Rail profile

Fuji-whopper

Fargo: 457...play some?
Silver Member
Rail height

While wondering what makes tables play differently from place to place, table to table, the question of rails came into light.

The rails we currently play on have a point on them, smaller/larger balls and incorrect installation may make the point higher or lower the contact point therefore affecting the outcome immensely. So why do rails come to a point?

In the past I have seen rails that are flat in the area where contact is made which was odd when I saw it, being that I was very new to the game and it was the first time I saw something like this. But after thinking about it rails like this might make tables play more consistently regardless of ball size and installation.

Does any agree or disagree to this? I would like to hear both sides and possibly come up with a good solution to this "problem", or am I just nuts and it doesn't matter one bit?
 
Last edited:
faster rails

Neil,

I think you are absolutely right that a wider lip on the rail would make for a more consistent, I think better, playing rail. However the current thing with rails and cloth seems to be that faster is better. The rails that come to a point have more give and more rebound than a flatter faced rail and play faster made with the same material. A wider face would be more consistent and less critical of minor installation errors or variances in balls.

I don't know if you have played on deep cloth and slow rails but it becomes a vastly different and considerably tougher game. Many of the finesse players of today would have much more of an issue with their strokes if they had to hit every shot involving rails 30%-50% harder which is just my guess as to how much difference slow rails would make. My game actually jumps a ball or two when I get on a table with slow rails, that is what I cut my teeth on. I wish they would come back in style. The good players would rapidly adjust, the weaker players would have more trouble.

It seems that most "improvements" in pool focus on narrowing the gap between the weaker and stronger players. Faster rails and cloth, smaller tables, jump cues, break cues, phenolic and layered tips, all of these things bring playing levels closer together. The better players still win but the weaker players feel much more that they are in the game.

Hu

While wondering what makes tables play differently from place to place, table to table, the question of rails came into light.

The rails we currently play on have a point on them, smaller/larger balls and incorrect installation may make the point higher or lower the contact point therefore affecting the outcome immensely. So why do rails come to a point?

In the past I have seen rails that are flat in the area where contact is made which was odd when I saw it, being that I was very new to the game and it was the first time I saw something like this. But after thinking about it rails like this might make tables play more consistently regardless of ball size and installation.

Does any agree or disagree to this? I would like to hear both sides and possibly come up with a good solution to this "problem", or am I just nuts and it doesn't matter one bit?
 
wouldn's a flat faced rail effect the spin that a ball has coming off of the rail?
 
While wondering what makes tables play differently from place to place, table to table, the question of rails came into light.

The rails we currently play on have a point on them, smaller/larger balls and incorrect installation may make the point higher or lower the contact point therefore affecting the outcome immensely. So why do rails come to a point?

In the past I have seen rails that are flat in the area where contact is made which was odd when I saw it, being that I was very new to the game and it was the first time I saw something like this. But after thinking about it rails like this might make tables play more consistently regardless of ball size and installation.

Does any agree or disagree to this? I would like to hear both sides and possibly come up with a good solution to this "problem", or am I just nuts and it doesn't matter one bit?

The pool table rails are actually radiused. To what angle I have no clue. Those flat ones you are talking about, I used to see on Snooker tables.

The rail profile, composition, and height have everything to do with how the ball reacts off the rail.

Beats me what is more consistent/better.

For shi*s and giggle's, I think the radiused (point) ones would be more consistent. Less area of friction or wrap-around. For some reason it makes sense in my head.
 
...The rails we currently play on have a point on them, smaller/larger balls and incorrect installation may make the point higher or lower the contact point therefore affecting the outcome immensely. So why do rails come to a point?

In the past I have seen rails that are flat in the area where contact is made which was odd when I saw it, being that I was very new to the game and it was the first time I saw something like this. But after thinking about it rails like this might make tables play more consistently regardless of ball size and installation.
The rules specify that the nose ("point") of the cushion is 63.5% +/- 1% of a ball's diameter above the bed. Cushion dynamics are complicated, but this means, at least approximately, that the spring (compression) force points downward through the center of a ball at about 16 degrees from horizontal. This prevents a ball with topspin from climbing up the cushion due to ball/cloth friction. To the extent that this downward angle is maintained as the cushion compresses, it can prevent a ball with topspin from climbing for coefficients of friction anywhere up to about .27. Typical values are 0.20. There may be other reasons which I'm unaware of.

As currently designed, the rebound angle is almost completely independent of ball speed, as long as the spin on a ball doesn't change enroute to the cushion (i.e., gains a topspin component). Bob Jewett demonstrates this here:

http://billiards.colostate.edu/high_speed_videos/new/HSVB-41.htm

I don't see flat faced cushions being an improvement, particularly with the climbing issue, but I can't say I know much about it.

Jim
 
The rules specify that the nose ("point") of the cushion is 63.5% +/- 1% of a ball's diameter above the bed. Cushion dynamics are complicated, but this means, at least approximately, that the spring (compression) force points downward through the center of a ball at about 16 degrees from horizontal. This prevents a ball with topspin from climbing up the cushion due to ball/cloth friction. To the extent that this downward angle is maintained as the cushion compresses, it can prevent a ball with topspin from climbing for coefficients of friction anywhere up to about .27. Typical values are 0.20. There may be other reasons which I'm unaware of.

As currently designed, the rebound angle is almost completely independent of ball speed, as long as the spin on a ball doesn't change enroute to the cushion (i.e., gains a topspin component). Bob Jewett demonstrates this here:

http://billiards.colostate.edu/high_speed_videos/new/HSVB-41.htm

I don't see flat faced cushions being an improvement, particularly with the climbing issue, but I can't say I know much about it.

Jim

I actually understood that. :D
 
Rail profile: There's Arthur, Robert, and Clyde, who are all retired but their wives kick them all out of their houses till dinner time. Arthur's the leader since Robert and Clyde don't really like each other that much. And there's Jack, who now is much better at thinking and knowing pool than doing it. This makes him angry so he soothes his irritation by putting everyone else down. Then there's Mark. We don't actually know too much about him personally, where he got or gets his money, but he's side- splittingly funny and always in a good mood. And there's Carter. He seems nice enough and is ALWAYS there, but he doesn't actually talk to anyone very often.*

oh wait. table rails. I got you. : )

(thanks for the link- the video of the cb moving down the rail before bouncing off was very different from what I expected to see.)


*names and stories are representative only and are not intended to describe ayone in particular.
 
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