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#51
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Tire-making: bead stress, tire width, math, woe........
On Wed, 24 Aug 2011 05:33:41 -0700 (PDT), DirtRoadie
wrote: On Aug 24, 5:32*am, john B. wrote: On Tue, 23 Aug 2011 17:09:41 -0700 (PDT), DirtRoadie wrote: On Aug 23, 5:42 pm, john B. wrote: On Tue, 23 Aug 2011 06:32:23 -0700 (PDT), DirtRoadie wrote: On Aug 23, 6:02 am, john B. wrote: On Mon, 22 Aug 2011 19:55:32 -0700 (PDT), DirtRoadie wrote: On Aug 22, 7:37 pm, john B. wrote: On Mon, 22 Aug 2011 13:32:01 -0700 (PDT), thirty-six wrote: On Aug 22, 9:28 pm, DougC wrote: On 8/22/2011 1:18 PM, thirty-six wrote: The wire stiffens the connection with the rim so that the tyre stays in place. The wire's strength is of no particular importance, it's the resistance to bending which is key. ... I don't know if I believe that. It would mean that you could take a clincher tire and cut both beads completely through--and then mount & inflate it and still have it stay on the rim, with just as much pressure as with the beads uncut. You would be breaking the beam and so the hold of the tyre is compromised around the cut. Test it statically. Do not ride it at speed. Obviously the beads are placed under great tension in use, since for ~100 years steel was the only material used and in the last several decades the only other material used has been kevlar (which is also a high tensile strength material). The steel wire is used as a beam for the tyre's unfortunate edge. The tubular tyre does not of course suffer from this liability as the edges are joined together making the tyre essentially edgeless. Errr... there is no "beam" involved in tire strength. The bead reinforcement - i.e., the steel or kevlar cable in this case - is stressed longitudinally, in reference to the cable, as it is used to prevent the bead stretching. Everyone seems to want to fully adopt one side or the other in this "belt v. suspenders" discussion. There should really no problem accepting that there are two mechanism that can work and they can (and undoubtedly do) work together. With NO "hook" at the bead, the bead reinforcement does have to take on the full responsibility for constraining the forces of air pressure (and all others) within the tire. But add a substantial hook and the job of the bead reinforcement becomes much easier. With a suitable means of securing the tire edge to the rim (thinking hypothetically) all the way around, the longitudinal strength/stretch resistance of the bead reinforcement becomes less important or even unnecessary. Kevlar, by the way, is used because it doesn't stretch, not primarily because it is a high strength material. And very UN-stretchy carbon is also becoming the material of choice. DR The whole discussion seems centered on a bicycle wheel, as though nothing else used rubber wheel covers :-) More to the point a day or so ago I walked by a tire and hose dealer who supplied the aircraft. In his front window he had an aircraft tire - About 5 ft. in diameter - and beside it a section cut from the tire. the bead reinforcing cable was slightly over 1 inch in diameter. I wonder what all of those reinforced tire beads are doing out there if they aren't required. Must be a lot of really stupid tire makers. Sounds like you are a "belt" kinda' guy and gotta' have it - with or without suspenders. Yes, we were talking about bicycle wheels which, at present, most commonly have BOTH a tire with your precious bead reinforcement material AND a rim with a bead engaging "hook." Does the aircraft tire you saw have a hooked bead interface? As a more common comparison, automobile tires do not. See example: http://www.offroaders.com/tech/AT-MT...t-cross-sectio... So it is of little surprise that they must have a strong bead reinforcement and has little to do with whether the manufacturers are smart or stupid. But that hardly establishes that such a bead reinforcement is absolutely necessary where there IS a sufficient mechanical (i.e. hooked or even interlocked) bead interface. See: http://bit.ly/nA53me Belt and/or suspenders, right? DR I think that the most powerful rebuttal to your point is that a tire built without any form of bead reinforcement would be substantially lighter then a tire built with one and as we all know light is wonderful in the bicycle world. Oh? Then let's get right to it. But don't forget that we still need some way to fully secure the constrain the tire bead radially to the rim. You have obviously conceived of a way to do that which involves no weight whatsoever. Please share. Get right to it? I'm merely responding you your statement "But that hardly establishes that such a bead reinforcement is absolutely necessary where there IS a sufficient mechanical (i.e. hooked or even interlocked) bead interface." I'm not even contesting your remark. I'm only saying that nobody is building such tires... Even though they would be substantially lighter and would sell faster then you could get them out of the mold. I wonder why? They do not exist yet you KNOW they would be lighter. A silly proposition. So you say.... Of course, if you remove some 160 inches of steel cable it will make things heavier. After all, several folks have "proved" that it is unnecessary by mounting tires with said cable cut. If we eliminate a belt by substituting suspenders, we lose the weight of the belt. But that does not insure that the suspenders system is overall, lighter. We have, after all, added suspenders. No, it is alleged that neither the belt nor the suspenders are required 'cause they cut the belt in a suspender-less tire and inflating it. Guy said so right here. Since we are talking about tires I will note that the same error in logic is presently made with regard to tubeless bicycle tires. "Common knowledge" often suggests that a tubeless system is inherently lighter since it eliminates the weight of a tube. However this conveniently ignores that system weight is also typically added in the form of extra material in the tire, a heavier rim strip and/or added liquid sealant. DR Ah Ha... remove the steel wire and replace it with something else..... But I read right here that by cutting the bead and inflating a tire it was proved that the bead don't do nuttin. Now you are saying it does?????? As I said, WHY are those idiots that make their living building tires using this archaic (and heavy) system - must be pretty dumb. Cheers, John B. |
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#52
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Tire-making: bead stress, tire width, math, woe........
On Aug 24, 5:28*pm, john B. wrote:
On Wed, 24 Aug 2011 05:33:41 -0700 (PDT), DirtRoadie wrote: On Aug 24, 5:32 am, john B. wrote: On Tue, 23 Aug 2011 17:09:41 -0700 (PDT), DirtRoadie wrote: On Aug 23, 5:42 pm, john B. wrote: On Tue, 23 Aug 2011 06:32:23 -0700 (PDT), DirtRoadie wrote: On Aug 23, 6:02 am, john B. wrote: On Mon, 22 Aug 2011 19:55:32 -0700 (PDT), DirtRoadie wrote: On Aug 22, 7:37 pm, john B. wrote: On Mon, 22 Aug 2011 13:32:01 -0700 (PDT), thirty-six wrote: On Aug 22, 9:28 pm, DougC wrote: On 8/22/2011 1:18 PM, thirty-six wrote: The wire stiffens the connection with the rim so that the tyre stays in place. The wire's strength is of no particular importance, it's the resistance to bending which is key. ... I don't know if I believe that. It would mean that you could take a clincher tire and cut both beads completely through--and then mount & inflate it and still have it stay on the rim, with just as much pressure as with the beads uncut. You would be breaking the beam and so the hold of the tyre is compromised around the cut. Test it statically. Do not ride it at speed. Obviously the beads are placed under great tension in use, since for ~100 years steel was the only material used and in the last several decades the only other material used has been kevlar (which is also a high tensile strength material). The steel wire is used as a beam for the tyre's unfortunate edge. The tubular tyre does not of course suffer from this liability as the edges are joined together making the tyre essentially edgeless. Errr... there is no "beam" involved in tire strength. The bead reinforcement - i.e., the steel or kevlar cable in this case - is stressed longitudinally, in reference to the cable, as it is used to prevent the bead stretching. Everyone seems to want to fully adopt one side or the other in this "belt v. suspenders" discussion. There should really no problem accepting that there are two mechanism that can work and they can (and undoubtedly do) work together. With NO "hook" at the bead, the bead reinforcement does have to take on the full responsibility for constraining the forces of air pressure (and all others) within the tire. But add a substantial hook and the job of the bead reinforcement becomes much easier. With a suitable means of securing the tire edge to the rim (thinking hypothetically) all the way around, the longitudinal strength/stretch resistance of the bead reinforcement becomes less important or even unnecessary. Kevlar, by the way, is used because it doesn't stretch, not primarily because it is a high strength material. And very UN-stretchy carbon is also becoming the material of choice. DR The whole discussion seems centered on a bicycle wheel, as though nothing else used rubber wheel covers :-) More to the point a day or so ago I walked by a tire and hose dealer who supplied the aircraft. In his front window he had an aircraft tire - About 5 ft. in diameter - and beside it a section cut from the tire. the bead reinforcing cable was slightly over 1 inch in diameter. I wonder what all of those reinforced tire beads are doing out there if they aren't required. Must be a lot of really stupid tire makers. Sounds like you are a "belt" kinda' guy and gotta' have it - with or without suspenders. Yes, we were talking about bicycle wheels which, at present, most commonly have BOTH a tire with your precious bead reinforcement material AND a rim with a bead engaging "hook." Does the aircraft tire you saw have a hooked bead interface? As a more common comparison, automobile tires do not. See example: http://www.offroaders.com/tech/AT-MT...t-cross-sectio... So it is of little surprise that they must have a strong bead reinforcement and has little to do with whether the manufacturers are smart or stupid. But that hardly establishes that such a bead reinforcement is absolutely necessary where there IS a sufficient mechanical (i.e. hooked or even interlocked) bead interface. See: http://bit.ly/nA53me Belt and/or suspenders, right? DR I think that the most powerful rebuttal to your point is that a tire built without any form of bead reinforcement would be substantially lighter then a tire built with one and as we all know light is wonderful in the bicycle world. Oh? Then let's get right to it. But don't forget that we still need some way to fully secure the constrain the tire bead radially to the rim. You have obviously conceived of a way to do that which involves no weight whatsoever. Please share. Get right to it? I'm merely responding you your statement "But that hardly establishes that such a bead reinforcement is absolutely necessary where there IS a sufficient mechanical (i.e. hooked or even interlocked) bead interface." I'm not even contesting your remark. I'm only saying that nobody is building such tires... Even though they would be substantially lighter and would sell faster then you could get them out of the mold. I wonder why? They do not exist yet you KNOW they would be lighter. A silly proposition. So you say.... Of course, if you remove some 160 inches of steel cable it will make things heavier. After all, several folks have "proved" that it is unnecessary by mounting tires with said cable cut. If we eliminate a belt by substituting suspenders, we lose the weight of the belt. But that does not insure that the suspenders system is overall, lighter. *We have, after all, added suspenders. No, it is alleged that neither the belt nor the suspenders are required 'cause they cut the belt in a suspender-less tire and inflating it. Guy said so right here. Interesting interpretation. You are struggling to justify your nonsensical position. "They" cut the tire bead ("belt") on a rim with a hooked bead ("suspenders") I have no idea how you reached your conclusion. Since we are talking about tires I will note that the same error in logic is presently made *with regard to tubeless *bicycle tires. "Common knowledge" often suggests that a tubeless system is inherently lighter since it eliminates the weight of a tube. However this conveniently ignores that system weight is also typically added in the form of extra material in the tire, a heavier rim strip and/or added liquid sealant. Ah Ha... remove the steel wire and replace it with something else..... But I read right here that by cutting the bead and inflating a tire it was proved that the bead don't do nuttin. Now you are saying it does?????? Again, your interpretation. I have never suggested that, under all circumstances. the tire bead reinforcement does nothing Quite the contrary. Indeed, if the tire bead is the "belt" and there are no "suspenders," it is critical. Example: automotive tubeless tire. But if there are "suspenders" (hooked rim) it is not so critical. Please don't try to put words in my mouth based upon what you wish I had said. Now if you are merely criticizing words used by someone else in the cut bead experiment I may tend to agree with you. This is not a black'white - either/or situtation. As I said, WHY are those idiots that make their living building tires using this archaic (and heavy) system - must be pretty dumb. Could be. Seems to more or less work. That does not exclude other possibilities, maybe even improvements. In fact, I have read that while tubeless "conversions" (making a non- tubeless rim and tire into a tubeless setup) are common (or "trendy") for MTB use, the same is not recommended for road tires because of the high probability of the tire blowing off if the rim/tire combo is not designed for tubeless use. And "designed for tubeless use" seems to involves changes in both the rim/tire interface AND the tire bead itself (that's where carbon seems to be appearing). Geeze, you aren't one of those "It's alway been like this so it can't be improved" idiots, are you? And, please, don't provide examples of things that have been tried which did not work. There are plenty. They merely provide support for not being an early adopter. If you want to avoid thinking about changes/improvements you can go back to your "ordinary." For that matter you can go back to whatever there was before someone came up with what we now know as a "wheel." DR |
#53
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Tire-making: bead wire, shiny and otherwise
On 8/24/2011 4:38 PM, AMuzi wrote:
DougC wrote: On 8/22/2011 11:47 AM, DougC wrote: ......... Also note: I already know that tire beads aren't usually made of stainless wire, but I can't get the same stuff the big companies all use and plain chrome steel would rust too easily. The "real" stuff is bronze-plated chrome steel spring wire, but the only purpose of it seems to be for tire beads, and I haven't found anyone selling small quantities of it that isn't already made into tires. I don't know, but what do pianos use for wire? You aren't making a thousand pieces; something like that which is readily available may be a plus. I already said what normal tires (car, motorcycle and bicycle at least) use. The "real" stuff is (deep breath) bronze-plated chrome-steel spring-tempered wire. Music wire is all that BUT bronze-plated, it's not greatly expensive and ordinary mortals can buy 1 - 5 - 10 lb spools of it, but bronze-plating it myself is not economically viable. The bronze plating serves to increase the rubber's ability to bond to the cable, by inhibiting rust. As the rubber cures it gives off water, and plain carbon-steel wire would quickly begin to corrode in such circumstances. On the grand scales of industrial purchasing, bronze-plated carbon-steel spring-temper wire is cheaper than stainless--but not on mine. So I don't really have a choice there--but there's no evidence that the stainless is lacking in any regard; much of the lifting wire rope and cable in use for everything else is stainless anyway (-such as,,, bike shifter and brake cables, for example...). |
#54
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Tire-making: bead wire, shiny and otherwise
On Aug 24, 6:53*pm, DougC wrote:
On 8/24/2011 4:38 PM, AMuzi wrote: DougC wrote: On 8/22/2011 11:47 AM, DougC wrote: ......... Also note: I already know that tire beads aren't usually made of stainless wire, but I can't get the same stuff the big companies all use and plain chrome steel would rust too easily. The "real" stuff is bronze-plated chrome steel spring wire, but the only purpose of it seems to be for tire beads, and I haven't found anyone selling small quantities of it that isn't already made into tires. I don't know, but what do pianos use for wire? You aren't making a thousand pieces; something like that which is readily available may be a plus. I already said what normal tires (car, motorcycle and bicycle at least) use. The "real" stuff is (deep breath) bronze-plated chrome-steel spring-tempered wire. Music wire is all that BUT bronze-plated, it's not greatly expensive and ordinary mortals can buy 1 - 5 - 10 lb spools of it, but bronze-plating it myself is not economically viable. The bronze plating serves to increase the rubber's ability to bond to the cable, by inhibiting rust. As the rubber cures it gives off water, and plain carbon-steel wire would quickly begin to corrode in such circumstances. On the grand scales of industrial purchasing, bronze-plated carbon-steel spring-temper wire is cheaper than stainless--but not on mine. So I don't really have a choice there--but there's no evidence that the stainless is lacking in any regard; much of the lifting wire rope and cable in use for everything else is stainless anyway (-such as,,, bike shifter and brake cables, for example...). OK, at the risk of opening a huge can of worms.... Are you (we) only considering some sort of metallic bead reinforcement? As opposed to the well known exotic synthetics used for the purpose. Just asking. I think you described your project at some point but I do not recall details. You have both my respect and disdain (if you know what I mean). DR |
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Tire-making: bead stress, tire width, math, woe........
On Aug 24, 5:28*pm, john B. wrote:
On Wed, 24 Aug 2011 05:33:41 -0700 (PDT), DirtRoadie wrote: On Aug 24, 5:32 am, john B. wrote: On Tue, 23 Aug 2011 17:09:41 -0700 (PDT), DirtRoadie wrote: On Aug 23, 5:42 pm, john B. wrote: On Tue, 23 Aug 2011 06:32:23 -0700 (PDT), DirtRoadie wrote: On Aug 23, 6:02 am, john B. wrote: On Mon, 22 Aug 2011 19:55:32 -0700 (PDT), DirtRoadie wrote: On Aug 22, 7:37 pm, john B. wrote: On Mon, 22 Aug 2011 13:32:01 -0700 (PDT), thirty-six wrote: On Aug 22, 9:28 pm, DougC wrote: On 8/22/2011 1:18 PM, thirty-six wrote: The wire stiffens the connection with the rim so that the tyre stays in place. The wire's strength is of no particular importance, it's the resistance to bending which is key. ... I don't know if I believe that. It would mean that you could take a clincher tire and cut both beads completely through--and then mount & inflate it and still have it stay on the rim, with just as much pressure as with the beads uncut. You would be breaking the beam and so the hold of the tyre is compromised around the cut. Test it statically. Do not ride it at speed. Obviously the beads are placed under great tension in use, since for ~100 years steel was the only material used and in the last several decades the only other material used has been kevlar (which is also a high tensile strength material). The steel wire is used as a beam for the tyre's unfortunate edge. The tubular tyre does not of course suffer from this liability as the edges are joined together making the tyre essentially edgeless. Errr... there is no "beam" involved in tire strength. The bead reinforcement - i.e., the steel or kevlar cable in this case - is stressed longitudinally, in reference to the cable, as it is used to prevent the bead stretching. Everyone seems to want to fully adopt one side or the other in this "belt v. suspenders" discussion. There should really no problem accepting that there are two mechanism that can work and they can (and undoubtedly do) work together. With NO "hook" at the bead, the bead reinforcement does have to take on the full responsibility for constraining the forces of air pressure (and all others) within the tire. But add a substantial hook and the job of the bead reinforcement becomes much easier. With a suitable means of securing the tire edge to the rim (thinking hypothetically) all the way around, the longitudinal strength/stretch resistance of the bead reinforcement becomes less important or even unnecessary. Kevlar, by the way, is used because it doesn't stretch, not primarily because it is a high strength material. And very UN-stretchy carbon is also becoming the material of choice. DR The whole discussion seems centered on a bicycle wheel, as though nothing else used rubber wheel covers :-) More to the point a day or so ago I walked by a tire and hose dealer who supplied the aircraft. In his front window he had an aircraft tire - About 5 ft. in diameter - and beside it a section cut from the tire. the bead reinforcing cable was slightly over 1 inch in diameter. I wonder what all of those reinforced tire beads are doing out there if they aren't required. Must be a lot of really stupid tire makers. Sounds like you are a "belt" kinda' guy and gotta' have it - with or without suspenders. Yes, we were talking about bicycle wheels which, at present, most commonly have BOTH a tire with your precious bead reinforcement material AND a rim with a bead engaging "hook." Does the aircraft tire you saw have a hooked bead interface? As a more common comparison, automobile tires do not. See example: http://www.offroaders.com/tech/AT-MT...t-cross-sectio... So it is of little surprise that they must have a strong bead reinforcement and has little to do with whether the manufacturers are smart or stupid. But that hardly establishes that such a bead reinforcement is absolutely necessary where there IS a sufficient mechanical (i.e. hooked or even interlocked) bead interface. See: http://bit.ly/nA53me Belt and/or suspenders, right? DR I think that the most powerful rebuttal to your point is that a tire built without any form of bead reinforcement would be substantially lighter then a tire built with one and as we all know light is wonderful in the bicycle world. Oh? Then let's get right to it. But don't forget that we still need some way to fully secure the constrain the tire bead radially to the rim. You have obviously conceived of a way to do that which involves no weight whatsoever. Please share. Get right to it? I'm merely responding you your statement "But that hardly establishes that such a bead reinforcement is absolutely necessary where there IS a sufficient mechanical (i.e. hooked or even interlocked) bead interface." I'm not even contesting your remark. I'm only saying that nobody is building such tires... Even though they would be substantially lighter and would sell faster then you could get them out of the mold. I wonder why? They do not exist yet you KNOW they would be lighter. A silly proposition. So you say.... Of course, if you remove some 160 inches of steel cable it will make things heavier. After all, several folks have "proved" that it is unnecessary by mounting tires with said cable cut. Oops, missed this. Do us all a favor and see if you can maintain consistency in the points you present. You assumed "removal of bead reinforcement" (with no suggestion of structure to replace its function) and asserted "lighter" which is not a reasonable assumption. Maybe it could be done, maybe it couldn't but your unsupported assumption cannot be allowed to stand. Now you are also suggesting "cut." Sorry dude, cut is neither "removed" nor "lighter." DR |
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Tire-making: bead wire, shiny and otherwise
-snip tire bead-
DirtRoadie wrote: You have both my respect and disdain (if you know what I mean). Now that's creative writing! -- Andrew Muzi www.yellowjersey.org/ Open every day since 1 April, 1971 |
#57
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Tire-making: bead wire, shiny and otherwise
On Aug 24, 9:15*pm, AMuzi wrote:
-snip tire bead- DirtRoadie wrote: You have both my respect and *disdain (if you know what I mean). Now that's creative writing! Lemme 'splain. Respect: It's interesting that someone would take the time necessary to learn how to accomplish all the details required to assemble a bicycle tire starting tire from scratch. Disdain: Why would anyone waste the time trying to reproduce from scratch an item that is readily available commercially? DR |
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Tire-making: bead wire, shiny and otherwise
On 8/24/2011 11:24 PM, DirtRoadie wrote:
On Aug 24, 9:15 pm, wrote: -snip tire bead- DirtRoadie wrote: You have both my respect and disdain (if you know what I mean). Now that's creative writing! Lemme 'splain. Respect: It's interesting that someone would take the time necessary to learn how to accomplish all the details required to assemble a bicycle tire starting tire from scratch. Disdain: Why would anyone waste the time trying to reproduce from scratch an item that is readily available commercially? DR The big factories are limited in what they can offer, by what is possible on the mass-production equipment they have. I want tires that the big factories don't make. And I'm betting that lots of other people do, too. |
#59
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Tire-making: bead stress, tire width, math, woe........
On Wed, 24 Aug 2011 17:50:19 -0700 (PDT), DirtRoadie
wrote: On Aug 24, 5:28*pm, john B. wrote: On Wed, 24 Aug 2011 05:33:41 -0700 (PDT), DirtRoadie wrote: On Aug 24, 5:32 am, john B. wrote: On Tue, 23 Aug 2011 17:09:41 -0700 (PDT), DirtRoadie wrote: On Aug 23, 5:42 pm, john B. wrote: On Tue, 23 Aug 2011 06:32:23 -0700 (PDT), DirtRoadie wrote: On Aug 23, 6:02 am, john B. wrote: On Mon, 22 Aug 2011 19:55:32 -0700 (PDT), DirtRoadie wrote: On Aug 22, 7:37 pm, john B. wrote: On Mon, 22 Aug 2011 13:32:01 -0700 (PDT), thirty-six wrote: On Aug 22, 9:28 pm, DougC wrote: On 8/22/2011 1:18 PM, thirty-six wrote: The wire stiffens the connection with the rim so that the tyre stays in place. The wire's strength is of no particular importance, it's the resistance to bending which is key. ... I don't know if I believe that. It would mean that you could take a clincher tire and cut both beads completely through--and then mount & inflate it and still have it stay on the rim, with just as much pressure as with the beads uncut. You would be breaking the beam and so the hold of the tyre is compromised around the cut. Test it statically. Do not ride it at speed. Obviously the beads are placed under great tension in use, since for ~100 years steel was the only material used and in the last several decades the only other material used has been kevlar (which is also a high tensile strength material). The steel wire is used as a beam for the tyre's unfortunate edge. The tubular tyre does not of course suffer from this liability as the edges are joined together making the tyre essentially edgeless. Errr... there is no "beam" involved in tire strength. The bead reinforcement - i.e., the steel or kevlar cable in this case - is stressed longitudinally, in reference to the cable, as it is used to prevent the bead stretching. Everyone seems to want to fully adopt one side or the other in this "belt v. suspenders" discussion. There should really no problem accepting that there are two mechanism that can work and they can (and undoubtedly do) work together. With NO "hook" at the bead, the bead reinforcement does have to take on the full responsibility for constraining the forces of air pressure (and all others) within the tire. But add a substantial hook and the job of the bead reinforcement becomes much easier. With a suitable means of securing the tire edge to the rim (thinking hypothetically) all the way around, the longitudinal strength/stretch resistance of the bead reinforcement becomes less important or even unnecessary. Kevlar, by the way, is used because it doesn't stretch, not primarily because it is a high strength material. And very UN-stretchy carbon is also becoming the material of choice. DR The whole discussion seems centered on a bicycle wheel, as though nothing else used rubber wheel covers :-) More to the point a day or so ago I walked by a tire and hose dealer who supplied the aircraft. In his front window he had an aircraft tire - About 5 ft. in diameter - and beside it a section cut from the tire. the bead reinforcing cable was slightly over 1 inch in diameter. I wonder what all of those reinforced tire beads are doing out there if they aren't required. Must be a lot of really stupid tire makers. Sounds like you are a "belt" kinda' guy and gotta' have it - with or without suspenders. Yes, we were talking about bicycle wheels which, at present, most commonly have BOTH a tire with your precious bead reinforcement material AND a rim with a bead engaging "hook." Does the aircraft tire you saw have a hooked bead interface? As a more common comparison, automobile tires do not. See example: http://www.offroaders.com/tech/AT-MT...t-cross-sectio... So it is of little surprise that they must have a strong bead reinforcement and has little to do with whether the manufacturers are smart or stupid. But that hardly establishes that such a bead reinforcement is absolutely necessary where there IS a sufficient mechanical (i.e. hooked or even interlocked) bead interface. See: http://bit.ly/nA53me Belt and/or suspenders, right? DR I think that the most powerful rebuttal to your point is that a tire built without any form of bead reinforcement would be substantially lighter then a tire built with one and as we all know light is wonderful in the bicycle world. Oh? Then let's get right to it. But don't forget that we still need some way to fully secure the constrain the tire bead radially to the rim. You have obviously conceived of a way to do that which involves no weight whatsoever. Please share. Get right to it? I'm merely responding you your statement "But that hardly establishes that such a bead reinforcement is absolutely necessary where there IS a sufficient mechanical (i.e. hooked or even interlocked) bead interface." I'm not even contesting your remark. I'm only saying that nobody is building such tires... Even though they would be substantially lighter and would sell faster then you could get them out of the mold. I wonder why? They do not exist yet you KNOW they would be lighter. A silly proposition. So you say.... Of course, if you remove some 160 inches of steel cable it will make things heavier. After all, several folks have "proved" that it is unnecessary by mounting tires with said cable cut. If we eliminate a belt by substituting suspenders, we lose the weight of the belt. But that does not insure that the suspenders system is overall, lighter. *We have, after all, added suspenders. No, it is alleged that neither the belt nor the suspenders are required 'cause they cut the belt in a suspender-less tire and inflating it. Guy said so right here. Interesting interpretation. You are struggling to justify your nonsensical position. "They" cut the tire bead ("belt") on a rim with a hooked bead ("suspenders") I have no idea how you reached your conclusion. Since we are talking about tires I will note that the same error in logic is presently made *with regard to tubeless *bicycle tires. "Common knowledge" often suggests that a tubeless system is inherently lighter since it eliminates the weight of a tube. However this conveniently ignores that system weight is also typically added in the form of extra material in the tire, a heavier rim strip and/or added liquid sealant. Ah Ha... remove the steel wire and replace it with something else..... But I read right here that by cutting the bead and inflating a tire it was proved that the bead don't do nuttin. Now you are saying it does?????? Again, your interpretation. I have never suggested that, under all circumstances. the tire bead reinforcement does nothing Quite the contrary. Indeed, if the tire bead is the "belt" and there are no "suspenders," it is critical. Example: automotive tubeless tire. But if there are "suspenders" (hooked rim) it is not so critical. Please don't try to put words in my mouth based upon what you wish I had said. Now if you are merely criticizing words used by someone else in the cut bead experiment I may tend to agree with you. This is not a black'white - either/or situtation. As I said, WHY are those idiots that make their living building tires using this archaic (and heavy) system - must be pretty dumb. Could be. Seems to more or less work. That does not exclude other possibilities, maybe even improvements. In fact, I have read that while tubeless "conversions" (making a non- tubeless rim and tire into a tubeless setup) are common (or "trendy") for MTB use, the same is not recommended for road tires because of the high probability of the tire blowing off if the rim/tire combo is not designed for tubeless use. And "designed for tubeless use" seems to involves changes in both the rim/tire interface AND the tire bead itself (that's where carbon seems to be appearing). Geeze, you aren't one of those "It's alway been like this so it can't be improved" idiots, are you? And, please, don't provide examples of things that have been tried which did not work. There are plenty. They merely provide support for not being an early adopter. If you want to avoid thinking about changes/improvements you can go back to your "ordinary." For that matter you can go back to whatever there was before someone came up with what we now know as a "wheel." DR Nope. But I do consider myself a competent engineer and one thing you learn early on is to research before you design and if nobody else is considering a new method that you feel you have discovered then perhaps you need to take a second look at things. There may be a reason that nobody else is doing it. Cheers, John B. |
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Tire-making: bead stress, tire width, math, woe........
On Wed, 24 Aug 2011 18:15:50 -0700 (PDT), DirtRoadie
wrote: On Aug 24, 5:28*pm, john B. wrote: On Wed, 24 Aug 2011 05:33:41 -0700 (PDT), DirtRoadie wrote: On Aug 24, 5:32 am, john B. wrote: On Tue, 23 Aug 2011 17:09:41 -0700 (PDT), DirtRoadie wrote: On Aug 23, 5:42 pm, john B. wrote: On Tue, 23 Aug 2011 06:32:23 -0700 (PDT), DirtRoadie wrote: On Aug 23, 6:02 am, john B. wrote: On Mon, 22 Aug 2011 19:55:32 -0700 (PDT), DirtRoadie wrote: On Aug 22, 7:37 pm, john B. wrote: On Mon, 22 Aug 2011 13:32:01 -0700 (PDT), thirty-six wrote: On Aug 22, 9:28 pm, DougC wrote: On 8/22/2011 1:18 PM, thirty-six wrote: The wire stiffens the connection with the rim so that the tyre stays in place. The wire's strength is of no particular importance, it's the resistance to bending which is key. ... I don't know if I believe that. It would mean that you could take a clincher tire and cut both beads completely through--and then mount & inflate it and still have it stay on the rim, with just as much pressure as with the beads uncut. You would be breaking the beam and so the hold of the tyre is compromised around the cut. Test it statically. Do not ride it at speed. Obviously the beads are placed under great tension in use, since for ~100 years steel was the only material used and in the last several decades the only other material used has been kevlar (which is also a high tensile strength material). The steel wire is used as a beam for the tyre's unfortunate edge. The tubular tyre does not of course suffer from this liability as the edges are joined together making the tyre essentially edgeless. Errr... there is no "beam" involved in tire strength. The bead reinforcement - i.e., the steel or kevlar cable in this case - is stressed longitudinally, in reference to the cable, as it is used to prevent the bead stretching. Everyone seems to want to fully adopt one side or the other in this "belt v. suspenders" discussion. There should really no problem accepting that there are two mechanism that can work and they can (and undoubtedly do) work together. With NO "hook" at the bead, the bead reinforcement does have to take on the full responsibility for constraining the forces of air pressure (and all others) within the tire. But add a substantial hook and the job of the bead reinforcement becomes much easier. With a suitable means of securing the tire edge to the rim (thinking hypothetically) all the way around, the longitudinal strength/stretch resistance of the bead reinforcement becomes less important or even unnecessary. Kevlar, by the way, is used because it doesn't stretch, not primarily because it is a high strength material. And very UN-stretchy carbon is also becoming the material of choice. DR The whole discussion seems centered on a bicycle wheel, as though nothing else used rubber wheel covers :-) More to the point a day or so ago I walked by a tire and hose dealer who supplied the aircraft. In his front window he had an aircraft tire - About 5 ft. in diameter - and beside it a section cut from the tire. the bead reinforcing cable was slightly over 1 inch in diameter. I wonder what all of those reinforced tire beads are doing out there if they aren't required. Must be a lot of really stupid tire makers. Sounds like you are a "belt" kinda' guy and gotta' have it - with or without suspenders. Yes, we were talking about bicycle wheels which, at present, most commonly have BOTH a tire with your precious bead reinforcement material AND a rim with a bead engaging "hook." Does the aircraft tire you saw have a hooked bead interface? As a more common comparison, automobile tires do not. See example: http://www.offroaders.com/tech/AT-MT...t-cross-sectio... So it is of little surprise that they must have a strong bead reinforcement and has little to do with whether the manufacturers are smart or stupid. But that hardly establishes that such a bead reinforcement is absolutely necessary where there IS a sufficient mechanical (i.e. hooked or even interlocked) bead interface. See: http://bit.ly/nA53me Belt and/or suspenders, right? DR I think that the most powerful rebuttal to your point is that a tire built without any form of bead reinforcement would be substantially lighter then a tire built with one and as we all know light is wonderful in the bicycle world. Oh? Then let's get right to it. But don't forget that we still need some way to fully secure the constrain the tire bead radially to the rim. You have obviously conceived of a way to do that which involves no weight whatsoever. Please share. Get right to it? I'm merely responding you your statement "But that hardly establishes that such a bead reinforcement is absolutely necessary where there IS a sufficient mechanical (i.e. hooked or even interlocked) bead interface." I'm not even contesting your remark. I'm only saying that nobody is building such tires... Even though they would be substantially lighter and would sell faster then you could get them out of the mold. I wonder why? They do not exist yet you KNOW they would be lighter. A silly proposition. So you say.... Of course, if you remove some 160 inches of steel cable it will make things heavier. After all, several folks have "proved" that it is unnecessary by mounting tires with said cable cut. Oops, missed this. Do us all a favor and see if you can maintain consistency in the points you present. You assumed "removal of bead reinforcement" (with no suggestion of structure to replace its function) and asserted "lighter" which is not a reasonable assumption. Maybe it could be done, maybe it couldn't but your unsupported assumption cannot be allowed to stand. Now you are also suggesting "cut." Sorry dude, cut is neither "removed" nor "lighter." DR The discussion I read on this site and the JPG that was referenced showed a tire with the bead cut, in several places. No mention of additional reinforcement or anything else - other then one of the participants saying that when the tire pressure got to 100 psi he decided to split. Now then - you said "They do not exist yet you KNOW they would be lighter. A silly proposition." and I replied if you remove the wire it is going to get lighter, which is a logical deductions given that steel weighs more then rubber, nylon or other tire materials. Unless, that is, you are going to blunder off at a tangent and decide that while they removed the cable they somehow added something else to reinforce the bead.... like kevlar, carbon fiber, butcher's twine, etc. Oh yes, in closing. The entire thrust of this thread has been the requirement or lack there of in bead reinforcement. Now you seem to be saying that of course if you remove the wire you need to replace it with something..... Is that right? Originally you seemed to be saying that it wasn't needed and now you seem to be saying that if you remove the steel you need to replace it with something.... If that is your assertion I agree with you. Cheers, John B. |
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