said Alfie, I make no claims as to the validity of the claim, only that some players and cue makers do believe it. A case could be made that a radical change in balance point can affect where you are comfortable holding the cue. This could affect your ability to hit a consistent aim point imo. Also, try holding a cue very near the balance point and drawing the ball with an open bridge. The cue becomes unstable and is hard to keep down. While an extreme example to be sure, it does suggest that balance point is not totally irelevant.

Tony

TonyM
04-18-2002, 10:32 PM
"And that the taper on most Carom/Billiard cues is a "straight taper", conical from the tip on back"

My father used to have a fit if I called anything a "straight taper" Lol! His reasoning was that by definition, a "taper" is a constant change in diameter, or a cone. Otherwise is it something else and not a taper. But my reasoning was to distinguish between a "compound" or series of varying tapers.

Tony

Alfie
04-19-2002, 06:47 AM
Quote TonyM: "As I said Alfie, I make no claims as to the validity of the claim, only that some players and cue makers do believe it."

I understand so I'm arguing against the idea, not against you. Don't feel you have to rebut.

Unless you are shooting one-handed the tip height is determined completely by the bridge height. The bridge hand is strong enough to support the small amount of weight on it at any height on the cue ball.


Quote TonyM: "A case could be made that a radical change in balance point can affect where you are comfortable holding the cue. This could affect your ability to hit a consistent aim point imo."

But this is a different discussion. To isolate DD's balance point claim let us first assume a player with good and consistent technique no matter where the balance point is. Consistent technique means the same bridge length (for the same shots), same stance, and same stroke.


Quote TonyM: "Also, try holding a cue very near the balance point and drawing the ball with an open bridge. The cue becomes unstable and is hard to keep down. While an extreme example to be sure, it does suggest that balance point is not totally irelevant."

Again this is a different discussion. If the balance point of his cue is close enough to the back hand that he has tip control problems using an open bridge then the cue is a bad fit. It is not good cue for him in any cue sport discipline. He would need to get the balance point moved up or get a different cue. Only when there is no tip control problem can DD's balance point claim be examined.

stickman
04-19-2002, 07:24 AM
<blockquote><font class="small">Quote: TonyM:</font><hr>
Keep in mind when comparing balance points that the balance should be measured from the tip, not the butt. This is because a carom cue is usually about 2" to 3" shorter than a pool cue, so if you measure the BP from the butt you will be comparing apples to oranges.

Tony <hr></blockquote>

This confuses me. Not that I don't believe that you know what your talking about at all. I'm just not sure I understand the reasoning for measuring from the front. If you are comparing std. 58" cues, I can't see where it would make any difference whether you measured from the front or the rear as long as you specify which end the measurement is taken from. If you are measuring different lenght cues, as you say, you are comparing apples to oranges. I would think this would be the case whether you measured from either end. This must be a common error, because I've seen many references to balance points measured from the rear. I'm guessing that because it's a shorter measurement, this is the reason many people use it.

TonyM
04-19-2002, 10:25 AM
Here is the reasoning behind it. When we pick up a cue, the distance from the tip to our bridge hand is fixed by our preference, and the distance between our bridge hand and grip hand is fixed by our skeletal structure (and stance). But the distance that hangs out behind our grip hand is essentially dead weight.

So let's say you have two cue, one is a standard 58" cue with a balance point 19.5 " from the butt. The other is a 55" cue, with a standard length shaft, but a short butt. The balance point for this cue is 16.5" from the butt.

Now do they actually have a different balance point?

I say no they don't. Both cue are balanced at 38.5" from the tip. If you use the same bridge length, then the balance point will be located the same distance from your grip hand. If the cues weight the same, and have the weight distributed in a similar manner, then you will feel the same amount of weight on your bridge hand and in your grip hand. The only difference will be how much cue is hanging out behind your grip hand. While this extra length can affect your abaility to reach for a shot, it doesn't normally affect how you feel the balance of the cue.

So comparing two cues of different lengths by measuring the balance point from the tip is not comparing apples to oranges after all.

By the way, I like to see how much weight is at the bridge fulcrum and how much weight is at my grip hand when comparing cues. I think that this "means" more than just comparing balance points and weights. I like to feel 4.5 to 5 ounces on my bridge hand if anyone is interested. (regardless of the weight of the cue! For bonus points, what does that tell you about the balance point?)

Tony

TonyM
04-19-2002, 10:35 AM
Essentially I agree with you. The question is whether or not there is an optimum balance point for hitting a ball high or low. DD says that a forward BP is better to hit the ball low, while a rearward BP is better to hit the ball high.

At the extremes (very far forward BP and very far rearward) I think that he may be right. This implies that there will be an optimum BP (based on bridge length and grip hand position, not cue length) that is a perfect compromise for both situations.

I was taught to move my grip hand back slightly for power draw. In effect, this moves my grip hand back relative to the balance point and puts more weight on my bridge hand.

I also see some pros do the same (without a longer bridge), so the idea is not without some possible merit.

I think that this idea is based more on "feel" than anything else. A forward BP, gives a feel of more weight on the bridge hand and this might "feel" more natural when aiming at the bottom of the ball (at least with an open bridge).

But the whole issue might just be a preference effect, rather than a real phenomena.

Tony

stickman
04-19-2002, 10:48 AM
Sorry Tony, I won't get any bonus points. I'm still scratching my head over that one. Thank you for the explaination. It makes sense to me now.

Alfie
04-20-2002, 06:47 AM
Quote TonyM: "DD says that a forward BP is better to hit the ball low, while a rearward BP is better to hit the ball high. At the extremes (very far forward BP and very far rearward) I think that he may be right."

IYO- Where are the extremes? Why is an extreme forward BP better to hit the ball low? Why is an extreme rearward BP better to hit the ball high?


Quote TonyM: "I was taught to move my grip hand back slightly for power draw. In effect, this moves my grip hand back relative to the balance point and puts more weight on my bridge hand."

How far back? Do you move the front hand back too? the same amount?

clarence
04-20-2002, 04:45 PM
Tony

When considering the BP of a cue in relation to your grip location , what do you think is a good distance that the grip hand be behind the BP for cue stability when elevating the cue on rail shots or jump shot with either overhand or dart grip with your regular cue

Does it follow that a forward weighted cue is also forward balance or is it possible to have a forward weighted cue that is backward balance as in 17" balance point from butt cap ?

stickman
04-20-2002, 05:35 PM
I can draw a ball as good or better than most of the local players with my rearward balance stick. I can sure draw a ball better with it, than with my other stick that is more forward balanced. I have trouble with follow, but that may be the shooter more than the stick. I've been working on it and it's getting better, but I still will draw a ball over following, given a choice.

TonyM
04-20-2002, 11:03 PM
To see how far fprward or how far rearward an extreme balance point could get, I built a special adjustable cue that allowed me to move the balance weights forward, to the center of the butt, to the actual balance point itself, or rearward. I could set a forward balance point that was just a few inches back from the joint, and a rearward balance point that was in the middle of the wrap area. At those extremes (much farther forward or rearward than any production cue I might add) aome strange things happened.

At the very far forward position, it became very difficult to even make a ball! The back of the cue became unstable. At the very rear position it was very difficult to draw the ball (the tip wanted to come up badly).

As for the comment on grip position, I move my hand back about 1" (sometimes less). I try not to move the bridge hand forward. The idea is to make sure that the rear arm is vertical at address so that the ball is struck when the cue is at the bottom of the pendulum. I want to get a full follow through at least 4" to 6" past the cueball for a power draw shot.

Tony

TonyM
04-20-2002, 11:19 PM
Actually Clarence, I think that the grip hand position is basically set by the mechanics of the shot, and the physical layout of the player. You want to try and have the back arm perpindicular to the cue at address, even if the cue is elevated. So on a rail shot, you choke-up on the cue (hold closer to the forearm) and use the bridge length that is set by the constraints of the rail position. This determines the rear hand position. Therefore, the distance of the rear hand from the balance point becomes a function of where the balance point is on the cue. I don't consciously choose a hand placement for these types of shots based on balance point. But Ideally, you want perhaps about 4" between the BP and the grip hand so that the tip stays down on rail shots. For very short players, this might require a cue with a far forward balance point.

I have a different way of looking at balance in cues. I never use the terminology "forward weighted" or "rearward weighted" as I believe that it is both misleading, and incorrect.

How much weight is felt in the grip and bridge hand (which can give the "impression" of forward or rearward weighting) is really a function of the overall weight of the cue, the balance point, and the position of the grip hand. Move your hand farther back on the cue and it "feels" more forward weighted. And yet nothing has actually changed on the cue.

So to me the balance point is simply what it implies. It is the place where the cue balances. Nothing more or less. How the weight of the cue is distributed is a different story however. It is possible to maintain a balance point, but distribute the majority of the weight to the front, to the rear, or at the balance point itself, or evenly throughout the butt (within the weight limit and based on the density of the materials of course).

The distribution of the weight effects the way that the cue behaves dynamically when swerved from side to side while stroking fore and aft. This is called the "moment of inertia". Maximizing the moment of inertia resists any accidental swerves or swoops in the stroke. This effect is completely independant of the balance point and the concept of "forward" or "rearward" weighting (which is really based on the distance of the grip hand from the balance point). The distribution of the weight is really what is responsible for that feeling of a perfectly "balanced" cue, not the balance point itself.

Tony

stickman
04-21-2002, 01:37 AM
Tony, could the reason I am able to get more draw with my slightly rearward balanced stick be due to the 12mm tip? In a post here a long time ago, I posted that I could get more english with my 12mm shaft, and was told the tip size has no effect on the amount of english you can apply. All I know for sure is that I can draw a ball further with this stick than any standard stick I've used.

Alfie
04-22-2002, 12:33 AM
Quote TonyM, the mad scientist of cuemaking: "To see how far forward or how far rearward an extreme balance point could get, I built a special adjustable cue that allowed me to move the balance weights forward, to the center of the butt, to the actual balance point itself, or rearward. I could set a forward balance point that was just a few inches back from the joint, and a rearward balance point that was in the middle of the wrap area. At those extremes (much farther forward or rearward than any production cue I might add) some strange things happened.

"At the very far forward position, it became very difficult to even make a ball! The back of the cue became unstable."

Alf- This would be left/right instability due to the lack of heft in the back hand. I'm guessing you had a shaft with an spp significantly different from your bridge length on that contraption. But this instability would adversely affect both top and bottom spin shots, hence "it became very difficult to even make a ball!"

Quote TonyM: "At the very rear position it was very difficult to draw the ball (the tip wanted to come up badly)."

Alf- Didn't the tip want to come up badly with top spin, too?

In both of these cases the problem is one of tip control. It is preferable to have the BP as far back as possible to increase the moment of rotation about the bridge hand, minimizing left/right instability; but it can't go past the point where tip control problems appear when using an open bridge. So there is a point or a range (which one it is is not important) that is ideal for a BP, however, it has nothing to do with low or high spin.

IMO

04-22-2002, 09:40 AM
<blockquote><font class="small">Quote: TonyM:</font><hr>
Did I mention that 3c cues use a very short ferrule (1/4" to 3/8" long) and are naturally low squirt cues?

What you describe has been my experence also. I use a Schuler cue, the shafts I use most are 12mm (7/16" ferrule) and 12 1/2mm (1/2" ferrule). The 12mm requires little or no correction for squirt. The 12/1/2mm requires only slight correction, I believe this is due to it having a pro taper.

Tony <hr></blockquote>

TonyM
04-22-2002, 02:31 PM
"Alf- This would be left/right instability due to the lack of heft in the back hand. I'm guessing you had a shaft with an spp significantly different from your bridge length on that contraption. But this instability would adversely affect both top and bottom spin shots, hence "it became very difficult to even make a ball!" "

Actually, the pivot point was intentionally long, so that the effect would be exagerated. Good for you to notice the possibility!
And yes the basic cause of the instability was a loss in moment of inertia. This shows up in both a "yaw" axis (rotation about the bridge left or right) and in the vertical direction.

"Alf- Didn't the tip want to come up badly with top spin, too?"

Yes it did. The same sort of problem exists with this solution. A reduction in moment of inertia, compounded by a feeling of "weightlessness" on the bridge hand. The shaft felt "directionless" like it was waving around in the air. Not very scientific, but an apt description of the sensation for me.

"In both of these cases the problem is one of tip control. It is preferable to have the BP as far back as possible to increase the moment of rotation about the bridge hand, minimizing left/right instability; but it can't go past the point where tip control problems appear when using an open bridge. So there is a point or a range (which one it is is not important) that is ideal for a BP, however, it has nothing to do with low or high spin. "

Actually, I don't think that it is neccessarily desirable to have the balance point as far back as possible. The idea with this approach is to have the extra heft in your back hand provide a feedback due to gravity. While this is one way to provide a feedback, it is by no means the only way (or the preferable way imo). The other way is to distribute the weight as far apart as possible (sort of like a bar- bell, or tight-rope walker pole effect).

This way, the moment of inertia about the bridge hand is maximized. The effect can even be quantified, by assuming a known amount of torque about the bridge hand (due to a stroke error) and comparing various weight distributions and calculating the actual final stroke angular error. Mike Page did this on RSB a few years ago, and the best results (least amount of angular error) were for a weight distribution that employed the balance weights separated by as much distance as possible. This meant that some of the weight was in the very rear of the cue, and some was toward the front (but not so far that it adversely affected squirt!).

This idea is exploited in Russian Billiard cues. They are very long (often 64" +) and very heavy (often 27 ounces!) and a lot of lead weight is added to the front and rear of the cue to maximize the moment of inertia. It took me some time to figure out why they were doing this (and it isn't clear if the cues "evolved" to this solution by trial and error, or by design). Russian Billiards are played on a Snooker sized table, with very large balls (over 2.5") and with pockets that are only 3mm or 4mm larger than the ball diameter! So potting is very difficult! Hence the cues are designed to minimize any stroke errors. The best of these cues do not have most of the weight in the rear of the cue.

Tony
-mad scientist, I like that!....

TonyM
04-22-2002, 02:41 PM
I posted a reply to the smaller tip = more spin myth in the other thread about balance point Stickman. Suffice to say that no, I don't beleive that you can get more spin with a smaller tip. In general, the spin verus shaft displacement is affected only by the tip curvature itself, not the diameter. Does your 12mm shaft have the same curvature as your 13 mm shaft?

The other factor is a visual one. It is easier to be precise with tip placement with a smaller tip diameter. 3C players use this idea (so do Snooker players). This is because the perception of the intended tip/ball contact point is closer to the actual tip/ball contact point with a smaller tip than with a larger tip. Imagine a tip that went down to a coplete point. the percieved contact point would equal the actual contact point. Now imagine a tip with a 2" diameter. The intended contact point would always be further from the ctual contact point in comparison.

For real world tip sizes the effect is not as pronounced of course.

You can test this for yourself using a challenge draw shot, and a striped ball (to see where you really hit the ball, compared to where you thought you hit it).

In general, you hit closer to where you thought you hit with a smaller tip, hence the illusion of more spin. But in reality, you can get just as much spin with a large tip (even over 14 mm!) than with a small tip.

This argument also says that a larger tip is not "more forgiving" than a smaller tip (I believe that this is also a myth) just less accurate.

Tony
-has recently "moved up" to a 12.3 mm tip! (for pool, 10.0 mm for Snooker)

TonyM
04-22-2002, 02:44 PM
"The 12mm requires little or no correction for squirt. The 12/1/2mm requires only slight correction, I believe this is due to it having a pro taper. "

In all likelyhood, the slightly more correction for squirt seen with the larger diameter shaft is probably not due to the taper, but rather the extra diameter and ferrule length. Both will give a little bit more effective endmass, and therefore a bit more squirt.

Tony
-prefers a bit of cone in his shafts...but not because of squirt..

stickman
04-22-2002, 03:39 PM
Thanks, Tony. I'll just stick with saying I like this stick better. /ccboard/images/icons/smile.gif

Alfie
04-22-2002, 05:26 PM
Quote TonyM, Mad Scientist of Cuemaking: "Actually, I don't think that it is neccessarily desirable to have the balance point as far back as possible. The idea with this approach is to have the extra heft in your back hand provide a feedback due to gravity. While this is one way to provide a feedback, it is by no means the only way (or the preferable way imo). The other way is to distribute the weight as far apart as possible (sort of like a bar- bell, or tight-rope walker pole effect).

"This way, the moment of inertia about the bridge hand is maximized. The effect can even be quantified, by assuming a known amount of torque about the bridge hand (due to a stroke error) and comparing various weight distributions and calculating the actual final stroke angular error. Mike Page did this on RSB a few years ago, and the best results (least amount of angular error) were for a weight distribution that employed the balance weights separated by as much distance as possible. This meant that some of the weight was in the very rear of the cue, and some was toward the front (but not so far that it adversely affected squirt!)."


Alright, I'm willing to get off that draw/follow/BP thing.

Here is the original repeat of Mike P's post by Mike P.
<a target="_blank" href=http://groups.google.com/groups?selm=mike_page-2612001027480001%40page.chem.ndsu.nodak.edu>http://groups.google.com/groups?selm=mike_page-2612001027480001%40page.chem.ndsu.nodak.edu</a>

He was talking about maximizing the moment of inertia about the bridge hand.

I get that you get from his post that it is the "barbell shape" of the mass distribution that is the thing increasing the moment of inertia when in fact it is the amount of mass at the butt that does it. The mass at the bridge merely allows the butt mass to be at a maximum. The barbell shape maximizes the moment of inertia about the BP, not about the bridge hand. Now, if we were to allow the BP to move back, we would see a decrease in mass at the bridge and an increase in mass at the butt.

For the same givens as in his example except now a BP of 45" from tip (I know, I know but, for the sake of argument ...), the best mass distribution would be 6 oz at the bridge hand and 14 oz at the butt. This gives an I = 35,000 oz*in**2, greater than in the original example.

This tells me to move the BP back until just before the front end becomes unstable.

IMO

TonyM
04-22-2002, 10:58 PM
Alfie says:

"I get that you get from his post that it is the "barbell shape" of the mass distribution that is the thing increasing the moment of inertia when in fact it is the amount of mass at the butt that does it. The mass at the bridge merely allows the butt mass to be at a maximum. The barbell shape maximizes the moment of inertia about the BP, not about the bridge hand. Now, if we were to allow the BP to move back, we would see a decrease in mass at the bridge and an increase in mass at the butt."

Well I don't quite agree with you here Alfie. If you reread Mike's post, you'll see that if the majority of the weight is moved to the rear (with an equal balance point), the moment of inertia is not maximized. And yes, it is correct to say that the moment of inertia is located about the balance point. So the bar bell mass distribution is still what is creating the highest moment of inertia as far as I'm concerned.

Your example of a much farther rearward balance point does improve the moment of inertia, but with a non practical example! I guess the next question would be, at what point is the tip becoming unstable? For me this implies a set minimum amount of weight at the bridge hand. This might vary from player to player.

To my mind, this is more important than the actual balance point (which is somewhat meaningless without knowing the location of the bp relative to the grip hand imo).

Tony

Alfie
04-23-2002, 02:11 AM
Alf-- I get that you get from his post that it is the "barbell shape" of the mass distribution that is the thing increasing the moment of inertia when in fact it is the amount of mass at the butt that does it. The mass at the bridge merely allows the butt mass to be at a maximum. The barbell shape maximizes the moment of inertia about the BP, not about the bridge hand. Now, if we were to allow the BP to move back, we would see a decrease in mass at the bridge and an increase in mass at the butt.

Tony-- Well I don't quite agree with you here Alfie. If you reread Mike's post, you'll see that if the majority of the weight is moved to the rear (with an equal balance point), the moment of inertia is not maximized.

Alf-- Must be some poor communication somewhere. I've read, understood, and agreed with everything Mike said. If you've done the same then we must be agreeing.

Tony-- And yes, it is correct to say that the moment of inertia is located about the balance point. So the bar bell mass distribution is still what is creating the highest moment of inertia as far as I'm concerned.

Alf-- Well, I don't want to get sidetracked nitpicking this particular point, unless you want to. :-)

Tony-- Your example of a much farther rearward balance point does improve the moment of inertia, but with a non practical example!

Alf-- Umm, Tony, we are talking about an idealized cue of zero density everywhere except at two points. You want practical? I could just as well have said back the BP up 2" instead of 5". The same thing would happen, less mass at the bridge, more mass at the butt, and a greater moment of inertia.

Tony-- I guess the next question would be, at what point is the tip becoming unstable? For me this implies a set minimum amount of weight at the bridge hand. This might vary from player to player.

To my mind, this is more important than the actual balance point (which is somewhat meaningless without knowing the location of the bp relative to the grip hand imo).

Alf-- It is as easy to measure where the BP is relative to the grip hand as it is to measure how much weight is on the front hand, ... perhaps not as accurately. :-)

Given both front and back hand positions (these do vary from player to player, along with the ability to control the front end) and a set cue length and weight, each weight measured on the front hand corresponds to a particular BP, and vice versa. To maximize the moment of inertia about the bridge hand I say bring the BP rearward until just before the front end becomes unstable; you say (that is, I think you do) lighten the weight on the bridge hand until just before the front end becomes unstable. It's the same thing.

Of course, if you are not saying this then you are not trying to maximize the moment of inertia (which is fine by me, btw).

IMO

cheesemouse
04-23-2002, 02:17 AM
You guys have lost it. /ccboard/images/icons/smile.gif /ccboard/images/icons/smile.gif

Alfie
04-23-2002, 03:48 AM
Quote cheesemouse: "You guys have lost it."

Why, CheeseMoose, you've been reading this stuff? hehehe

cheesemouse
04-23-2002, 08:21 AM
Alfie,
LMAO /ccboard/images/icons/smile.gif Hell, some of them I had to read twice.......

Alfie
04-23-2002, 10:12 PM
Tony-- Well I don't quite agree with you here Alf. If you reread Mike's post, you'll see that if the majority of the weight is moved to the rear (with an equal balance point), the moment of inertia is not maximized.

Alf-- I agree that model (d) had the greatest moment of the four models Mike presented.

Tony-- And yes, it is correct to say that the moment of inertia is located about the balance point.

Alf-- Well, I felt the need to make a distinction between the moment about the bridge hand and the moment about the BP. They are two different things.

Tony-- So the bar bell mass distribution is still what is creating the highest moment of inertia as far as I'm concerned.

Alf-- I should have said that though its presence is necessary to maximize I in this example, the mass at the bridge hand does not appear in the calculation for I.