Wikipedia:Good article reassessment/Bicycle and motorcycle dynamics/1

Bicycle and motorcycle dynamics

Article (edit | visual edit | history) · Article talk (edit | history) · Watch • Watch article reassessment page • GAN review not found

Result: No action. Issues have been raised , the article has been improved, and concrete concerns appear to have been addressed. No one seems to be pressing the case that this article does not meet the criteria. If any editor wishes to make such a case, a new reassessment can be opened. Geometry guy 16:26, 6 June 2009 (UTC)

Reassessment discussion and general comments

I am nominating this for review again. See last review. This article needs a LOT more work to make GA level.

Yay! Finally some feedback we can sink our teeth into. Please ignore any defensive attitude I might display. I will try to keep it in check. -AndrewDressel (talk) 12:44, 12 May 2009 (UTC)

I would suggest that the article is more on par with B class articles such as Bird_flight and of significantly lower quality than Centrifugal force (rotating reference frame), another B class article.

Hmmm. Have you read Talk:Centrifugal force (rotating reference frame) lately? There are major arguments about whether the article should even exist. Bicycle and motorcycle dynamics has been relatively stable for years. -AndrewDressel (talk) 12:44, 12 May 2009 (UTC)

CF is a better article, which is still B class, has a hell of a lot of traffic, and a hell of a lot of quacks. Secondly, I cannot find any discussion of requeuts that the page be removed, or that its content be removed, though there are authors suggesting moves or mergers. The article was relatively stable until major work in the past few weeks. User A1 (talk) 15:09, 12 May 2009 (UTC)

Comment. It is completely ridiculous to have three separate articles about the same subject, and it really constitutes a three-way wp:content fork. One article says there isn't really a force, one says it is a fictitious force, and the third says it is really a centripetal force. Make up your mind and pick one name for the article, please, not three articles. Hint: Don't call it centrifugal force - there is no such thing, and please lose the hatnote "For the general subject of centrifugal force, see Centrifugal force (disambiguation)", and especially don't try to make a disambiguation page into an article about the confusion about which of the three content forks to go to. 199.125.109.102 (talk) 04:43, 1 May 2009 (UTC)

Apologies for what seems like a long rant, these are in no particular order, and are somewhat of a stream of conciousness. I also realise I simply say something is wrong, and not neccesarily how to fix it, however I think some of the problems are beyond a simple fix which can be succinctly given:

Overall comments: The article seems to have something of an identity crisis, particularly with regards to the scope of the article. Facts appear to be placed in a disorganised fashion indicative of a large number of small contributors, with limited organisation.

The article has undergone significant reorganization in the two weeks since this comment was posted. Paragraphs have been added that introduce, compare, and contrast lateral and longitudinal dynamics. -AndrewDressel (talk) 14:59, 28 May 2009 (UTC)

Sections appear to discuss important topics in varying detail,

Topics continue to be discussed in the detail commensurate with the available literature. -AndrewDressel (talk) 14:59, 28 May 2009 (UTC)

but fail to give the reader any clear idea of the important features in bicycle dynamics or provide the reader with a clear model of the problems and theories of bicycle dynamics, and provide a dedicated reader with a good concept of the physical phenomena that allow a bicycle to maintain its upright position when being ridden, or indeed when being released for short sections.

While a clear ranking of feature importance may appear in the popular press, I have not seen it in the scientific or academic literature: most likely because it is not possible. The relative importance of any feature varies from bike design to bike design and even with relative rider weight and forward speed for a particular bike design. The article has for a long time explained how balance is possible and tries to give a balanced review of the competing factors that make self-stability possible. -AndrewDressel (talk) 14:59, 28 May 2009 (UTC)

A bike remains upright when it is steered so that the ground reaction forces exactly balance all the other internal and external forces it experiences, such as gravitational if leaning, inertial or centrifugal if in a turn, gyroscopic if being steered, and aerodynamic if in a crosswind.[9] Steering may be supplied by a rider or, under certain circumstances, by the bike itself. This self-stability is generated by a combination of several effects that depend on the geometry, mass distribution, and forward speed of the bike. Tires, suspension, steering damping, and frame flex can also influence it, especially in motorcycles.

I'm sure there is more, but I have said enough I believe to make the case for reassessment. User A1 (talk) 14:54, 11 May 2009 (UTC)

While there are a few concrete improvements that can be made, as enumerated at the bottom of the discussion about this article, many of the points made below turn out to fall into one of these categories:

• are perhaps overstated or refer to only a single instance:

Many sections include single sentence paragraphs (e.g. "External forces")

Not counting single sentences that precede lists, there are 5 single-sentence paragraphs out of about 100 paragraphs. There is not even one single-sentence paragraph in the "External forces" section, nor has there been since the last GA review. All 5 existing single-sentence paragraphs have since been combined with existing paragraphs.

Article does not consistently use en/UK versus en/US (behavior/behaviour) etc

Exactly one instance of non en/US spelling (behaviour) has been found. It has now been corrected.

Multiple wikilinks are made on a regular basis or are not linked in their first instance. (gyroscope, touring, precess(ion), handlebar, gravity)

• Gyroscopic effects is mentioned twice in the same sentence in the lede. The second instance is linked. The first instance was linked in the version dated May 9.
• Touring is linked in its first instance, in the section on center of mass location. This has not changed since May 9.
• Precession is linked and italicized in its first instance, in the sentence introducing the term. This has not changed since May 9.
• Handlebar is not linked until it is included in a list of key components made of carbon fiber to reduce vibration. This has not changed since May 9.
• Gravity is linked in its first instance, in the lede, under the name of gravitational forces. This has not changed since May 9.

• are contradictory:

This would be more useful if, for example, an equation was given that relates the braking force to the results of braking

Mathematical models could be condensed into "theory" section. Currently mathematics is scattered across different aspects of theory and in theory section.

• seem to be refuted by the text of the current article:

Article fails to make clear the distinction between the action of a controller (rider) versus the inherent stability of the bicycle (system stability) in the stabilisation of the system.

The article already says however, even without self-stability a bike may be ridden by steering it to keep it over its wheels. That seems to separate them.

Article mixes up stability of the bicycle and stability of failure modes (see capsize section). This is a nomenclature issue.

The article already says because the capsize instability is so slow, on the order of seconds, it is easy for the rider to control, and is actually used by the rider to initiate the lean necessary for a turn. That seems to separate them.

• are vague or only potentially problems

Several external links may violate WP:EL#Rich_media

What is the policy on internal cross referencing in articles? This article does it on a few occasions.

Unusual formatting is present in the section on Eigenvalues.

• are looking for simple answers when they do not exist

Article makes initially is unclear as to the effect of gyroscopic action in stability, ascribing it as a possible effect then states that it is possible to ride the bicycle without gyroscopic effects.

Yes, gyroscopic effects influence handling and self-stability and gyroscopic effects are not necessary in order for a bike to be ridable.

Article at times makes no sense A rider can have the opposite impression of a bike when it is stationary. (before and after have non-contradictory statements about the stability of inverted pendulums)

Yes, a bike with a high center of mass will be easier to ride, and a bike with a high center of mass may require more effort to balance when stationary.

Is the trail what provides the decreased turning radius instability, or is it the tire's contact patch?

Both trail and the front tire contact patch can contribute to decreasing turn radius.

Obviously, the article is not perfect, there is always room for improvement, but I do not see any clear violations of the good article criteria. -AndrewDressel (talk) 14:18, 13 May 2009 (UTC)

• Comments. Although opened as a community GAR, so far this has really been an individual reassessment by the nominator, and some additional input from other reviewers would be helpful below, as there do seem to be some GA issues. On a cursory reading, the article appears to be rather undercited. I've added some tags to the History section. For the rest, see the Scientific citation guidelines: in particular, citation at the beginning of each section to authoritative secondary sources is useful even for uncontroversial scientific knowledge. Also, the article uses a fair amount of primary source material (original articles): care is needed here to distinguish between attributing an idea and citing it. If a theory was developed by Prof Clever, then it is preferable to cite a secondary source by Dr. A.N. Other (e.g. a textbook) which describes the theory and attributes it to Prof Clever, than only to cite Prof Clever's original article.

I agree with the concerns raised about the stubby paragraphs. Another GA style issue which I spotted is that the lead doesn't adequately summarize the article. Geometry guy 13:27, 16 May 2009 (UTC)

Cool. That's something I can work on. -AndrewDressel (talk) 13:55, 18 May 2009 (UTC)

The lede has expanded from 226 to 372 words: a 65% increase. -AndrewDressel (talk) 15:04, 28 May 2009 (UTC)

Details

Technical content

Stoppies, wheelies, and endos

• Several sections seem to simply define bicycling stunt manoeuvres, rather than the dynamical aspects of such manoeuvres. Particular examples include the braking sections "stoppies" "wheelies" "endo"s

The paragraph immediately before the stoppie picture says "the front wheel often can generate enough stopping force to flip the rider and bike over the front wheel. This is called a stoppie..." -AndrewDressel (talk) 12:44, 12 May 2009 (UTC)

• But fails to mention anything but the simple fact. This would be more useful if, for example, an equation was given that relates the braking force to the results of braking, such as this effect that at high dv/dt owing to the front of the vehicle causes a rotation about the axis of the front wheel, in some form of hinge-like m phenomena to the reader. User A1 (talk) 15:09, 12 May 2009 (UTC)

Do you mean like this, from the following paragraph?

Therefore, if

$\mu {\frac {h}{L}}\geq {\frac {1}{2}}$

then the normal force of the rear wheel will be zero (at which point the equation no longer applies) and the bike will begin to flip forward over the front wheel. -AndrewDressel (talk) 18:17, 12 May 2009 (UTC)

• Yes, the article should mention wheelies. Now it does, briefly. -AndrewDressel (talk) 12:44, 12 May 2009 (UTC)

Math and theory

• Mathematical models could be condensed into "theory" section. Currently mathematics is scattered across different aspects of theory and in theory section

Does this mean take the equations out of the braking section? -AndrewDressel (talk) 03:31, 13 May 2009 (UTC)

Gyroscopic effects

• Article makes initially is unclear as to the effect of gyroscopic action in stability, ascribing it as a possible effect then states that it is possible to ride the bicycle without gyroscopic effects. I have read the linked PDF "Stability of a Bicycle", Physics today, which seems to indicate that the gyroscopic effect is negligible. Do other literature sources agree? Article seems to say it is non-negligible in motorcycles in "Gyroscopic effect", yet the lede states that this concept has been discredited, furthermore the gyroscope section says "Hence gyroscopic forces do not provide any resistance to tipping". What is the relation between these seemingly counter statements?

A very good point if the article does not make it perfectly clear. What the reader should come away with are these points (in bullets, not prose, for clarity): -AndrewDressel (talk) 19:26, 12 May 2009 (UTC)

• Gyroscopic forces do not provide any resistance to tipping.
• It is possible to ride the bicycle without gyroscopic effects.
• The theory that bikes stay upright because the wheels act like gyroscopes is discredited.
• Gyroscopic effects vary with wheel inertia and rotation rate.
• Gyroscopic effects of the front wheel can assist in the leaning of motorcycles at high speed.
• Gyroscopic effects contribute to, along with trail and other effects, the possibility of self-stability of a bike and how it feels to a rider.

Contradictions

• Article at times makes no sense A rider can have the opposite impression of a bike when it is stationary. (before and after have non-contradictory statements about the stability of inverted pendulums)

This is a sentence out of context. The complete thought is:

Just as a broomstick is easier to balance than a pencil, a tall bike (with a high center of mass) can be easier to balance when ridden than a short one because its lean rate will be slower. A rider can have the opposite impression of a bike when it is stationary. A top-heavy bike can require more effort to keep upright, when stopped in traffic for example, than a bike which is just as tall but with a lower center of mass.

Perhaps a bullet list will make it clearer:

• A high center of mass is easier to balance while riding.
• A high center of mass can require more effort to keep upright while stopped and so give the impression that it is harder to balance.

Switching

• Article seems to switch between types of cycles, making single comments about the effects of each which seem out of place (touring bikes, motor bikes, racing bikes, track bikes particular brands of bikes).

The article is about bikes in general and uses particular types of bikes as example to illustrate points. Which comments are out of place? -AndrewDressel (talk) 12:38, 13 May 2009 (UTC)

• Article seems to switch continually between highly formal physics descriptions and cycling slang ("choppers" "tourers" "eigenvalues"), complex mathematical descriptions and pseudo-mathematics

If there is another, non-slang name for choppers, let's use that. Otherwise, the article will have to refer to them as bikes with very slack head angles or very high rake angles. Also, chopper is the name of the article. I can no longer find and instance of "tourers". -AndrewDressel (talk) 12:38, 13 May 2009 (UTC)

What is "pseudo-mathematics"? -AndrewDressel (talk) 03:34, 13 May 2009 (UTC)

Incompleteness

• Article is incomplete in some respects

Drag is mentioned as an external force, but does not seem to be covered in theory or discussion.

Yes, drag should get more attention. -AndrewDressel (talk) 00:07, 13 May 2009 (UTC) Now its influence on trim is also mentioned. -AndrewDressel (talk) 13:47, 22 May 2009 (UTC)

Trail and tires

• Trail section and tires section overlap or conflict (tires section probably does a better job). Is the trail what provides the decreased turning radius instability, or is it the tire's contact patch?

Tires: generating a torque that tends to turn the front wheel in the direction of the turn, and therefore tends to decrease the turn radius.

Trail:trail causes the front wheel to steer into the direction of a lean, independent of forward speed

Both are true and the relative size of these effects will depend on the parameters of a particular bike. If the article does not already make that clear, then it should. It already says self-stability is generated by a combination of several effects that depend on the geometry, mass distribution, and forward speed of the bike. Tires, suspension, steering damping, and frame flex can also influence it, especially in motorcycles. -AndrewDressel (talk) 18:52, 12 May 2009 (UTC)

• Yes that is what trail is, sure, but what is its role in stability?

It's role in stability might be this, from the second paragraph: The more trail a bike has, the more stable it feels. Bikes with negative trail (where the contact patch is actually in front of where the steering axis intersects the ground), while still ridable, feel very unstable. Bikes with too much trail feel difficult to steer. -AndrewDressel (talk) 03:34, 13 May 2009 (UTC)

Self-stability vs rider control

• Article fails to make clear the distinction between the action of a controller (rider) versus the inherent stability of the bicycle (system stability) in the stabilisation of the system.

The article already says however, even without self-stability a bike may be ridden by steering it to keep it over its wheels. That seems to separate them. -AndrewDressel (talk) 03:38, 13 May 2009 (UTC)

• Article mixes up stability of the bicycle and stability of failure modes (see capsize section). This is a nomenclature issue.

The article already says because the capsize instability is so slow, on the order of seconds, it is easy for the rider to control, and is actually used by the rider to initiate the lean necessary for a turn. That seems to separate them. -AndrewDressel (talk) 03:38, 13 May 2009 (UTC)

Style

Images

• I do not believe that the images are relevant to the topic discussed. Why are there multiple pictures of riders leaning in to turns, doing bicycling stunts etc., when the prose doesn't even discuss this. How does having these pictures enrich the article? We all know what a turn looks like. A schematic of a wheel fork and rotation/lean would be better, if appropriate to the section. Why is Bicycles linked in image at rear wobble section, indeed why is that image even there?

There is one small picture of bicycles in a turn and one small picture of motorcycles in a turn. Is that too many? They enrich the article by showing the activity described. They are as close to the turning section as they fit. I have not seen a good picture to illustrate rear wobble. -AndrewDressel (talk) 12:44, 12 May 2009 (UTC)

Rear wobble could be illustrated via one of those animations (which are quite neat!) . Dynamical effects are best illustrated, well, dynamically User A1 (talk) 15:09, 12 May 2009 (UTC)

• There is also the much more useful animations at the beginning that actualyl illustrate the dynamics of a turn, as opposed to the images shown, which don't really convey information to the reader.

The pictures of a wheelie and a stoppie are about as close to the text that describes the dynamic phenomena as possible. -AndrewDressel (talk) 13:53, 22 May 2009 (UTC)

We all know what a bicycle looks like, yet the bicycle article has a picture of a bicycle. -AndrewDressel (talk) 14:06, 12 May 2009 (UTC)

• It has also has good pictures of bicycles, with markings as to the dynamical aspects thereupon, eg the penny-farthing cycle (although this is an unusual configuration). This image conveys little information that is not conveyed in words. User A1 (talk) 15:09, 12 May 2009 (UTC)

Sections have been reorganized and now the picture of bicycles leaning in a turn is no where near the section on rear wobble. -AndrewDressel (talk) 13:53, 22 May 2009 (UTC)

Chunkiness

• Article is overly broken up leading to a very long table of contents. Many sections have one or two sentences.

Seriously, exactly how many sections have one sentence? -AndrewDressel (talk) 03:40, 13 May 2009 (UTC)

• Many sections include single sentence paragraphs (e.g. "External forces")

There is not one single-sentence paragraph in the "External forces" section. -AndrewDressel (talk) 14:06, 12 May 2009 (UTC)

OK, but there are in other sections. Counts: In "External forces" 3 lots of 2 sentences and 2 lots of 3. Hardly "well written prose". User A1 (talk) 15:09, 12 May 2009 (UTC)

There were exactly 5 instances of single-sentence paragraphs. Now there are none. -AndrewDressel (talk) 22:50, 22 May 2009 (UTC)

• Experimentation section is simply a list.

So are the "See also", "Research centers", and "External reading" sections. Sometimes a list is best. -AndrewDressel (talk) 12:44, 12 May 2009 (UTC)

See also, and external reading are recommended per WP:MOS#Section management. Other list sections are not. MOS suggests avoiding lists where prose suits. See Wikipedia:Guide_to_writing_better_articles#Paragraphs. User A1 (talk) 15:09, 12 May 2009 (UTC)

I believe prose would not suit this section. It is simply a list of key experiments performed. There is nothing to gain and clarity to lose by converting it to prose. As Wikipedia:Embedded_list explains "In some cases, a list style may be preferable to a long sequence within a sentence." -AndrewDressel (talk) 22:50, 22 May 2009 (UTC)

History

• History section seems to indicate that a two year old paper is somehow canonical? Unless this is term is referring to the form of the equations, which is not relevant as a reader capable of correctly interpreting the equations could be presumed to transform the equation set to whatever form is needed, this is unnecessary.

It is how the paper describes what it presents. -AndrewDressel (talk) 14:06, 12 May 2009 (UTC)

Right, but there are a lot of papers out there with a lot of information. Including irrelevant information is not what should be done User A1 (talk) 15:09, 12 May 2009 (UTC)

I suggest reading the paper before passing judgment. A url is provided in the reference. -AndrewDressel (talk) 23:08, 22 May 2009 (UTC)

• History section could use more references, indeed the beginning is entirely unreferenced. If you discount the above reference, the section has only a single reference.

By all means, find more, or request citations for particular statements. -AndrewDressel (talk) 14:06, 12 May 2009 (UTC) There are now nine different references to 5 separate sources. -AndrewDressel (talk) 23:08, 22 May 2009 (UTC)

• Why in goodness sakes is "royal society..." wikilinked. Please use in-line citations if the paper is suitable.

To illustrate the veracity of its contents. It is a prestigious journal. -AndrewDressel (talk) 14:06, 12 May 2009 (UTC)

The article is not about the prestige of any given journal, citations should be given inline using cite tags per WP:CITE. Linking, and mentioning the publication is superfluous and detracts from article quality. Indeed this slides in the direction of WP:VANITY for the paper. User A1 (talk)

The article is about a relatively obscure field with a long but spotty history. To be published in a prestigious journal is the current culmination of that history and is as big a fact as any other in the history section. Physics Today is wikilinked for similar reasons. -AndrewDressel (talk) 23:08, 22 May 2009 (UTC)

Useless facts

• Article includes many useless facts and comments: There is also a gravitational attraction between each component, but this is minuscule compared to all the other forces involved and can be ignored.also Where there is no external influence, such as an opportune side wind to create the force necessary to lean the bike

This is also sometimes called "completeness". -AndrewDressel (talk) 14:06, 12 May 2009 (UTC)

• I claim that including such information for "completeness" is a mistake in writing articles, and stems from one of two situations. Firstly not including information in a position where it connects to other information in appropriate context (disorganised information), and in the second situation a failure of the article to define its scope and cover this scope in an in depth manner (detracting information) as required for a GA. User A1 (talk) 15:09, 12 May 2009 (UTC)

Anyway, the first offending sentence was probably inserted in a misguided attempt to make sure there were no single-sentence paragraphs and is now long gone. The second sentence arose from talk page discussion with other editors who insisted that they could lean a bike simply by leaning their body. It attempts emphasize the impossibility of leaning the combined center of mass without external forces. One example of an external force is as good and arbitrary as another. -AndrewDressel (talk) 23:19, 22 May 2009 (UTC)

• Random comments are dispersed without context throughout he article "Finally, tire inflation pressures are important variables in the behavior of a motorcycle at high speeds."

Single instance corrected. Sentence about tire pressure moved to section on tires and combined with an existing paragraph.

Language

• Article does not consistently use en/UK versus en/US (behavior/behaviour) etc

The article definitely should use one spelling. -AndrewDressel (talk) 12:41, 13 May 2009 (UTC)

Exactly one instance of non en/US spelling (behaviour) has been found and corrected. -AndrewDressel (talk) 13:45, 13 May 2009 (UTC)

Policy violations

External links

• Several external links may violate WP:EL#Rich_media

• Section "Other hypotheses" has links to external sources, and it is unclear if the article is criticising these source or directing the reader to them.

The article currently states While it is an observable fact that bikes can be ridden even when the gyroscopic effects of their wheels are canceled out, the hypothesis that the gyroscopic effects of the wheels are what keep a bike upright is common in print and online. Examples in print: ... And online: ... How can we make it more clear that these are examples of the discredited hypothesis? -AndrewDressel (talk) 13:59, 13 May 2009 (UTC)

In the past, other reviewers have objected to nonNPOV of alternate wordings. -AndrewDressel (talk) 21:17, 23 May 2009 (UTC)

No, I don't agree that simply deleting the list is helpful. -AndrewDressel (talk) 19:29, 23 May 2009 (UTC)

1. According to Wikipedia:Embedded list, "embedded lists should be used only when appropriate", which I believe is the case here, and "in some cases, a list style may be preferable to a long sequence within a sentence."
2. According to WP:EL, links to be considered include "sites which fail to meet criteria for reliable sources yet still contain information about the subject of the article from knowledgeable sources." All the sites listed do, or at least did at the time they were added, contain information about the subject of the article from knowledgeable sources. If one does not or no longer does, that is a separate matter solved simply by correcting or removing the individual link.

• Article seems to include vague advertising for bike styles, without indicating why that information is in the section. (Trail section)

The article now explains However, these ranges are not hard and fast. For example, LeMond Racing Cycles offers,[19] both with forks that have 45 mm of offset or rake and the same size wheels: -AndrewDressel (talk) 23:10, 22 May 2009 (UTC)

Wikilinks

• Multiple wikilinks are made on a regular basis or are not linked in their first instance. (gyroscope, touring, precess(ion), handlebar, gravity)

• Gyroscopic effects is mentioned twice in the same sentence in the lede. The second instance is linked. The first instance was linked in the version dated May 9.
• Touring is linked in its first instance, in the section on center of mass location. The first instance was linked in the version dated May 9.
• Precession is linked in its first instance, in the sentence introducing the term. The first instance was linked in the version dated May 9.
• Handlebar is not linked until it is included in a list of key components made of carbon fiber to reduce vibration. This has not changed since May 9.
• Gravity is linked in its first instance, in the lede, under the name of gravitational forces. This has not changed since May 9.

• The article's wikilinks require revamping, as sometimes complex concepts such as control are unlinked, yet straightforward terms such as "motorcycle racing" and "racks" are linked.

Control is now mentioned in lede with wikilink. -AndrewDressel (talk) 13:21, 22 May 2009 (UTC)

• What is the policy on internal cross referencing in articles? This article does it on a few occasions.

What does "internal cross referencing" mean? -AndrewDressel (talk) 14:06, 12 May 2009 (UTC)

• Internal cross references are where you say as mentioned above#Where_it_was_mentioned and link to the current article at the same time. I am not familiar with the policy on this, but nor have I seen this in general use. User A1 (talk) 15:09, 12 May 2009 (UTC)

I can find no mention of any policy either. The article is big and the content is interconnected by nature. I find internal cross referencing helpful. -AndrewDressel (talk) 13:53, 13 May 2009 (UTC)

Formating and display problems

• Article has some display problems. Equations occasionally appear on top of images (1280*1024, firefox 3.0.6), text behind images etc.

I see no display problems with Windows Internet Explorer version 7.0.5730.11 at 1600*1200. -AndrewDressel (talk) 14:06, 12 May 2009 (UTC)

This does not refute my statement. Article should be accessible to as many users as possible. Firefox is a browser with a not inconsiderable user base, and 1280*1024 is a fairly standard resolution. I have no idea *why* this is happening, but I assure you it is. User A1 (talk) 15:09, 12 May 2009 (UTC)

I do not mean to refute your statement. I have no doubt that it is true. I am merely adding another detail that might be helpful to whomever tries to fix the problem. Clearly, finding and fixing it might be harder for a Windows Internet Explorer user with 1600*1200 resolution. Probably someone with firefox 3.0.6 will have to look into it. -AndrewDressel (talk) 18:52, 12 May 2009 (UTC)

I have moved images from the left to the right in the areas that showed formating problems with Google Chrome and Firefox 1.5. Has that fixed the problem on (1280*1024, firefox 3.0.6)? -AndrewDressel (talk) 13:57, 18 May 2009 (UTC)

• Unusual formatting is present in the section on Eigenvalues.

Can you be more specific? What is unusual about it? -AndrewDressel (talk) 00:11, 13 May 2009 (UTC)

Concrete changes to make

• Improve overall organization.

Significant changes made. Dynamics now grouped into lateral and longitudinal, somewhat parallel to external and internal forces, and the difference between them is explained. -AndrewDressel (talk) 18:12, 28 May 2009 (UTC)

• Develop dynamics of stoppies, endos, and wheelies further.

Done. -AndrewDressel (talk) 23:11, 22 May 2009 (UTC)

• Link complex topics such as Control theory in their first instance.

Control theory is now introduced and linked in the lede. -AndrewDressel (talk) 13:43, 22 May 2009 (UTC)

• Discuss influence of drag

Although still brief, the influence of drag on trim is now introduced. -AndrewDressel (talk) 13:43, 22 May 2009 (UTC)

• Discuss wheelies

They are at least now introduced. -AndrewDressel (talk) 18:28, 13 May 2009 (UTC)

• Fill out lede to summarize article more fully.

Several details added along with references. The lede has expanded from 226 to 372 words: a 65% increase. -AndrewDressel (talk) 14:50, 18 May 2009 (UTC)

• Fix display problem with firefox browser

Potentially fixed. Moved images from left to right and everything looks correct in firefox 1.5.0.11, chrome 1.0.154.65, and ie 7.0.5730.11, though some image stacking occurs at high resolution. -AndrewDressel (talk) 17:36, 13 May 2009 (UTC)

• Spell check

Done. One instance of 'behaviour' corrected to 'behavior'. One instance of 'influcence' corrected to 'influence'. One instance of 'a upright' corrected to 'an upright'. -AndrewDressel (talk) 13:47, 13 May 2009 (UTC)

• Eliminate single-sentence paragraphs

Done. Five instances found. All combined into existing paragraphs. -AndrewDressel (talk) 16:51, 13 May 2009 (UTC)

• In order to comply with "Broad in its coverage", add summary sections on suspension and high side dynamics.

Done. Both new section have links to appropriate main articles. -AndrewDressel (talk) 19:06, 3 June 2009 (UTC)

• In order to comply with "Stable: it does not change significantly from day-to-day because of an ongoing edit war or content dispute", resolve issue with roll moment generate by gyroscopic effect when steering front wheel.

Done. Original source double checked. Numbers and conclussion seem reasonable. Details provided on talk page. -AndrewDressel (talk) 19:09, 3 June 2009 (UTC)

Notification of intention to close

• I intend to close this reassessment as No action unless further issues are raised in the next 3 days. A new reassessment can be opened at any time. Geometry guy 20:25, 3 June 2009 (UTC)