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#31
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Tied and soldered spokes.
thirty-six wrote:
A tricycle wheel usually has cantilever axles which are thicker and make no difference to the strength of the wheel. and flange offset is greater on the dual track axle. The rear hubs on my Holdsworth trike are 3" across the flanges. The front hub on my son's Dawes road bike is 3" across the flanges. (I compared with the Dawes, because that's a normal hub. The front hub in the Holdsworth trike is a large flanged drum brake and narrower than a normal bike hub [1] - it needs spacers between the lock nuts and the fork ends.) The only trike wheels I have that are wider than normal are from atandem trike. A bicycle wheel can only be used for the single track axle, Well, yes, because that's the only place it will fit! if the machine is ridden hard. The high proportion of radial stability compared to lateral is pretty much determined by the shape of the space the wheel has to fit into. If the 3" flange spacing on 27/28" wheels was determined to be good a century ago and so standardized then, then it's good for today. Exactly. So if it's good, how can you say that wheels have too poor a lateral stability? [1] I do not know why it is narrower - it just is. -- Andrew |
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#32
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Tied and soldered spokes.
thirty-six wrote:
On 23 Nov, 22:29, Naqerj wrote: Ah, we're not talking about quite the same thing, I think. The motor cycle wheel I saw had a plastic failure of the rim - the rim ended up heart-shaped. Which doesn't mean it was not radially buckled and it is still a cycle wheel. Agreed - it is a bit like changing the rules in the middle of the game to disallow plastic failure at this point but, in fairness, it does seem to be what Ian meant all along, even if he didn't say it. After all, if you're determined enough, you can get plastic failure of a wheel in pretty much any direction you choose. -- Andrew |
#33
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Tied and soldered spokes.
On Wed, 25 Nov 2009, Naqerj wrote:
thirty-six wrote: On 23 Nov, 22:29, Naqerj wrote: Ah, we're not talking about quite the same thing, I think. The motor cycle wheel I saw had a plastic failure of the rim - the rim ended up heart-shaped. Which doesn't mean it was not radially buckled and it is still a cycle wheel. Agreed - it is a bit like changing the rules in the middle of the game to disallow plastic failure at this point but, in fairness, it does seem to be what Ian meant all along, even if he didn't say it. Eh? At what point was the conversation about anything other than buckling? I only recall discussion about radial buckling, so I'm at a loss to understand why it would automatically be assumed that all other modes of failure are deemed to be included. I said (the totality of my posting that started this part of teh thread) "Out of interest, however, has anyone ever seen a purely radial buckle on a bicycle wheel?" How is that NOT setting out that the case I was considering was buckling (indeed, _purely_ radial buckling). It was in response (with a few intervening postings) to teh assertion "Tying and soldering the spokes will diminish the possibility of a radial buckle in a lighweight rim when heavily loaded." In what possible way is it unclear that this was not about buckling? All teh stuff about analogy with euler struts - if it wasn't evidently an elastic regime, what did you think that was about? For the record, my comments were not addressing the case of melting of the wheel, either. Nor vaporisation, or combustion. In fact, there are a very great number of things that could happen to a wheel that render it non-serviceable, but which are not buckling, and I wasn't thinking about while discussing buckling. Also - since it's apparently reasonable to criticise someone for not saying what they are not talking about, I would like to clarify that my postings about bicycle wheels had nothing whatsoever to do with meringues, aardvarks, talcum powder or power-over-ethernet midspan injectors. I hope that clears up the outstanding confusion amongst people that thought that when talking about radial buckling of bicycle wheels I might have intended the topic of conversation to encompass lots of other things too. regards, Ian SMith -- |\ /| no .sig |o o| |/ \| |
#34
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Tied and soldered spokes.
On 25 Nov, 20:17, Naqerj wrote:
thirty-six wrote: A tricycle wheel usually has cantilever axles which are thicker and make no difference to the strength of the wheel. Yeah, but it means you cant use a bicycle wheel on the dual track axle, it must be a tricycle wheel. ; ) and flange offset is greater on the dual track axle. The rear hubs on my Holdsworth trike are 3" across the flanges. *The front hub on my son's Dawes road bike is 3" across the flanges. *(I compared with the Dawes, because that's a normal hub. *The front hub in the Holdsworth trike is a large flanged drum brake and narrower than a normal bike hub [1] - it needs spacers between the lock nuts and the fork ends.) The only trike wheels I have that are wider than normal are from atandem trike. What I was getting at was that the rim is offset to the flanges. I realise this is not necessarily always the case but that is what I have seen on lightweight tricycles. If the 3" flange spacing on 27/28" wheels was determined to be good a century ago and so standardized then, then it's good for today. Exactly. *So if it's good, how can you say that wheels have too poor a lateral stability? What wheel, what did I say? |
#35
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Tied and soldered spokes.
On 25 Nov, 20:27, Naqerj wrote:
thirty-six wrote: On 23 Nov, 22:29, Naqerj wrote: Ah, we're not talking about quite the same thing, I think. *The motor cycle wheel I saw had a plastic failure of the rim - the rim ended up heart-shaped. Which doesn't mean it was not radially buckled and it is still a cycle wheel. Agreed - it is a bit like changing the rules in the middle of the game to disallow plastic failure at this point but, in fairness, it does seem to be what Ian meant all along, even if he didn't say it. *After all, if you're determined enough, you can get plastic failure of a wheel in pretty much any direction you choose. I did manage to achieve radial plastic buckling of a bike rim through being pig-headed. It was not on the agenda. |
#36
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Tied and soldered spokes.
Ian Smith wrote:
On Wed, 25 Nov 2009, Naqerj wrote: thirty-six wrote: On 23 Nov, 22:29, Naqerj wrote: Ah, we're not talking about quite the same thing, I think. The motor cycle wheel I saw had a plastic failure of the rim - the rim ended up heart-shaped. Which doesn't mean it was not radially buckled and it is still a cycle wheel. Agreed - it is a bit like changing the rules in the middle of the game to disallow plastic failure at this point but, in fairness, it does seem to be what Ian meant all along, even if he didn't say it. Eh? At what point was the conversation about anything other than buckling? I only recall discussion about radial buckling, so I'm at a loss to understand why it would automatically be assumed that all other modes of failure are deemed to be included. According to my dictionary [1] 'buckle' means to crumple under pressure. This does not exclude plastic failure. Why do you insist on being so belligerently argumentative about everything? I said (the totality of my posting that started this part of teh thread) "Out of interest, however, has anyone ever seen a purely radial buckle on a bicycle wheel?" How is that NOT setting out that the case I was considering was buckling (indeed, _purely_ radial buckling). It was in response (with a few intervening postings) to teh assertion "Tying and soldering the spokes will diminish the possibility of a radial buckle in a lighweight rim when heavily loaded." In what possible way is it unclear that this was not about buckling? All teh stuff about analogy with euler struts - if it wasn't evidently an elastic regime, what did you think that was about? Now you're just being dishonest. The Euler strut business is obviously elastic but that posting came later, didn't it? You've just quoted the *totality* of your posting that started this and neither "Euler" or "strut" appears in it. Clearly, you believe that you are incapable of ever making any mistakes, however trivial, and will even redefine the language rather than compromise your illusion of infallibility. It's clearly pointless to try and have any sort of reasonable conversation with you, so I won't try to any longer. Goodbye. [1] Pocket Oxford was the one that fell to hand. -- Andrew |
#37
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Tied and soldered spokes.
thirty-six wrote:
What I was getting at was that the rim is offset to the flanges. I realise this is not necessarily always the case but that is what I have seen on lightweight tricycles. Oh, I see. I don't think that's generally the case though - none of my trikes has offset wheels and I've never noticed an offset on anyone else's trikes at TA rides. Mind you, I haven't been looking for it. I'll have to take more notice at our next gathering. It's a neat idea though. I was about to start arguing that such an offset would be pointless because, at first sight, it doesn't seem as if it would make any difference - it would increase lateral strength in one direction, but lessen it the other and, with a pair of wheels, the effect would near enough balance out. But then I realised that, when you're cornering quickly, most of the weight is on the outside wheel, so offsetting the rim towards the middle could be advantageous... I'm tempted to try it. Oh, come to think of it, I already have ... sort of ... a bit. But at the opposite end of the scale from a lightweight trike - it's an Ivy carrier tricycle dating from around 1910 - beaded edge rims and those strange solid rubber tyres that you only get on carrier trikes. You'd think a thing like that would be difficult to forget but, somehow, I often do when I'm talking about trikes. Maybe I don't think of it as coming into the category of trikes; it's better catalogued under deathtraps. Anyway, the front wheels have drum brakes on the inside. However, the outside flange, the hub body and the brake drum are not fixed to one another, which means that the brake can't transmit any torsion to the outer flange. So I spoked it tangentially on the inside and radially on the outside... If the 3" flange spacing on 27/28" wheels was determined to be good a century ago and so standardized then, then it's good for today. Exactly. So if it's good, how can you say that wheels have too poor a lateral stability? What wheel, what did I say? Ian said: I think you'll always get a lateral buckle from a wheel before you get a radial buckle. To which you replied If always, then wheels have too poor a lateral stability. The loads are predominantly radial so radial failures should be the dominant failure mode. ....but don't fret about it. -- Andrew |
#38
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Tied and soldered spokes.
On 26 Nov, 21:04, Naqerj wrote:
thirty-six wrote: What *I was getting at was that the rim is offset to the flanges. *I realise this is not necessarily always the case but that is what I have seen on lightweight tricycles. Oh, I see. *I don't think that's generally the case though - none of my trikes has offset wheels and I've never noticed an offset on anyone else's trikes at TA rides. *Mind you, I haven't been looking for it. I'll have to take more notice at our next gathering. It's a neat idea though. *I was about to start arguing that such an offset would be pointless because, at first sight, it doesn't seem as if it would make any difference - it would increase lateral strength in one direction, but lessen it the other and, with a pair of wheels, the effect would near enough balance out. *But then I realised that, when you're cornering quickly, most of the weight is on the outside wheel, so offsetting the rim towards the middle could be advantageous... I'm not entirely convinced it is advantageous and it may have been a peculiarity of a a local barrow builder. If an offset is beneficial II think the maximum woul be a 2:1 ratio. Because of the side forces a trike rider cannot avoid, it becomes more important to ensure interlacing stability. It was poor lateral stability on a racing wheel which promted me to look at the interlace significance. I'm tempted to try it. Oh, come to think of it, I already have ... sort of ... a bit. *But at the opposite end of the scale from a lightweight trike - it's an Ivy carrier tricycle dating from around 1910 - beaded edge rims and those strange solid rubber tyres that you only get on carrier trikes. *You'd think a thing like that would be difficult to forget but, somehow, I often do when I'm talking about trikes. *Maybe I don't think of it as coming into the category of trikes; it's better catalogued under deathtraps. *Anyway, the front wheels have drum brakes on the inside. However, the outside flange, the hub body and the brake drum are not fixed to one another, which means that the brake can't transmit any torsion to the outer flange. *So I spoked it tangentially on the inside and radially on the outside... If the 3" flange spacing on 27/28" wheels was determined to be good a century ago and so standardized then, then it's good for today. Exactly. *So if it's good, how can you say that wheels have too poor a lateral stability? What wheel, what did I say? Ian said: * I think you'll always get a lateral buckle from a wheel * before you get a radial buckle. To which you replied // If always, then [THOSE] wheels have too poor a lateral stability. Sorry if it was left a little ambiguous for you. *The loads * are predominantly radial so radial failures should be the dominant * failure mode. |
#39
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Tied and soldered spokes.
On Thu, 26 Nov 2009 20:06:37 +0000, Naqerj wrote:
Ian Smith wrote: On Wed, 25 Nov 2009, Naqerj wrote: thirty-six wrote: On 23 Nov, 22:29, Naqerj wrote: Agreed - it is a bit like changing the rules in the middle of the game to disallow plastic failure at this point but, in fairness, it does seem to be what Ian meant all along, even if he didn't say it. Eh? At what point was the conversation about anything other than buckling? I only recall discussion about radial buckling, so I'm at a loss to understand why it would automatically be assumed that all other modes of failure are deemed to be included. According to my dictionary [1] 'buckle' means to crumple under pressure. This does not exclude plastic failure. Why do you insist on being so belligerently argumentative about everything? You seem to have mis-spelled "accurate". I like to be accurate. In a technical discussion on a technical topic, I tend to assume that it's a pre-requisite to be accurate. If I wanted to discuss plastic failure, I would say something about plastic failure. I was specifically addressing the case of buckling, which seemed to be what 36 was specifically talking about, and as a consequence I only said anything about buckling. For some reason, when you realised that I was actually talking about what I was talking about you characterised this as "changing the rules in the middle of the game". Why do you insist on being so snide about everything? I said (the totality of my posting that started this part of teh thread) "Out of interest, however, has anyone ever seen a purely radial buckle on a bicycle wheel?" How is that NOT setting out that the case I was considering was buckling (indeed, _purely_ radial buckling). It was in response (with a few intervening postings) to teh assertion "Tying and soldering the spokes will diminish the possibility of a radial buckle in a lighweight rim when heavily loaded." In what possible way is it unclear that this was not about buckling? All teh stuff about analogy with euler struts - if it wasn't evidently an elastic regime, what did you think that was about? Now you're just being dishonest. The Euler strut business is obviously elastic but that posting came later, didn't it? You've just quoted the *totality* of your posting that started this and neither "Euler" or "strut" appears in it. "All the stuff" was subsequent in the thread - between the first post and the last post. I don't think it's dishonest to refer to things said in the thread. I didn't claim it was in the first post - indeed, I explicitly provided what was in the first post. I don't know how much clearer it can be that Euler struts wer enot in teh first post other than post the entirety of the thread into every single message. I did not say Euler struts was in my first post. I explicitly provided the totality of the first post, and there's nothing about struts in it. You've just decided to pretend I made claims I have not in order to make some more insinuations. Why so snide? Clearly, you believe that you are incapable of ever making any mistakes, however trivial, and will even redefine the language rather than compromise your illusion of infallibility. You forget that it is me that is using the word buckling to refer to buckling. It is you that is using the word "buckle" to mean (apparently) any failure of any sort (or at least, one of an undefined range of different failures). I'm quite happy to discuss other failure modes if you want to introduce them, but when I discuss buckling, I am (shock!) discussing buckling. You, on the other hand, would rather make repeated insinuation and accusation - now you've decided that me insisting that when I talk about buckling I'm talking about buckling must mean that I think I am incapable of making mistakes. Do you like presenting this nasty, poisonous, snide persona? regards, Ian SMith -- |\ /| no .sig |o o| |/ \| |
#40
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Tied and soldered spokes.
Response to Naqerj:
Anyway, the front wheels have drum brakes on the inside. However, the outside flange, the hub body and the brake drum are not fixed to one another, which means that the brake can't transmit any torsion to the outer flange. So I spoked it tangentially on the inside and radially on the outside... Same arrangement on the all-carbon Windcheetahs, if memory serves. -- Mark, UK. |
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