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Is it normal wheels go out of true after a fall?

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Is it normal wheels go out of true after a fall?

Old 09-14-22, 03:56 PM
  #76  
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Originally Posted by Ev0lutionz
Ran over a really bad bump, next time I knew I was falling on the drive side, handlebars took most of the brunt, RD had some scratches, steering went out of alignment, but I still could continue 150km after the fall.

Checked my bike by turning it upside down today and realized both wheels are slightly out of true, not sure how could this be given the handlebar took most of the brunt when kissing the tarmac..
Completely normal and predictable/ While modern wheels are MUCH less likely to go out of true than wheels were 20+ years ago, crashes and potholes very commonly knock wheels out of true.
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Old 09-14-22, 05:05 PM
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Originally Posted by Yan
Can we not use these cop out words like "probably"? Will it or will it not? If you don't know just say you don't know.
I’m not going to say one way or the other because, as I said, this is a poor model for a bicycle wheel. Just poking a stick or rod or anything into the ground (or something else) isn’t anything like a bicycle wheel in a corner. If you need another model to consider, think of a broom or a hoe or even poking the spear into something and picking it up. In other words, put a lateral force on it.

But anyway I don't have a problem if you want to change the stick to a different object. The physics are all the same. However when you say you apply force to the broom, it sounds like you're saying you're using both hands. One hand at the end of the handle, a second hand in the middle of the handle. That's not accurately translating the scenario I gave you. I told you you could only apply force to the top point.
Again, where on a bicycle do you push down on the wheels during cornering with only an axial load? Do you agree that a bicycle wheel undergoes centripetal force in a corner? That’s a lateral force that you say doesn’t exist.

If you didn't hold the middle of the broom, but instead only pushed down on a LEANING broom at the very top of the handle with your palm, (1) would the bristles still ALWAYS collapse in the same direction, under your belief system? Or would it collapse randomly in either direction every time your try? (2) If you think it will always collapse in one direction, which direction is that? Concave side or convex side toward the ground?

Please answer the labeled questions.
If the broom is new with no previous curve imparted through use, the bristles would collapse in every direction. If you did it over and over again with the same broom, a pattern would eventually develop but that is because the damage of the initial collapse would introduce a weak spot that would bend in the same place upon each subsequent collapse. But if a new broom is used each time, predicting the direction of collapse of any individual bristle would be impossible.
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Old 09-14-22, 07:13 PM
  #78  
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Damn it all to hell you guys, first I had pasta for supper, but now I need to sweep the bloody kitchen floor!!!
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Old 10-03-22, 05:02 PM
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Sorry for leaving you hanging, I'm back from a climbing trip.

Originally Posted by cyccommute
If the broom is new with no previous curve imparted through use, the bristles would collapse in every direction. If you did it over and over again with the same broom, a pattern would eventually develop but that is because the damage of the initial collapse would introduce a weak spot that would bend in the same place upon each subsequent collapse. But if a new broom is used each time, predicting the direction of collapse of any individual bristle would be impossible.
So now you admit it is impossible to predict the way the bristles would collapse. But earlier you were adamantly against this with the spaghetti, even though it's the exact same scenario. Glad I could help you see the light on this. Now let's move on to the next part:

Originally Posted by cyccommute
Again, where on a bicycle do you push down on the wheels during cornering with only an axial load? Do you agree that a bicycle wheel undergoes centripetal force in a corner? That’s a lateral force that you say doesn’t exist.
Yes, of course there is a centripetal force but you forgot something. Let's say you are taking a left corner. You are turning left but your inertia wants to go straight. Your inertial is pushing rightward. That's the force you believe is bending the wheel. But let me explain the part you tragically forgot:

At the same time you are turning left, your entire bike is also leaned to the left. Since you are leaned to the left, the force of gravity naturally imparts a leftward force on you as it pulls you downward.

The leftward force originating from gravity perfectly cancels out the rightward force originating from your inertia wanting to keep going straight. Due to this perfect cancellation, there is no lateral force as far as the bike is concerned. It is zero.

But why is this cancellation so miraculously perfectly balanced? You ask? Because when you were 6 years old learning to ride a bike, you trained your inner ear and brain to send constant micro-corrections to your hands. That's how balancing on a bike works. This is why learning to ride a bike takes time. If you screw up perfectly canceling out the centripetal force against the leaning gravity force, your turn fails and you fall flat on your face.

Since the left and right forces are perfectly cancelled out when you turn, the force experienced by your bike frame and wheels is purely axial.

Are we clear now?

This is dead simple to observe. Winter is coming. Pay attention to how your snot drips off your nose when you turn. It's going to hit your headset every time. It's not going to fling off to the side after it departs your nose. If you live in a warm climate, hold a plumb bob in your teeth while you turn. You'll notice that it always stays axial with your wheels.

Last edited by Yan; 10-03-22 at 05:16 PM.
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Old 10-03-22, 06:16 PM
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Most wheels are made to be as light as possible and not as strong as possible. For touring I made my own wheels and used 4 cross lacing to make them as durable as possible. A lot depends on the tire in terms of the protection it can provide for the rim. Different strengths of spokes and different designs that are more or less likely to break. The easiest place to cut corners for a bike company is with the spoke and rims that are used.
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Old 10-03-22, 10:15 PM
  #81  
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Originally Posted by Calsun
Most wheels are made to be as light as possible and not as strong as possible.
I disagree. Many mid-grade road bikes out there come with 32 or 28 spoke wheels laced to heavy but cheap hubs with middle weight rims and straight gauge spokes. They are going for cheap, not light OR strong. Aftermarket wheels, on the other hand, are built for specific purposes. While most are lightweight for racing, there are tons of 32 DB spoke 3 cross wheels out there for durability, 40 spoke 4 cross wheels for tandems, etc.
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Old 10-03-22, 10:41 PM
  #82  
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Originally Posted by Yan
So now you admit it is impossible to predict the way the bristles would collapse. But earlier you were adamantly against this with the spaghetti, even though it's the exact same scenario. Glad I could help you see the light on this. Now let's move on to the next part:
Oh gods! Here we go again. I am the one who said it is impossible to predict the way something collapses. You’ve said “[the spaghetti] always buckles on the same side of its strand no matter which direction you lean it.” I have always maintained that it is impossible to predict which way something will collapse.

Yes, of course there is a centripetal force but you forgot something. Let's say you are taking a left corner. You are turning left but your inertia wants to go straight. Your inertial is pushing rightward. That's the force you believe is bending the wheel. But let me explain the part you tragically forgot:
Nope. You have it wrong again. I agree that the inertia is trying to make the bike go straight. Centripetal force and friction on the tires is pulling the bike around the corner away from the straight line inertia it wants to follow. This is not the force that is bending the wheel. The force may be trying to roll the tire off the wheel but it is not the force that is bending the wheel.

And I “tragically forgot” nothing.

At the same time you are turning left, your entire bike is also leaned to the left. Since you are leaned to the left, the force of gravity naturally imparts a leftward force on you as it pulls you downward.
Yep. And the force of gravity is working on the center of gravity which is significantly displaced from the contact patch.

The leftward force originating from gravity perfectly cancels out the rightward force originating from your inertia wanting to keep going straight. Due to this perfect cancellation, there is no lateral force as far as the bike is concerned. It is zero.
Nope. The lateral force is still the centripetal force (and friction) acting on the wheel. If it goes to zero…for example the bike losing traction in the corner or you just exit the corner…inertia takes over and the bike goes to a straight line again. Not the straight line that the bike originally entered the corner with but a line that is tangent to the portion of the curve where the lateral force when to zero.

Meanwhile, at the contact patch, the displaced center of gravity is leveraging the rim upwards as gravity pulls the bike downward.

But why is this cancellation so miraculously perfectly balanced? You ask? Because when you were 6 years old learning to ride a bike, you trained your inner ear and brain to send constant micro-corrections to your hands. That's how balancing on a bike works. This is why learning to ride a bike takes time. If you screw up perfectly canceling out the centripetal force against the leaning gravity force, your turn fails and you fall flat on your face.
It’s only “balanced” as long as you don’t exceed the friction of the tires. Your skills can keep that from happening but that has little to do with the forces involved.

Since the left and right forces are perfectly cancelled out when you turn, the force experienced by your bike frame and wheels is purely axial.
The sum of the downward force vector and the centripetal force vector can appear to be axial but the forces involve are still there and, when acting on the contact patch and a tensioned wheel will result in upward bending of the rim at the contact patch. That upward bend is analogous to the upward force put on the rim when the downward force is horizontal.

Are we clear now?
No. We are clear. I have been clear all along and you have been wrong.

This is dead simple to observe. Winter is coming. Pay attention to how your snot drips off your nose when you turn. It's going to hit your headset every time. It's not going to fling off to the side after it departs your nose. If you live in a warm climate, hold a plumb bob in your teeth while you turn. You'll notice that it always stays axial with your wheels.
First, EWWWW! Second, so wrong. If you are cornering properly, you nose should be angled away from the headset. Snot from your nose will be under the influence of gravity and will drop straight down perpendicular to the ground. It will not fall at an angle towards the headset. Physics does not work that way.
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Old 10-04-22, 12:20 AM
  #83  
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Originally Posted by cyccommute
Oh gods! Here we go again. I am the one who said it is impossible to predict the way something collapses. You’ve said “[the spaghetti] always buckles on the same side of its strand no matter which direction you lean it.” I have always maintained that it is impossible to predict which way something will collapse.
Nope. Nice attempt at attempting to save face after losing hehe. You were adamant that with the broom/spaghetti leaning, it would always collapse the same way. Now you've admitted it would collapse in a random way.

I see you tried to cheat the argument by misquoting me. Where you quoted me I was talking about vertical spaghetti buckling due to built in weakness (which you also admitted in your last post fyi). In my most recent challenge to you where you finally admitted your mistake, we were talking about a leaning situation.

Originally Posted by cyccommute
Physics does not work that way.
This is about frame of reference. You are turning left and your bike is leaning left. Your nose is to the left of the headset. The moment the snot leaves your nose it's going to begin flying in a straight line along the tangent. It will no longer be taking a curved path. Meanwhile you are continuing your curve left. By the time the snot has dropped near the headset, the bike frame has curved left to meet it. As you can see, from the perspective of a person standing nearby, the snot is traveling perpendicular toward the ground, but from the frame of reference of the cyclist, the snot is falling diagonally toward the centerline of the frame. We are analyzing forces on the bike, so we have to analyze in the frame of reference of the bike, not in the frame of reference of a stationary outside observer. Understand now?

In the same way, the bike (including the wheel) is experiencing a purely "downward" force, where the "downward" is not perpendicular to the ground, but instead leaned at an angle. It is 100% downward in its own frame of reference. Since the force is completely in plane with the wheel, there is no sideways force trying to bend the wheel into a taco.

Were you able to follow along with my explanation? I tried to make it clear.

Originally Posted by cyccommute
...will be under the influence of gravity and will drop straight down perpendicular to the ground. It will not fall at an angle towards the headset.
I'm glad you stated your belief in such a clear way. Now you cannot back away from it. Let us cut through all your self-confused mumble jumbo and end the argument right here. You're saying that if you hold a plumb bob in your teeth while riding in a circle, the plumb bob will not fall toward the headset. You are saying it will fall perpendicular to the ground.

Are you willing to take a bet? If you agree I will go out and make a video the next day. Whichever one of us loses agrees to sit his dumb ass down.

I have a bike with aerobars. I can use the aerobars to hang the plumb bob instead of my teeth. This way it will be impossible for me to move my head around and cheat. I will then ride in a circle and record the result with my phone. We will be able to see whether the plumb bob falls perpendicularly toward the ground as you claim, or falls toward the tire (bike center line) as I claim.

What is your response? Accept the bet or not?

Last edited by Yan; 10-04-22 at 07:39 AM.
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Old 10-04-22, 09:09 AM
  #84  
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Originally Posted by Yan
Nope. Nice attempt at attempting to save face after losing hehe. You were adamant that with the broom/spaghetti leaning, it would always collapse the same way. Now you've admitted it would collapse in a random way.
Now you are making thing ups. I have always been adamant that something collapsing will collapse in a random manner. You are the one who has maintained that they always collapse in the same direction. I did not misquote you. That is a direct quote. Here’s another from post 59

This is because that spaghetti already has a built in imperfection, an existing slight bend in it, so no matter what you do it's just going to bend in the same way as that existing bend. This is buckling. There is no external lateral force here. Your entire input force is axial. If you take a different spaghetti, that second spaghetti will have a different imperfection so it will buckle in it's own way. But it's always the same. You will never find a spaghetti that buckles in a 360 degree random direction each time you press down, because such a theoretically perfect spaghetti does not exist.
My post 60 is a response to your statement even doing your silly experiment. The spaghetti bends and breaks in a random direction.

I see you tried to cheat the argument by misquoting me. Where you quoted me I was talking about vertical spaghetti buckling due to built in weakness (which you also admitted in your last post fyi). In my most recent challenge to you where you finally admitted your mistake, we were talking about a leaning situation.
I have not misquoted you. One of your quotes is above in full. The bolded text says that the spaghetti “never” buckles in a random direction. You seem to be saying something completely different not. I admit that spaghetti isn’t a strong material and has weaknesses but those weaknesses are completely random which means that it will break in a random direction when force is applied. All materials have internal weaknesses from inconsistencies of the materials and all materials are going to buckle in a random direction if subjected to a vertical force. If a lateral force is applied, they will buckle in the direction of the lateral is pushing.

This is about frame of reference. You are turning left and your bike is leaning left. Your nose is to the left of the headset. The moment the snot leaves your nose it's going to begin flying in a straight line along the tangent. It will no longer be taking a curved path. Meanwhile you are continuing your curve left. By the time the snot has dropped near the headset, the bike frame has curved left to meet it. As you can see, from the perspective of a person standing nearby, the snot is traveling perpendicular toward the ground, but from the frame of reference of the cyclist, the snot is falling diagonally toward the centerline of the frame. We are analyzing forces on the bike, so we have to analyze in the frame of reference of the bike, not in the frame of reference of a stationary outside observer. Understand now?
Again…EWWWWW! Yes, this is about frame of reference but once the snot leaves your nose (EWWWW!), it falls out of the frame of reference of the bike and enters its own frame of reference. Once dropped, the snot (EWWWW!) drops straight down due to gravity (let’s ignore aerodynamics) and, at the same time, takes a straight line path away from the corner. It does not fall towards the centerline of the frame and, in fact, travels away from the frame at a tangent to the corner. The combined motions will form an arc but away from the frame and definitely not straight down the frame.

In the same way, the bike (including the wheel) is experiencing a purely "downward" force, where the "downward" is not perpendicular to the ground, but instead leaned at an angle. It is 100% downward in its own frame of reference. Since the force is completely in plane with the wheel, there is no sideways force trying to bend the wheel into a taco.
The problem here, again, is that you are trying to put the bike into a frame of reference that you are not justified to put it into. The forces working on the bike are not forces in the frame of reference. They are external to it. The angle of the bicycle is a result of the action of the normal force and the centripetal force. The angle is the sum of those two forces but the individual forces are still there and still acting on the bicycle.

Were you able to follow along with my explanation? I tried to make it clear.
Well I can follow your explanation but it is still wrong. You are making wrong assumptions.

I'm glad you stated your belief in such a clear way. Now you cannot back away from it. Let us cut through all your self-confused mumble jumbo and end the argument right here. You're saying that if you hold a plumb bob in your teeth while riding in a circle, the plumb bob will not fall toward the headset. You are saying it will fall perpendicular to the ground.
A plumb would be different from a free snot body (EWWW!) because it is constrained and attached to the bike. It is a semi-free body and the angle at which if falls is going to be highly influenced by the weight of the bob. If dropped, it would fall down and away from the corner. Once it hits the end of its line, it is no longer a free body and will take an angle but that angle wouldn’t necessarily be the same as that of the bicycle.
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Old 10-04-22, 11:54 AM
  #85  
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Yes, I knew you would cop out of the bet challenge in a cowardly way, because that would prove you wrong and you don't like to admit it.

Originally Posted by cyccommute
A plumb would be different from a free snot body (EWWW!) because it is constrained and attached to the bike. It is a semi-free body and the angle at which if falls is going to be highly influenced by the weight of the bob. If dropped, it would fall down and away from the corner. Once it hits the end of its line, it is no longer a free body and will take an angle but that angle wouldn’t necessarily be the same as that of the bicycle.
First of all, stop with the repeated "EWW" because it's giving me the creeps. This is just a hypothetical discussion. What's with the this exaggerated child language? Are you a teen girl?

I bolded the part above where you are talking about the behavior of the bob when you drop it, before it becomes tight. I underlined the words after that to prove that you are talking about the freefalling phase. You are not talking about after the line become tight. Don't try to wiggle out of this with some lame excuses. Be a man and own the things that you wrote. Anyway as we established, at this point the line is not involved. The bob is just an independently free falling object. You say "if dropped, it would fall down and away from the corner". But wait, two posts ago your claim was that a dropped object would fall perpendicular to the ground (see quote blow). What happened? It's not straight down perpendicular to the ground anymore? It will "fall away from the corner" now? You changed your mind and there IS an angle now after all??? Did the laws of physics change between yesterday and today in your brain? Hello???

Originally Posted by cyccommute
Second, so wrong. Snot from your nose will be under the influence of gravity and will drop straight down perpendicular to the ground. It will not fall at an angle...
Have a look at the two bolded statements above and realize how hilarious it is that you made a complete 180 without even realizing it. Let me explain to you why you are posting these contradictory statements that change from one post to the next: you have an intuitive understanding of how objects behave; however, at some point in your past you acquired false knowledge about physics. Now that you are confronted by the paradox between your intuition and your false knowledge, your brain is incapable of processing the conflict. You are gyrating. We are witnessing your unraveling in real time.

Anything else you would like to add before I check out of this thread and leave you in your humiliation? I got burnt by your psycho gaslighting last time so this time I will be sure to kick you a few times while you are down.

Last edited by Yan; 10-04-22 at 12:10 PM.
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Old 10-04-22, 12:34 PM
  #86  
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You guys are great! I completely understand what cyccommute is saying…but BT is the one who is more correct in the main. BT…it appears you are mixing words some times (as I read it) —. You and Cyccommute actually are both saying the object drops straight down…but you are clarifying (correctly I believe) that the bike is turning INTO that object’s perpendicular drop so RELATIVE to the rider, the dropped object “moves away” to the right (if the bike is turning left.). I think cyccommute agrees with that, he just explains it differently.
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Old 10-04-22, 02:39 PM
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Originally Posted by Sonofamechanic
You guys are great! I completely understand what cyccommute is saying…but BT is the one who is more correct in the main. BT…it appears you are mixing words some times (as I read it) —. You and Cyccommute actually are both saying the object drops straight down…but you are clarifying (correctly I believe) that the bike is turning INTO that object’s perpendicular drop so RELATIVE to the rider, the dropped object “moves away” to the right (if the bike is turning left.). I think cyccommute agrees with that, he just explains it differently.
You are 100% correct that I'm mixing words. But do you know why? I'm a veritable wordsmith here trying every which way to rephrase these simple explanations over and over again, with the bleak hope that one of the ways will get through to him. Inevitably to an outside listener I'm going to sound repetitive. But one hopes... It seems I have not been successful. At this point I doubt I will ever be.

Cyccommute remembers just enough physics vocabulary from his school days to fake an imitation of understanding, but he forgot all the rules of how the words are put together. The result is a total clusterf***. He's like a kid who remembers + - × ÷ but forgot about order of operations. Here is a case of knowing 50% being worse than knowing nothing at all. At least if you know nothing then you know you know nothing. When you know just barely enough to cause you to falsely believe that you know, but in reality you actually don't know... this is just tragic... Combine that with false confidence... it's game over right there.

I'm not saying he's doing it intentionally. I know he genuinely believes he is right. There are many areas in life where conviction goes a long way. Unfortunately this isn't one of them. There's no real latitude for interpretation in this kind of grad school science. At first I thought he knew the concepts but was just applying vocabulary incorrectly. But at one point I brought up the velodrome example, and when he responded incorrectly I knew immediately that it was the other way around. He knew the vocabulary but didn't understand the concepts. The worst possible combination. Right there I figured he was probably beyond salvage. It's easy to teach A kids because they are stars. It's easy to teach F kids because they know nothing and you simply teach everything from scratch. But when you get to the C and D kids... that's what drives people to quit teaching. There is an insurmountable valley of ghoulish unmalleability here, it's soul crushing to watch let alone participate in.

That's my verdict. Sorry if I offended anyone.

Last edited by Yan; 10-04-22 at 03:04 PM.
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Old 10-04-22, 03:07 PM
  #88  
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Having followed this thread off and on it seems to me that Yan is the only one who is disrespecting the other with his insulting references to Stuart's abilities. This is, of course, independent to the discussion or the logic used. It's too bad that some feel the need to describe their debating opponent with such characterizations, just like our current political state here in the USA. At some point one gets tired of reading this type of interaction. Andy (who in his long ago debate class learned to never attack the other's character, just their logic and facts)
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Old 10-04-22, 03:32 PM
  #89  
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Originally Posted by Yan
I just got done with you on that brake heat debate and am not really interested in debating you on yet one more of your physics misconceptions.
Yet here we are, 5 pages and almost a month later.

Spaghetti, bristles, snot... this has been entertaining.
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Old 10-04-22, 04:18 PM
  #90  
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This thread need less arguing and more spaghetti and bikes with arrows drawn on them.
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Old 10-04-22, 06:16 PM
  #91  
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Originally Posted by Kapusta
This thread need less arguing and more spaghetti and bikes with arrows drawn on them.
Agreed!!! I did my part to add two photos with sarcastic arrows drawn all over…but people took them seriously!!
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Old 10-04-22, 06:50 PM
  #92  
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Originally Posted by Sonofamechanic
Agreed!!! I did my part to add two photos with sarcastic arrows drawn all over…but people took them seriously!!
It was good work,
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Old 10-05-22, 06:26 AM
  #93  
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Ceteris paribus, thinking about the physics of riding while cornering will take the rider's full attention off of the road ahead, causing him to hit a bump and crash which will result in wheels that are out of true. Ergo, physics damages rims! Caveat Emptor! ​​​​​​​
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Old 10-05-22, 08:04 AM
  #94  
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Originally Posted by Yan
You are 100% correct that I'm mixing words. But do you know why? I'm a veritable wordsmith here trying every which way to rephrase these simple explanations over and over again, with the bleak hope that one of the ways will get through to him. Inevitably to an outside listener I'm going to sound repetitive. But one hopes... It seems I have not been successful. At this point I doubt I will ever be.

Cyccommute remembers just enough physics vocabulary from his school days to fake an imitation of understanding, but he forgot all the rules of how the words are put together. The result is a total clusterf***. He's like a kid who remembers + - × ÷ but forgot about order of operations. Here is a case of knowing 50% being worse than knowing nothing at all. At least if you know nothing then you know you know nothing. When you know just barely enough to cause you to falsely believe that you know, but in reality you actually don't know... this is just tragic... Combine that with false confidence... it's game over right there.

I'm not saying he's doing it intentionally. I know he genuinely believes he is right. There are many areas in life where conviction goes a long way. Unfortunately this isn't one of them. There's no real latitude for interpretation in this kind of grad school science. At first I thought he knew the concepts but was just applying vocabulary incorrectly. But at one point I brought up the velodrome example, and when he responded incorrectly I knew immediately that it was the other way around. He knew the vocabulary but didn't understand the concepts. The worst possible combination. Right there I figured he was probably beyond salvage. It's easy to teach A kids because they are stars. It's easy to teach F kids because they know nothing and you simply teach everything from scratch. But when you get to the C and D kids... that's what drives people to quit teaching. There is an insurmountable valley of ghoulish unmalleability here, it's soul crushing to watch let alone participate in.

That's my verdict. Sorry if I offended anyone.
Yan, shoot it should be Yawn. This certainly turned into a boring read.
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Old 10-05-22, 08:31 AM
  #95  
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Originally Posted by Mr. 66
Yan, shoot it should be Yawn. This certainly turned into a boring read.
oh, come on…… you don’t see the irony and humor in the juxtaposition of Yan’s consistent understanding of physics followed by his incongruous, disconnected phrases like “an insurmountable valley of ghoulish unmalleability” ? I mean…how does one exactly ‘surmount’ a ‘valley’ ? or, extending, how would you ‘surmount’ the ‘unmalleable’? Yan is having fun.
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Old 10-06-22, 10:07 AM
  #96  
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Originally Posted by Yan
Yes, I knew you would cop out of the bet challenge in a cowardly way, because that would prove you wrong and you don't like to admit it.



First of all, stop with the repeated "EWW" because it's giving me the creeps. This is just a hypothetical discussion. What's with the this exaggerated child language? Are you a teen girl?
To quote the great Foghorn Leghorn, “I say, I say, it’s a joke, son!”. Trying to keep it light.

Anything else you would like to add before I check out of this thread and leave you in your humiliation? I got burnt by your psycho gaslighting last time so this time I will be sure to kick you a few times while you are down.
Please, check out of this thread. I assure you that you are not leaving me humiliated. Frankly, I tire of your constantly dragging the discussions in every direction possible while never addressing the issue. From long, long, long, ago, the wheel is subjected to lateral force. Period.
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Old 10-06-22, 10:15 AM
  #97  
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Originally Posted by Sonofamechanic
You guys are great! I completely understand what cyccommute is saying…but BT is the one who is more correct in the main. BT…it appears you are mixing words some times (as I read it) —. You and Cyccommute actually are both saying the object drops straight down…but you are clarifying (correctly I believe) that the bike is turning INTO that object’s perpendicular drop so RELATIVE to the rider, the dropped object “moves away” to the right (if the bike is turning left.). I think cyccommute agrees with that, he just explains it differently.
Just to be clear, I tried Yan’s “snot” experiment yesterday. I took a mouthful of water, went hard into a corner, dropped water from my mouth on the inside of the corner as I went around the corner, and watched it fall. It did not fall in a line with the bicycle frame. It fell at an angle to the frame that “appeared” to be straight down. None of it hit the bicycle frame. The acceleration…from that “nonexistant” lateral force…is too small in a bicycle to have much of a lateral movement of a small object like water. There was some aerodynamic movement of the water, of course but not that much.
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Old 10-06-22, 10:39 AM
  #98  
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Lol…i was going to comment that water is not as stringy as….but you are right…better we let this go….
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Old 10-06-22, 10:46 AM
  #99  
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Originally Posted by cyccommute
To quote the great Foghorn Leghorn, “I say, I say, it’s a joke, son!”. Trying to keep it light.

Please, check out of this thread. I assure you that you are not leaving me humiliated. Frankly, I tire of your constantly dragging the discussions in every direction possible while never addressing the issue. From long, long, long, ago, the wheel is subjected to lateral force. Period.
You think we are going off topic? We are not off topic, we just dipped down to lower grade level. How are you going to understand grade 8 physics when you don't know grade 7 physics? Now you are complaining about wanting to go back up to grade 8? Is this a joke?
I've tried to child-explain these concepts to you six different ways to no avail. When at first you didn't get it, I dropped down to lower grade level material. Now I have realized you don't know the lower grade material either. Do I have to start dipping into elementary school territory?

Yeah, I'm done. As I said to Sonofamechanic above, if you don't get it any now, you're never going to get it. Unfortunately you are just not there mentally. Dialogue with you is like trying to SAT tutor a kid who skipped grades 7 to 11. He is simply not equipped. Yet somehow he is convinced he is college material. You are a total farce.

Maybe check out some adult re-education courses on www.coursera.org. Since it's a robot taught web course with no human behind it, it will have infinite patience with you, unlike me. Good luck. You're a chemist? Do us all a favor and stay with chemistry.
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Old 10-06-22, 10:57 AM
  #100  
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Originally Posted by Yan
Cyccommute remember just enough physics vocabulary from his school days to fake an imitation of understanding, but he forgot all the rules of how the words are put together. The result is a total clusterf***. He's like a kid who remembers + - × ÷ but forgot about order of operations. Here is a case of knowing 50% being worse than knowing nothing at all. At least if you know nothing then you know you know nothing. When you know just barely enough to cause you to falsely believe that you know, but in reality you actually don't know... this is just tragic... Combine that with false confidence... it's game over right there.

I'm not saying he's doing it intentionally. I know he genuinely believes he is right. There are many areas in life where conviction goes a long way. Unfortunately this isn't one of them. There's no real latitude for interpretation in this kind of grad school science. At first I thought he knew the concepts but was just applying vocabulary incorrectly. But at one point I brought up the velodrome example, and when he responded incorrectly I knew immediately that it was the other way around. He knew the vocabulary but didn't understand the concepts. The worst possible combination. Right there I figured he was probably beyond salvage. It's easy to teach A kids because they are stars. It's easy to teach F kids because they know nothing and you simply teach everything from scratch. But when you get to the C and D kids... that's what drives people to quit teaching. There is an insurmountable valley of ghoulish unmalleability here, it's soul crushing to watch let alone participate in.

That's my verdict. Sorry if I offended anyone.
I had a whole semi-insulting series of responses typed out but I’m not going to be as small and petty as you. Let’s stick to the original issue:

Look, I understand what you are trying to say about “converts any lateral force into perfectly straight down force as far as the bike is concerned” and that the forces are balanced. But just because a force is balanced by another force, doesn’t mean the force doesn’t exist. The whole “for every action (force) in nature there is an equal and opposite reaction” means that the force has to be balanced. It it weren’t or if you exceed the force, the bike and rider fly off the corner.

Can you agree that if the bicycle and rider are riding straight down the road, that the bike and rider are experiencing the force of gravity? They aren’t moving up or down but they are still under the influence of the gravitational pull of the earth, right? Because of the way a tensioned spoked wheel is built, the rim right above the contact patch is being deflected upwards by the loading of the bicycle rider and weight, giving the rim a (very) slight flattening at the contact patch.

Now the rider goes into a corner. The friction on the tire keeps the tire from sliding off the corner and the centripetal force pulls the wheel around the corner. The bike leans over because of the lateral force on the wheel. Like riding in a straight line, the forces are balanced but the forces are still there. At the contact patch, the slight flattening of the rim is now at an angle to the ground and turns into a slight bending of the rim upward. The bicycle wheel being a tensioned structure isn’t rigid like other wheels with rigid spokes (or rigid structure). In a rigid wheel, the tire does the deflection. To be clear, the bicycle tire also deflects some but the rim isn’t rigidly attached to the spokes and can this bend as well. The whole wheel doesn’t bend. Only a very small section at the contact patch will experience bending.

To be clear, this bending isn’t usually enough to cause the rim to permanently deform. If the spokes of the wheel are over tensioned and the wheel experiences enough force, it could go into the sinusoidal wave form we call a “taco” but most of the time it doesn’t.

And where the hell did you bring up a velodrome example?
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