Who has posted that and where? You have it the wrong way around again.
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Who has posted that and where? You have it the wrong way around again.
Tom the Engine said:John, I'm not entirely sure what you try to achieve by namedropping keywords from sophomore classes ("free electron model", "black body radiation curves"). It has served me well in the past to consider this a red flag, but I give you the benefit of doubt and assume it was meant to be educational, which I'm sure other forum members might appreciate.ScienceIsCool said:Most metals are good reflectors of low frequency radiation as you say. (free electron model - http://www.colorado.edu/physics/phys1230/phys1230_fa01/topic12.html) But oxides are a different story. Reflectance drops off a cliff at the infrared. http://www.jcse.org/volume3/paper3/v3p3.php
Without knowing the aluminum oxide thickness, there's no way of calculating or modelling how reflective the cassette would be. Note that it's also likely to have a bit of dust and grease which are infrared absorbers.
And if you look at the luminous flux from a car a couple meters away, you'd see that it's unlikely to be a detectable source of infrared reflection (look up black body radiation curves). The biggest culprit will always be the sun. And that would change in intensity from even small shifts in perspective (i.e., as the bike moves).
John Swanson
And I also worked through the (moderately relevant at best) paper you referenced ("The influence of carboxylic acids in sulphuric acid anodising solutions on the corrosion and SCC behaviour of Al-1050") and, again, I hope that you didn't just google a couple of keywords and inserted a link to the first publication that contained an IR reflection spectrum to add authority to your post? Please don't do that. Referencing is not an end in itself.
When I explicitly state that I oversimplify an argument on purpose to make a different point then I mean it that way. I don't make bold claims either. My bigger point is that using a thermal camera in such messy circumstances in very prone to lots of difficulties, reflections being one of those.
I think we agree that this is not a qualitative but a quantitative question with too many unknown parameters just from watching the video. And your argument with the dust on the cassette is certainly true. But it works in both directions. Most bikes probably have a considerable amount of dust there given the dirt roads on Strade Bianche. But when somebody changed the wheel just recently then there is way less dust or none. And the lack of dust film on the cassette would not only increase reflection, compared to other bikes, but also emissivity, which is way more crucial for sure.
There are just so many things that can complicate interpretation. And you have to try to control for them during the measurement or analysis. And if you are not able to then you have to account for them in your reported error bars.
I therefore repeat my central question: Can you state with confidence that this is a sound and precise measurement and what we're seeing is real beyond uncertainty levels in play? I can't.
Tom the Engine said:I therefore repeat my central question: Can you state with confidence that this is a sound and precise measurement and what we're seeing is real beyond uncertainty levels in play? I can't.
Tienus said:Who has posted that and where? You have it the wrong way around again.
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GJB123 said:Tienus said:Who has posted that and where? You have it the wrong way around again.
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Okay that was a fair comment and one I deserved.
Personally I wouldn't say that the documentary has been debunked, but that there is now rightfully so much doubt as to the veracity of the evidence presented that we cannot and should not take the evidence presented at face value and basically should not use it to make a case for motor use by any of the riders featured in the documentary.
Tienus said:Who has posted that and where? You have it the wrong way around again.
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GJB123 said:Personally I wouldn't say that the documentary has been debunked, but that there is now rightfully so much doubt as to the veracity of the evidence presented that we cannot and should not take the evidence presented at face value and basically should not use it to make a case for motor use by any of the riders featured in the documentary.
That's exactly what it does not explain. It's an extremly oversimplified toy-model for metals that gets a couple of good results on a few properties of basic metals but nothing else. In particular it fails to explain why there is anything else than metals let alone describe those different characteristics. You could just as well have cited the classical Drude model. Stop the name-dropping of stuff you once heard of. Or I can do the same, but with something that actually makes sense and I know inside out: Anyone really curious about this should google "Density Functional Theory".ScienceIsCool said:Anyone curious about this should Google "free electron model". It'll explain why some things are shiny and some aren't.
Oh yeah, just look for a graph that has the right labels on its axes and disregard the rest. Because, you know, all those pesky details that surround the experiment (like thickness of the coating) and how they relate to the situation you're interested in are irrelevant. Please.ScienceIsCool said:You can ignore the bulk of it and just look at the graph.
So you say everything is close to a perfect black body. It's painful to read such nonsense.ScienceIsCool said:When it comes to radiating, you can pretty much ignore what the material is. It's dominated by temperature. At close to room temperature, that'll be predominantly in the infrared. Anyone curious about this should Google "black body radiation".
I think I start to see now what's going on: You don't understand how a thermal camera works.ScienceIsCool said:It's also HUGELY unlikely that the reflected source just happened to be the exact intensity that it did.
You're completely missing my point.ScienceIsCool said:FLIR is pretty well understood and has been used as a measurement technique for ages. It's right up there with "can you trust a ruler to measure length"? Yeah. yeah you can.
This question was not directed at you at all. It was meant for every reader.Tienus said:You then followed it up with a technical post with the question in bold: Can you guarantee. I thought that was funny as I just posted that I would not defend it and that I did not discuss the stade 2 video.
I like this careful attitude. But maybe you could apply it a bit more balanced..Tienus said:My point is that we have not seen enough to draw conclusions
To make my point I questioned if you could guarantee who made the images. You cant even though it seems very obvious.
That was neither my claim nor my goal. I just wanted to add another perspective to this discussion.Tienus said:Posters have posted that the stade 2 doc has been thoroughly debunked by your posts.
Yes, apologies, such generalizations are inappropriate.Tienus said:I'm actually alone, posting from my mums attic.Anyway, I'm amazed how you guys seemingly always find a way to make it fit.
No. That's not what I'm doing. I was being accused of grabbing whatever I could find from Google because I don't know what I'm talking about. I'm trying to show that although I'm an idiot, I did study the things I'm talking about and can display a modicum of competency at it. As always, evaluate anything I say based on its own merits. I'm often wrong and/or mistaken and don't mind.King Boonen said:Argument from authority. Bingo!
ScienceIsCool said:No. That's not what I'm doing. I was being accused of grabbing whatever I could find from Google because I don't know what I'm talking about. I'm trying to show that although I'm an idiot, I did study the things I'm talking about and can display a modicum of competency at it. As always, evaluate anything I say based on its own merits. I'm often wrong and/or mistaken and don't mind.King Boonen said:Argument from authority. Bingo!
John Swanson
King Boonen said:ScienceIsCool said:No. That's not what I'm doing. I was being accused of grabbing whatever I could find from Google because I don't know what I'm talking about. I'm trying to show that although I'm an idiot, I did study the things I'm talking about and can display a modicum of competency at it. As always, evaluate anything I say based on its own merits. I'm often wrong and/or mistaken and don't mind.King Boonen said:Argument from authority. Bingo!
John Swanson
It's exactly what you've done. Tom explained exactly why you were wrong and why what you were referencing didn't make sense and you instantly jumped to the argument from authority. If you disagree, then explain why, so far you've just said because. If you have relevant publications feel free to share them.
I really wasn't calling you an idiot or any other personal attack. Respecting people and respecting their arguments is very different and should not be mixed up.ScienceIsCool said:I was being accused of grabbing whatever I could find from Google because I don't know what I'm talking about. I'm trying to show that although I'm an idiot
That's great. But in a discussion there are really only two options: Either you improve your argument or if you're not capable to do that then you acknowledge it. Referring to background, education, past achievements or whatever instead is - apologies but I have to agree with King Boonen - argument from authority.ScienceIsCool said:This is what I studied at the University of British Columbia
I've actually published in the field of optics.
I did study the things I'm talking about and can display a modicum of competency at it
I'm not even concluding anything. And I'm very open to the possibility that it's indeed a motor we're seeing there. Time will tell. But for now I'm not convinced at all that the material presented is of good and reliable quality for a plethora of reasons.ScienceIsCool said:I don't, however, agree with your conclusions
If you don't ignore the consequences of different emissivities again then you'd realize that not all of these objects can be measured accurately at the same time. By design.ScienceIsCool said:The people are the temperature you'd expect. The bikes are the temperature you'd expect. The tires, the cars, the background, the road, etc.
(1) That's not entirely true. Have you actually tried to convince yourself of the opposite before reaching this conclusion? I didn't do a thorough search at all but here are two screenshots with other stuff that looks a bit odd (marked in red boxes: here and here). Nothing spectacularly strange and you could probably come up with possible explanations - but different looking than other shots nonetheless. I'm sure there's more.ScienceIsCool said:One of the biggest clues in that regard is that there aren't any other unexplained anomalies in any of the pictures taken.
Nono, in this analogy we can't take photographs to estimate the dog. We'd have to rely on the value that the kid with the ruler reports to us. That's what corresponds to a measured temperature value.ScienceIsCool said:And yeah, give a ruler to someone and I'm pretty sure they could get a correct estimate of how big a jumping dog is. Especially if they have photographs to analyze. Will it be completely accurate? No.
sniper said:^Fair questions.
Some general comments/thoughts:
1. Beyond or besides being *a joke*, more to the point imo is that the testing is *rigged*.
2. I would indeed argue that the purpose of the bike changes is first and foremost to recharge (at least for Cance 2010 it quite clearly was) and/or to switch from a non-motorized to a motorized bike/wheel.
3. As you allude to, the other thing that might prompt wheel and/or bike changes is weight considerations. Although what/how/why exactly remains guess work.
4. I agree motors will be most useful at the end of the race. If there is any testing at all at the finish, again see under #1.
5. In the context of the Van Aerts rumors it was reported on twitter recently that there has been no, zero, nada, bike testing at any of the pro cyclo cross races post-worlds. Also, the UCI has been in the habit of putting out press releases whenever they tested for bikes. The absence of such press releases in recent months seems to indicate that bike testing has been rare.
I tend to agree that risk of damage to the bike would be the major factor in keeping the bike until necessary.red_flanders said:sniper said:^Fair questions.
Some general comments/thoughts:
1. Beyond or besides being *a joke*, more to the point imo is that the testing is *rigged*.
2. I would indeed argue that the purpose of the bike changes is first and foremost to recharge (at least for Cance 2010 it quite clearly was) and/or to switch from a non-motorized to a motorized bike/wheel.
3. As you allude to, the other thing that might prompt wheel and/or bike changes is weight considerations. Although what/how/why exactly remains guess work.
4. I agree motors will be most useful at the end of the race. If there is any testing at all at the finish, again see under #1.
5. In the context of the Van Aerts rumors it was reported on twitter recently that there has been no, zero, nada, bike testing at any of the pro cyclo cross races post-worlds. Also, the UCI has been in the habit of putting out press releases whenever they tested for bikes. The absence of such press releases in recent months seems to indicate that bike testing has been rare.
Thanks–I think I still have the same questions.
I don't really understand the weight argument with the UCI limit. If one is using a crank or hub motor, and all bikes (motorized and not motorized) are right at the limit, why bother changing? It seems likely that you can put a motor in the bike and be right at the weight limit. No weight advantage in changing to/from a lighter bike, as all bikes must be over the limit. Presumably this equation changes with a wheel motor, but I don't think there is any evidence that the Cancellara or Froome examples are wheel motors.
That leaves the notion that the testing, however it's conducted, happens before the races.
That still leaves one wondering a bit, as I tend to doubt they're examining the EXACT bike, in the hands of the rider, as they approach the start line. Rather they're examining a lot of bikes in the pit area before the race.
So assuming the latter, why not just roll to the start with the motorized bike? Maybe teams are saving the "hot" bike for the last in case there are accidents or mechanicals. That does seem to make sense.
I guess I kind of answered my own question, but would love to hear others' thoughts on when they do testing or any of the rest.
How many times did Greg change his bike back in the day?red_flanders said:One thing I find somewhat puzzling about the speculation here is that there seem to be a couple of arguments which don't reconcile well. The first is that bike changes are potentially indicative of motor-doping, the second being that the UCI testing is fairly obviously a joke.
As individual phenomena, both seem entirely reasonable to accept given what we know. But if we here know the testing is a joke, why would racers bother with bike changes? Certainly the teams/racers know far better than we do what to fear from testers?
On a separate note, why change into a motorized bike before the finish, where the motor would presumably be the most useful? I mean I get it, you coiuld save energy by using a motor early than ditching it before the finish, relying on your own power. But when I think of the classic examples of suspicion like Cancellara at Flanders and Froome on Ventoux, these are finishing efforts. Presumably those riders crossed the line with a motorized bike.
Do the UCI do the testing at the end of races? If yes, why change into a motorized bike? If no, why not just use the motorized bike the whole way? Weight? That doesn't make sense given the UCI limit and how light bikes are now.
Does someone have a good summary of the testing process in terms of when they test bikes? Seems it's before the races, yes? Wouldn't it make more sense to take the podium finishers and the bikes they're using right off the finish line just like drug testing? Or mix it up? A combo of both?
I don't really understand the testing protocol enough to answer my first couple of questions. Would appreciate any insight.
Yep watched Roglic climb like Dan Martin then TT like Tony Martin. When they said he had a big engine they might have been rightsniper said:Agreed, the potential for a mechanical is a good point.
As I posted upthread, when the UCI introduced their I-Pad + software to the press, the argument for why they went with the I-pad and not with infra-red cams was that the I-Pad method was cheap(er) and allowed for a high quantity of testing at as many races from different disciplines as possible.
But in bleak contrast to what they promised the press at that press conference, there has not been a single bike check in cyclo cross post-worlds and, as far as I can tell, there has hardly been any testing at pro tour road races either post-TdF.
Roglic just won the Volta Algarve and it looks like there wasn't any bike testing.
It's piss take.
Semper Fidelis said:How many times did Greg change his bike back in the day?
I think if you think about it ,,,,,,, whats with all the bike changes? Is it a arms race?