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  1. #76
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    I think that the OP might be yanking chains, not breaking them. More than a littel exaggeration on the internets, perhaps, to get some attention?
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  2. #77
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    Quote Originally Posted by forge55b View Post
    Assuming that all of this technobabble is even relevant is kind of funny.
    It's only relevant if you insist on seeing not just a bicycle manufacturer's warnings, but also some engineering reports before believing that if you're up around 240+, it's totally possible you could break stuff just because it's not designed to support your weight.

  3. #78
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    Quote Originally Posted by Nicole Hamilton View Post
    It's only relevant if you insist on seeing not just a bicycle manufacturer's warnings, but also some engineering reports before believing that if you're up around 240+, it's totally possible you could break stuff just because it's not designed to support your weight.
    Sounds like an attack on me seeing all this as nonsense but I'm far from close to 240 lbs, and actually under 200 lbs so breaking stuff due to weight doesn't seem to be the issue with me unless my chains were designed for featherweights or something.

    With that said, what's your point? What are you even trying to prove to everyone here with the constant replies? I don't think anyone is arguing that chains can break due to whatever reason. So arguing semantics on what force vs stress means seems like a moot point. (to me anyway) And that yes, there are specific ratings for components.

    But with that said, unless these limits are marked on each and every component, I doubt that anyone will call each company for every component they own to make sure that they aren't too fat to use it. The only thing that most people consciously consider weight limits for are wheels and frames. I doubt that most cyclists get a normal 10 spd chain and wonder, "hmm am I too fat for this chain?"

  4. #79
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    Quote Originally Posted by forge55b View Post
    With that said, what's your point?
    When people ask a question and I know the answer, I'll often share it. If someone insists that seems impossible, I'll try to explain. If they get nasty and insulting, I lose interest quickly. But otherwise, I assume good faith, that if it was interesting to me to learn how this stuff works and someone's asking about it, then maybe they find it interesting as well.

    If you're not interested in the answer, there's not much point in asking the question. But also, just because you started the thread doesn't mean you're the only case we might consider in a general discussion of what's going on. I hadn't paid attention to your weight and didn't care what it was (still don't care) except to note that, combined with your style of riding, you're likely at the design limits.

    Btw, I'm guessing you're using a long crank arm, probably at least 175s, and the problems most commonly happen when you're standing and you shift your weight from one pedal to the other on the small chainring, probably about the 1 o'clock position, is that correct?

  5. #80
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    Quote Originally Posted by Nicole Hamilton View Post
    Low is relative to the design limits.

    You may not believe me that engineers have special concerns about chains and how they snap, but it's easy to find papers like this one, opening paragraphs, emphasis added.

    http://deepblue.lib.umich.edu/bitstr...6.0001.001.pdf


    If you skip to the end, you'll see where he's produced a lot of graphs of computer simulations of the frequency response. The horizontal axises are in Hz (frequency) and you'll see regular patterns of peaks. Those are the harmonics I mentioned.

    Chains on modern bicycles are an engineering nightmare. Part of that's always been true because no engineer wants to run a chain system without an oil bath or at least a cover to keep the thing clean. But 40 years ago, chains could be big enough to solve the problem with brute force. Back then, if you'd asked somebody how often they replaced their chain, they'd look at you funny because almost nobody ever did. Today, with 10 or 11 cogs in there -- and you can only make the rear so wide without bumping feet -- the chains are way undersized. The tradeoff is that chains are now a routine wear item. And it also means that you really can snap them.

    There really is a reason Pinarello's user guide contains a warning for anyone over 200 lbs and stresses that above 240, you're risking failure even with new parts.
    The bottom line is that if you're breaking chains, you're either shifting wrong, running equipment too long, or "breaking" (as in with a chain tool) chains too frequently and/or incorrectly.

    The kicker here is that mountain bikes are likely far more abusive to chains than a road bike. Chain breakage is highly uncommon in any area and most breakages can be traced back to one of the reasons I (and others) listed. I seriously doubt that there's a rider on a "normal" bike on this planet that can BREAK a chain by simply pedaling. That's the bottom line here. It's cute as a "chest thumping" exercise to claim you can, but it's unrealistic.

  6. #81
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    Quote Originally Posted by cchase86 View Post
    It's cute as a "chest thumping" exercise to claim you can, but it's unrealistic.
    Ding ding! We have a winner.
    You get all the sleep you need when you are dead

  7. #82
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    Quote Originally Posted by Nicole Hamilton View Post
    Ooh, we got ourselves some literature. Seriously, though, not bad. Now if only you would understand what the article is talking about.

    Quote Originally Posted by Nicole Hamilton View Post
    If you skip to the end, you'll see where he's produced a lot of graphs of computer simulations of the frequency response.
    Yep. Did you actually look at these graphs? I know, numbers for you are just scribbles on paper, but you may want to take a look. You'll find that maximum dynamic loads under resonance conditions these authors have found are of the order of 600N, roughly corresponding to 135lbf. That's about 6% of the tensional strength of the bicycle chain. I know, sorry, here I go giving you numbers again that mean nothing to you, but for those of us who do understand numbers they tell us that there's no reason to worry about loads due to the inherent dynamics of the chain drive.

    I note that I won't even go into the details of the dynamical model that is being discussed here, and how it pertains to parameters that are typical for road bikes. Pearls before swine. I'll just say that you won't see excited vibrations of road bike chains since you're far from resonance. Believe me, you would notice if these resonances occur.

    Quote Originally Posted by Nicole Hamilton View Post
    Chains on modern bicycles are an engineering nightmare. Part of that's always been true because no engineer wants to run a chain system without an oil bath or at least a cover to keep the thing clean.
    That's complete and utter nonsense of course. Once again I would recommend you stick to things you know something about, whatever those may be.

    Quote Originally Posted by Nicole Hamilton View Post
    Today, with 10 or 11 cogs in there -- and you can only make the rear so wide without bumping feet -- the chains are way undersized. The tradeoff is that chains are now a routine wear item. And it also means that you really can snap them.
    More idle nonsense.

    Quote Originally Posted by Nicole Hamilton View Post
    There really is a reason Pinarello's user guide contains a warning for anyone over 200 lbs and stresses that above 240, you're risking failure even with new parts.
    Uhm, honey, you do understand that the warning you keep blabbering about is regarding the frame? That this has nothing whatsoever to do with your drivetrain? That's a rhetorical question, by the way.

  8. #83
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    Quote Originally Posted by Nicole Hamilton View Post
    When people ask a question and I know the answer, I'll often share it.
    That would be fine if, in fact, you knew the answer. Unfortunately, it turns out you don't understand the subject at all, and instead pull "facts" out of thin air, without even the most basic understanding at all.

    Case in point:

    Quote Originally Posted by Nicole Hamilton View Post
    Btw, I'm guessing you're using a long crank arm, probably at least 175s,
    My dear girl, the difference between such a "long" crank and the "standard" 170mm one amounts to a whopping 2.9%. Yeah I know, there I go again with those pesky numbers that mean nothing to you. For those of us who are not number blind, however, it means that the difference between crank lengths that are in common use on standard road bikes is completely immaterial. Variations in chain strength between different batches, or between differently worn chains, are typically a lot higher.

    Quote Originally Posted by cchase86 View Post
    The bottom line is that if you're breaking chains, you're either shifting wrong, running equipment too long, or "breaking" (as in with a chain tool) chains too frequently and/or incorrectly.
    Yep, that's the bottom line.

  9. #84
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    Quote Originally Posted by JustTooBig View Post
    I can see my instantaneous power peaks.
    Just curious. What power meters provide instantaneous readings? I had thought that even the really expensive ones only gave one-second averages.
    Fredke commented in your thread. You won't believe what happens next!

  10. #85
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    Quote Originally Posted by Nicole Hamilton View Post
    Because we don't care about wattage, given the way you're measuring it. You're getting an averaged-out measure; we need to look at the instantaneous peaks.
    No. That's what JTB means by technique.

    Millisecond transients are irrelevant to atheletic performance. What matters there is the lower-frequency averages (one second, ten seconds, etc.), which is the only athletically useful way to interpret JTB's comment.

    However regarding technique---something JTB brought up---if two cyclists are getting the same one-second average power but one is producing it smoothly while the other one is generating high-power transients that break equipment, we could sensibly call that bad technique.

    That's what I read JTB's comment as saying and that makes me think his take is more useful than nit-picking the issue of instantaneous vs. one-second averages.
    Fredke commented in your thread. You won't believe what happens next!

  11. #86
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    Quote Originally Posted by Pirx View Post
    Tensile strength for a high-quality 10-speed chain is about 2200 pounds.
    That's if the chain is loaded evenly. If there's torque on the chain (bad chain line or a hard shift while loaded), you can peel a plate off a pin with considerably less force.

    I've seen pretty lightweight guys who aren't gear-mashers break chains in this way on well-maintained bikes.
    Fredke commented in your thread. You won't believe what happens next!

  12. #87
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    Quote Originally Posted by Pirx View Post
    That would be fine if, in fact, you knew the answer. Unfortunately, it turns out you don't understand the subject at all, and instead pull "facts" out of thin air, without even the most basic understanding at all.

    Case in point:



    My dear girl, the difference between such a "long" crank and the "standard" 170mm one amounts to a whopping 2.9%. Yeah I know, there I go again with those pesky numbers that mean nothing to you. For those of us who are not number blind, however, it means that the difference between crank lengths that are in common use on standard road bikes is completely immaterial. Variations in chain strength between different batches, or between differently worn chains, are typically a lot higher.



    Yep, that's the bottom line.

    It's not worth it man. She's a lonely old loon who lives with a cat, rides a $6500 carbon pinarello on MUTs exclusively, only washes her shorts every three rides, thinks she knows everything, really knows nothing and gets pissed off at anyone (which is everyone) who proves her wrong. This is about the 5th time I've seen the same stupid argument out of her, along with the ever present "I'm an engineer, what are you?" flashing of their qualifications. When she finally gets frustrated to the point where she starts going in circles, claiming that "you can believe whatever you want, because I'm right anyway" is the point which she puts you on the ignore list and continues on her merry way until the next person calls her out.
    It's a definite pattern, and you're better off not wasting time with someone who's just here to argue for the sake of arguing.

    OP: if you're breaking things, buy beefier parts in the future. If you continue to break those, consider looking at your technique or maintenance as the culprit.
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  13. #88
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    Quote Originally Posted by Fredke View Post
    That's if the chain is loaded evenly. If there's torque on the chain (bad chain line or a hard shift while loaded), you can peel a plate off a pin with considerably less force.

    I've seen pretty lightweight guys who aren't gear-mashers break chains in this way on well-maintained bikes.
    I weigh 142 pounds. I broke a 9 speed chain on my CAAD a number of years back while sprinting up the crest of a climb in an anaerobic haze. I made a stupid shift under power just to get a little taller gear and *poof*. Just as you pointed out, I sheared the side plate right off the pin and the chain popped.

    With the right application of force, anything can be broken.
    Quote Originally Posted by bigrider View Post
    Teh Lounge- "Its not just for weirdos anymore. It is for those trying to escape the noobsauce questions."
    Quote Originally Posted by QuiQuaeQuod View Post
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  14. #89
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    Quote Originally Posted by Fredke View Post
    That's if the chain is loaded evenly. If there's torque on the chain (bad chain line or a hard shift while loaded), you can peel a plate off a pin with considerably less force.
    Oh absolutely, I agree. I'm sure you didn't read this whole silly clownishness in here, but I had mentioned this in one of my earlier posts.

    Quote Originally Posted by robdamanii View Post
    It's not worth it man.
    Yeah, that's probably true. I see you have more experience with her than I do...

    Quote Originally Posted by robdamanii View Post
    With the right application of force, anything can be broken.
    Yeah, I agree that the OP must be doing not only one, but several things wrong. Damaging the splines on his freehub the way he has shown is quite a feat. I still wonder how he managed to do that.

  15. #90
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    Quote Originally Posted by Pirx View Post
    Oh absolutely, I agree. I'm sure you didn't read this whole silly clownishness in here, but I had mentioned this in one of my earlier posts.



    Yeah, that's probably true. I see you have more experience with her than I do...



    Yeah, I agree that the OP must be doing not only one, but several things wrong. Damaging the splines on his freehub the way he has shown is quite a feat. I still wonder how he managed to do that.
    Well, I can say from experience that soft aluminum freehubs (*ahem*americanclassic*ahem*) and cassettes that are made of single steel cogs bolted together or even loose (no carrier, usually bottom of the model line cassettes) are not a good mix. For that reason I always use a cassette that has the largest 3 or 4 cogs together on a carrier.

    After swapping to a more durable freehub and a cassette with a carrier, no problems since.
    Quote Originally Posted by bigrider View Post
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    Quote Originally Posted by QuiQuaeQuod View Post
    Trolling the lounge is like noodling for piranha.


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  16. #91
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    Quote Originally Posted by Fredke View Post
    That's if the chain is loaded evenly. If there's torque on the chain (bad chain line or a hard shift while loaded), you can peel a plate off a pin with considerably less force.

    I've seen pretty lightweight guys who aren't gear-mashers break chains in this way on well-maintained bikes.
    I agree. That would be an easy way for anyone to break a chain. Even if it doesn't break, you'll weaken it.

  17. #92
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    Quote Originally Posted by Fredke View Post
    That's what I read JTB's comment as saying and that makes me think his take is more useful than nit-picking the issue of instantaneous vs. one-second averages.
    Apologies if I appeared to be nit-picking.

    I like your point about torque. Figuring how a chain will work is a deceptively complex proposition when it's not just holding a load, but running around in a working machine, especially when you add derailleurs and times when the chain is stretched between chainrings, (and note, this happens working as designed, not just under conditions of rider abuse).

    My point about instantaneous is that word means something different in an engineering lab, where things get measured in microseconds for mechanical things and nanoseconds for anything electronic. If you were trying to test an engineering model for a chain, the sensors anyone would have on their bicycle would never be sufficient to tell you anything. In the particular paper I cited, the author was modeling behavior of his hypothetical chain to 500 Hz; to test that by instrumenting a physical machine he'd need to sample at 2x that (Nyquist rate), meaning 1000 samples/second. You can't do that with anything I know of that any consumer can easily buy for his bicycle.

  18. #93
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    Quote Originally Posted by robdamanii View Post
    It's not worth it man. She's a lonely old loon who lives with a cat, rides a $6500 carbon pinarello on MUTs exclusively, only washes her shorts every three rides, thinks she knows everything, really knows nothing and gets pissed off at anyone (which is everyone) who proves her wrong. This is about the 5th time I've seen the same stupid argument out of her, along with the ever present "I'm an engineer, what are you?" flashing of their qualifications. When she finally gets frustrated to the point where she starts going in circles, claiming that "you can believe whatever you want, because I'm right anyway" is the point which she puts you on the ignore list and continues on her merry way until the next person calls her out.
    It's a definite pattern, and you're better off not wasting time with someone who's just here to argue for the sake of arguing.
    And you are the person who decided to ignore repeated Moderator warnings about personal insults and letting this go and using the ignore function. So you get a long posting vacation and no more warnings.
    Dr. Cox: Lady, people aren't chocolates. Do you know what they are mostly? Bastards. Bastard-coated bastards with bastard fillings. But I don't find them half as annoying as I find naive bubble-headed optimists who walk around vomiting sunshine.

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