Talk:Corvette leaf spring

Changes to illustration descriptions

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The new illustrations are pretty solid. I rewrote some of the descriptions for clarity, but I have a few questions about the original text, and one illustration. In particular: "The next result is the spring force applied to the right side suspension arms are reduced when the left side is compressed. In this way the leaf spring acts exactly like an anti-roll bar. Note that the position of the right wheel is unaffected by the position of the left wheel. Only the right wheel spring rate is affected." http://en.wikipedia.org/wiki/Image:Trans-linked.JPG First, about the graphic: As I understand it, lifting the left wheel would cause an upward force on the right wheel. It probably wouldn't be enough to overcome the pre-tension of the spring in its natural arc (so the right wheel wouldn't necessarily move upward in the graphic), but the force exerted by the right wheel on the ground would lessen. This force should perhaps be indicated in the illustration, because the original text (and my rephrasing) doesn't seem to naturally follow from the illustration. As in, it's not clear that an anti-roll effect is occurring. Similarly, I'm not sure what you mean when you say "the position of the right wheel is unaffected." Is that a reference to the inability of the anti-roll effect to overcome the pre-tension and raise the right wheel? My next question concerns the interaction of rolls bars and spring rates. Are the two independent? Or does the anti-roll effect increase or decrease relative to the position of the wheel opposite the one being compressed? If the right wheel's movement doesn't affect the extent of the anti-roll effect, then the anti-roll effect doesn't change the right wheel's spring rate. But if both wheels can affect the anti-roll rate, then the right side's spring rate would change. Which is it, or have I misunderstood? One more thing that occurs to me: there's a lot of overlap in the section on suspension motion and the anti-roll section. The two need to be integrated at some point. Best, Alexdi (talk) 02:52, 23 March 2008 (UTC) First, you are right, there is a good bit of overlap. The article really could stand another one of your complete rewrite and reshuffle jobs ;). I really have been just a bit too lazy to attack rewriting and organizing the entire thing. Now to your questions. The graphic: You’re interpretation of the picture is basically correct. Normally the spring applies a given force to the suspension arm based on the position of the wheel. It’s easy to see that with the separate springs. At say 50% compression the spring may be pulling the suspension arm down with say 800lbs of force. Remember that thanks to the wheel being further out on the arm than the spring we need more force at the spring pickup than we will get at the wheel. So if the spring applies 800lbs of force to the arm, the wheel will push down with say 650lbs of force. Anyway, with the two separate springs it should also be clear that as the wheel is moved up (suspension compressed) the force will increase (say 900lbs) and the opposite will occur if the wheel is moved down. Now consider the single spring. When both sides move together we see the same relationship. So we would have 800lbs of spring force applied to each lower A arm. When both wheels are pushed up that force might rise to 900lbs to each side. Of course the force will drop if both wheels are pulled down (650lb to each side). As you suspected, things change if only one wheel is moved. So in the case where both wheels are down, we had 800lbs per side. Now if you move up just the left wheel that reduces the force pushing down on the right side. So now the right side would have say 700lbs of spring force even though it never moved. On the other hand the right side will actually see more force for a given amount of movement. So instead of 900lbs as we had before it might see 1000lbs of force. For clarity perhaps some carefully sized arrows would help. I’ll see what I can do. I am more than open to suggestions. You might consider labeling the spring force as you just did in that example, even if the numbers aren't perfectly accurate. To an extent, the graphic is constrained because it's largely to scale, and the S-bend in the actual Corvette spring is far more subtle than makes for good illustration. Recreating Lamm's graphic (which isn't exactly right, but has the right idea) may be worth a go.Alexdi (talk) 06:04, 23 March 2008 (UTC) Second question, the anti-roll bar: The anti-roll bar is mechanically independent of the leaf spring. If the two wheels move together the anti-roll bar applies 0 lbs of force to either side. But if the wheels move separately it will apply equal but opposite forces to each side. So in the above case, when the left wheel is up the roll bar may push down on that wheel (well the suspension anyway) with say 50lbs of force. It will pull up on the other side with the same 50lbs of force. The forces of the roll bar and leaf spring are additive. To be very technical they are scaled additive. So the anti-roll bar may only push/pull with say 50lbs of force but if it applies that force right at the upright then 1 lb of force at the upright is one lb at the tire. Remember that because the leaf spring is connected a bit in from the end of the suspension arm 1 lb at the spring is somewhat less than 1 lb at the wheel. But for example sake, yes, they just add to each other. The mental block I was running into.. let's see if I can explain this. Let's assume the left wheel is shifted up and there's an S-bend creating an anti-roll effect of 50 lbs. Let's also assume that at rest, the leaf spring was exerting 700 lbs on the right A-arm, and that the spring rate is 100 lbs/inch. So, the right A-arm doesn't move at all, but the downward force it exerts is now 650 lbs. Now, say the right A-arm moves up two inches. The left wheel is still compressed as it was initially. If the anti-roll force doesn't change, then the downward force on the right A-Arm is 650 lbs + 100 * 2 inches = 850 lbs. If that's the case, then the spring rate hasn't changed; it's still 100 lbs/inch, but you're just subtracting a fixed quantity to accommodate for the anti-roll effect. I may just be overthinking this.. Alexdi (talk) 06:04, 23 March 2008 (UTC) Keep up the edits, I think you do a good job of clarifying many of the points.--Springee (talk) 04:10, 23 March 2008 (UTC) You made a quick revert I'm not sure I agree with here: "This is basically how the leaf spring works on the rear suspension of the C2, C3 and C4 Corvettes where the leaf spring was rigidly mounted at its center to the chassis." While this is true, the graphic doesn't reflect the actual configuration of those cars. I think it's important to distinguish that the *effect* is the same, but also that the graphic doesn't exactly duplicate the C2/3/4 suspension geometry. Alexdi (talk) 06:04, 23 March 2008 (UTC) If you think the language is confusing please make the appropriate changes. I've added some additional pictures of the spring in flex with some force values. The values are fictitious but should get the point across. Also, not that I expect anyone to notice but the springs are shown with circular arcs. I do not know what actual shape the real spring would form as they are not simple beams in cross section and if they were they would not form circular arcs.

Query from Autostream, and a response

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I've noticed you are quite knowlegdable on this subject. So i ask for your help. I have added a point to the disadvantages section citing a motor trend article saying leafs adversly affect the ride/handling because it causes the rear to behave like a rigid axle since it connects both wheels. But one editor who seems to 'own' the article says that he disagrees and so he constantly deletes this post and any other. Regarding Motor Trend as not 'qualified' because the article had a one word typo. Perhaps you could offer him some type of extra credibility that would help thanks. --Autostream (talk) 07:13, 21 March 2008 (UTC) While I'm not an expert on suspension design, I fear your opponent may be right. Motor Trend is a generalist magazine; it's not appropriate to use a vague quote from them to support a specific technical explanation of crosstalk. I've seen nothing about harmonics in any exploration of the Corvette's leaf springs. That topic was brought up initially in reference to the C3, but I could find no support, so I removed it. Coil springs are substituted primarily to allow greater customization of spring rate, and to separate spring rate and anti-roll rate, not for inherent problems with leafs. See here: http://temp.corvetteforum.net/c4/gcrouse/Suspension/fiberglass_spring.gif http://forums.corvetteforum.com/showthread.php?t=1918713 Both are the most definitive accounts of the Corvette's suspension action that I've seen. Alexdi (talk) 08:28, 21 March 2008 (UTC) Both sources cast serious doubt on Motor Trend. That reference and the corresponding technical point should be removed in absence of specific support. Alexdi (talk) 08:33, 21 March 2008 (UTC) Although I only recently added a log in name, if I'm not mistake Alexdi and I debated the anti-roll point early on in the history of this article. There were the edits in the early June 2006 time frame. As I have logged in from various locations my IP address shows differently. I have reverted the "cross talk" section back as it is factually questionable (and in my opinion largely incorrect) and because it has no references and runs counter to the information in the Lamm article. Thanks for the input Alexdi —Preceding unsigned comment added by Springee (talk • contribs) 12:41, 21 March 2008 (UTC) Harmonics are an inherent trait of all known Leaf springs since they have been used on vehicles. So if this article is so objective and accurate, to which I think its actually unfair and biased, and you think that Corvette leafs are different for some reason, you must provide support. Otherwise any disadvantage of a composite transverse leaf would also be a disadvantage of a Corvette leaf. I wouldn't have a problem if you want the Motor Trend article moved to a different section, but it definitely belongs as its completely relevant. They test cars for a living and you do not, so their word is far more important than yours or any other personal opinions on internet blogs and forums. So I am willing to compromise on this. You should too.--Autostream (talk) 00:23, 22 March 2008 (UTC) Harmonics are inherent in any spring, leaf or otherwise. However, the glass fiber leaf springs have superior internal damping. They also are very short as used on the Corvette. A short beam length means they will have a higher resonant frequency. The frequencies which affect handling are rather low (handling is usually working in wheel rates of ~1 in/sec). That is much lower than the resonant frequency of the leaf springs on the Corvette. I suspect you are confusing the properties of suspensions which use leaf springs as both spring and suspension link with those which use the leaf as a spring only (see the illustrations I added today). The Motor Trend article is an opinion piece. It does not contain fact based information. Note that Alexi agreed that it was not a valid entry into this article. The problems with the article are several. 1. They are wrong about the material used in the spring. It is one thing to claim that the spring is carbon-fiber based in casual conversation. It is quite another to make that sort of factual mistake in something you are using as a technical source. 2. Their claim that the leaf makes the suspension act like a solid axle is untrue. It certainly is not true based on suspension geometry. I think the illustrations I prepared and added today should put that to rest. If they are talking from a total spring rate calculation based on added the force of the spring + the force of the anti-roll bar then their reasoning is suspect as most cars with independent suspensions use anti-roll bars. 3. They did not explain why they think the leaf spring makes the ride bad. I don't think I need to explain that cars with coil sprung independent suspension have also ridden poorly. There is a lot to ride quality and handling. Many factors including dampers, suspension link design, suspension bushings, chassis rigidity, tires, wheel weight etc. Motor Trend offered no explanation why they think the use of the leaf spring as opposed to using something else would result in poor ride. Unless they can provide a cause and effect type analysis the article is opinion (subjective assessment of ride and handling) followed by speculation (what is the cause of the ride and handling). As such it is not fit for inclusion in this entry. I hope the added illustration give me some credibility in the discussion of the subject. I more than welcome you to use those images to explain how the leaf spring would result in worse ride or handling than an otherwise identical car equipped with coil springs.--Springee (talk) 01:15, 22 March 2008 (UTC) After some additional thinking on the subject I thought I would come back to something Autostream said. The comment was, “Harmonics are an inherent trait of all known Leaf springs since they have been used on vehicles.” This may be referring to axle bound in vehicles with leaf sprung live axles. During axle bounce a series of bumps can excite the natural frequency of the rear suspension. The net result is the axle bounces rather than smoothly absorbing the impacts. It may be natural to assume this axle bounce is a trait inherent in leaf sprung suspension because it is exhibited by so many cars that use leaf springs. However, there are some additional items that should be considered before drawing that conclusion. The axle bounce occurs when the bumps hit the natural frequency of the suspension as a system. That is the frequency of the springs plus the weight of the axle. The heavy weight of a live axle lowers the natural frequency of the suspension system. This makes it more likely to resonate at the same frequency as road bumps. Note that it’s the combination of the spring rate and the weight of the axle that lower the frequency to the point that bounce is likely to be an issue. One of the benefits of an independent suspension system is a reduction in unsprung weight. That means for the same spring rate a higher excitation frequency would be needed to create a suspension bounce condition. This makes it less likely that road surface conditions will cause suspension bounce. In this case the bounce is not inherent due to the use of leaf spring but due to the natural frequency of the axle mass – spring combination. --Springee (talk) 04:47, 22 March 2008 (UTC)

The "it's not really independent" claim

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The linked Motortend article (removed 3/19/08) is factually wrong in reference to the leaf springs. First, they are incorrectly referred to as “carbon-fiber”. They are made from glass fibers (fiberglass), not carbon-fiber. Second, the article is correct in that the leaf spring does connect the left and right suspension arms together. It does this in a way that is very similar to an anti-roll bar. The author, who already has made a factual error in the materials used to make the spring, then states that the spring behaves “a bit like a rigid axle.” No further explanation is given in regards to that statement. Well the author is correct in that the motion of the left wheel does affect the right wheel. It affects the total spring rate of the right wheel. If you push up on the left wheel, the spring force on the right wheel is reduced. However, this is exactly what an anti-roll bar does. Most people seem not to understand that point. Now, the other thing people often say is “well it’s not really independent.” That is actually somewhat true. Then again, neither is the suspension on a Miata, Porsche or Ferrari. All three use anti-roll bars. An anti-roll bar is most commonly a combination torsion-beam spring (the longitudinal sections bend, the transverse sections twist). When you push up on the left wheel, the anti-roll bar pushes up on the right side suspension. The total spring rate of the right side (the normal spring + the force of the anti-roll bar) is reduced because the left wheel moved up. That is exactly the same scenario I described with the Corvette’s leaf spring. However, the Corvette suspension is also “independent” as in automotive terms this refers to suspension motion (not forces). When the left wheel moves up, the toe, camber, caster, track, etc of the right wheel are unaffected. The same is true of the Miata, a Ferrari etc. —Preceding unsigned comment added by 68.209.216.200 (talk) 23:44, 19 March 2008 (UTC) Unless Motor Trend publishes a retraction of this article, its meet and exceeds Wikipedia's Verifiability Standard, i.e, from a reliable, published cited source, and should remain. This Motor Trend point has been re-added as your objection here is based on unsourced personal opinion which does not support the 'burden of evidence' for removal as per Wikipedia's Neutrality Standards. Further removal will be considered vandalism under Wikipedia Standard.--Autostream (talk) 01:28, 20 March 2008 (UTC) It is not correct information. 1. The material is factually incorrect. GM and several other sources state that the spring is made from fiberglass, not carbon fiber. That means the article contains a factual error. This alone suggests the author is not qualified to give further opinion on the subject. Second, the live axle comparison is wrong for the reasons stated above, in the article and restated below. The car does have independent suspension. This fact is not in dispute. That means it does not have wheel motion "like a solid axle". This is not an opinion. It is a fact that can be verified by any number of sources including the picture in the entry. The spring does tie the left and right sides of the suspension together like an anti-roll bar. This is not an opinion. This is fact and is referenced in the book by Lamm which was written with help from GM and the engineers who designed the C4 Corvette. Statements as to the Corvette's ride quality are opinions, not fact. Furthermore, the Motor Trend article does not state any causality between the use of the leaf spring and the hard ride. Remember the Volvo 960 Wagon used the same leaf spring setup. Does it have a reputation for a harsh ride or having "live axle like" suspension? —Preceding unsigned comment added by 68.209.216.200 (talk) 03:28, 20 March 2008 (UTC) Please read the reference more carefully. The leaf material is not the disadvantage. Nor is the link design as this article only about the leaf spring part of the Corvette suspension. It is simply about one of the handicaps of using leaf spring on a Corvette for which the Motor Trend article makes a valid point. If you think have a reliable published source about what you wish to say, you should add it and provide a cited link to it as well. However, since Motor Trend is a reliable published and cited source, you have commited Wikipedia vandalism by 'blanking' after you have been warned, according to Wikipedia Rules. Further, you will be blocked should you blank it again.--Autostream (talk) 04:20, 20 March 2008 (UTC) The stated leaf material in the article is wrong. That means the article contains factual errors. As such the rest of the article must be viewed with skepticism. The article does not state how or why they think the use of the leaf spring leads to poor ride or handling. Thus it does not add to the discussion. For that point to be valid it would have to apply to all cars that have used this type of suspension such as the Volvo 960 Wagon and the GM W-Body cars. The MT article is not an engineering piece, it is an opinion piece that doesn't contain any engineering analysis. As such is makes for a poor reference. Please stop with the vandalism claims. I have not vandalized the article. Rather than continuously re-adding this material why not actually make a case for it? Which points do you think I need to add to. Also, before you claim I am vandalizing anything, please note that I am the original author of this article. Much has been edited since I added it to the Corvette section. I am not interested in vandalizing this post in the least. I am interested in making sure the content stays factual and objective (as well as technically correct). —Preceding unsigned comment added by 68.209.216.200 (talk) 04:37, 20 March 2008 (UTC) Motor Trend is a reputable source of expert road testing and you are not. This whole article should be folded into the 'Leaf Spring' article as suggested in the 'delete' section below. You are imposing a bias in this article which is not the scientific way.--Autostream (talk) 09:48, 20 March 2008 (UTC) You have repeatedly said that. I have repeatedly shown why the information contains unsubstantiated opinion as well as factual errors. That means the information is not suitable for publication. By repeatedly posting it you are vandalizing the posting. Please do not post it again until you can account for the factual errors and remove the opinion section. —Preceding unsigned comment added by 68.209.216.200 (talk) 12:48, 20 March 2008 (UTC) Handling and ride is about feel. Motor Trend feels that the Corvette leaf spring provides adverse handling feel which is why it belongs in this article. If you find a professional cited publication that feels otherwise, you should add that as well. The scientific way is to present all valid professional points and allow the viewer to make his/her own judgements. User 68.209.216.200 from Nashville, Tennessee is censoring, a.k.a 'blanking' and has now violated Wikipedia's Neutrality Standard and Verifiability Standard. Blanking a professional cited source based on your conflicting personal opinion is in violation of Wikipedia's No Original Research Standard. Further, you have used your 'friend' to evade Wikipedia's Vandal Blocking Routine which is deliberate and blatant vandalism and severely violates Wikipedia's policies. You have been warned 4 times and you have now been reported to Wikipedia:Administrator Intervention Against Vandalism Department.--Autostream (talk) 00:46, 21 March 2008 (UTC) 1. You have admitted that the information from MT is subjective, not objective thus it isn't appropriate for this article. 2. I have more than once explained why the OPINION of the Motor Trend writer is wrong. I have given evidence of factual errors in the linked MT article. I have given a technical explanation why their "like a solid axle" comment is mechanically incorrect. YOU have not countered any of those arguments. 3. The material you are adding is inappropriate because it is an opinion, it is not factual. MT does not offer an explanation WHY they THINK the leaf spring is the source of the Corvette's ride and handling issues. Without that connection it is nothing but OPINION regardless of source. You also have not added any connection/explanation. That means you are adding this information because it supports an OPINION which you have. It is not factually consistent with the rest of the article. 4. I am restoring the entry to the condition it was in before you added the factually inaccurate MT opinion piece. Similar claims have previously been added and subsequently removed from this article. By repeatedly adding an opinion to the entry you are vandalizing it. I am not using “my friend” to avoid anything. “My friend” is a work account. Again, I am the article’s original author. I am not vandalizing it. —Preceding unsigned comment added by 71.228.220.51 (talk) 01:41, 21 March 2008 (UTC) To prevent concerns about my unsigned editing I have signed up an account (formerly 68.209.216.200 as well as 71.228.220.51). I have been accused on vandalism for repeatedly deleting a section from this article which refers to an opinion piece written by Motor Trend. My reasons have been listed above. In brief, the article in an opinion piece. The article contains factual errors that are not in dispute. The article contains statements suggesting causality without providing a technical explanation/justification of the claim. The article is not, nor does it claim to be a technical assessment. Given these issues with the article I have removed it. Please note that similar subjective content has been removed from this entry in the past. The removal of the entry in question should not be considered vandalism. Per the Wikipedia page on vandalism this should be considered a good faith edit. —Preceding unsigned comment added by Springee (talk • contribs) 04:13, 21 March 2008 (UTC) As you know Springee's reasons for censoring me are that the article may contain a one word typo and that there isnt a 'good enough explanation' as to why the magazine author(s) feels the way they do. Springs have a huge impact on handling and ride. Two aspects which are inherently subjective; they cannot be quantified with figures. Hence any article on the matter must be subjective. Motor Trend magazine is a hugely credible source on all topics automotive. And the only source to counter them in this Wikipedia article is one man's unprofessional and personal opinion. Deleting a credible point of view is not the scientific way. I feel this goes against the foundation of learning and knowledge, not to mention Wikipedia's credibility and goals. Any encyclopedia is but a branch of learning, and learning is the product of education. We must present all legitimate and professional subjective and objective viewpoints of a subject to allow the reader to make his/her own judgements. Springee claims to be one of the original writers of this piece. One cannot note that it is biased in favor of the Corvette leaf spring. Reading it impartially gives me the sense of propaganda. Something that others users have noted as well at the bottom of the discussion page. I ask that other allow this key knowledge point to flow freely to all on the internet. Thank you --Autostream (talk) 06:58, 21 March 2008 (UTC) The article contains more than a single slip of phrasing. I have repeatedly explained the issue which you have not addressed. I don’t believe, and this is my view only, that you will find Motor Trend to be experts on technical automotive subjects. If we were talking about Racecar Engineering Magazine I would agree. I’m not sure you have any evidence to say my opinion is “unprofessional”. So fact by fact explanation why I was wrong might be more appropriate rather than an accusation. It is not my intent to argue or upset, only to keep this article as fact based and when sources aren’t readily available, reason/explanation based as possible. --Springee (talk) 12:49, 21 March 2008 (UTC) You are censoring based on contention. And that is a clear violation of Wikipedia. You will be blocked if you continue. I am willing to put the relevant and professional Motor Trend article in another section as a compromise under Wikipedia good faith. See above section for more info.--Autostream (talk) 00:34, 22 March 2008 (UTC) No, I am removing an article that contains know factual errors, contains speculation with out explanation, and contains opinion. I would say the article is better suited for a general discussion of the Corvette because it contains almost no information regarding the technical details of the suspension. However, the subjective ride and handling information may be relevant to the general Corvette entry. This entry should be reserved for only a technical discussion. Keep in mind that with changes to just about any car, including the Corvette, I can make it ride nicely or poorly, handle well or poorly while still being able to say it has the same suspension. --Springee (talk) 01:21, 22 March 2008 (UTC) I would suggest you leave the MT information in the discussion section for others to review before adding it to the general topic. Add a new section to the discussion and let others decide if the content should be added. In fact I will do just that.--Springee (talk) 01:23, 22 March 2008 (UTC)

Corvette Spring Pic

Why was the picture deleted? —Preceding unsigned comment added by 24.126.190.8 (talk) 02:13, 13 November 2007 (UTC)

Coil Over Springs

This section says that people upgrade to Penske springs. Penske makes shocks. What the poster must have meant was that people upgrade to a coilover kits that have Penske shocks because a common kit includes a Penske single adjustable shocks with Hypercoil springs. Leaftye 06:07, 15 December 2006 (UTC)

Quarter Elliptic Spring

There's a line in there about quarter elliptic springs. It was added by an unregistered user. I have no idea if it's right. Please check it, and the article in general, for accuracy if this is your area of expertise. Thanks, Dave Indech 10:50, 8 December 2006 (UTC)

Clarification Needed

Exactly how does a transverse leaf spring also act as an anti-roll bar? If anything, it should actually increase the vehicle's tendency to roll. Think of it this way - If one wheel is pushed up the other end of the spring will want to push the opposite wheel down. This is, of course, assuming that the spring is pivoted and not rigidly mounted at the center to the chassis.

Response

Addressed to an extent. The double mounts are supposed to stop it acting as any kind of bar, but in certain implementations with a chassis that isn't stiff, suspension movement on one side of the car could conceivable affect the other.

The problem is, this isn't really Corvette-specific, and it's largely anecdotal evidence that suggests it could happen with this car. Further, I had trouble deciding if the article should address ONLY the Corvette's implementation, or transverse leafs in general. There is no separate article for transverse leafs. Dave Indech, 5/20

This has been addressed largely to my satisfaction in the most recent revision. Dave Indech, 6/2

Harmonics

I can't provide a source on harmonics, or at least not one specific to leaf springs. I do believe that because of the nature of the mounts and fact that the spring is a solid piece, vibrations of various periods (harmonics) from one side will affect the other. The question is to what extent. If the mounts are so loose that the bar can act in an anti-roll capacity, they're certainly capable of allowing vibration to transmit from one side to the other. The wording I chose in the last revision is suitably noncomittal with respect to the Corvette, but the basic fact is correct, so I think it should still be included.

If you like, you may Google 'harmonics' and provide a counterargument. I'm certainly amendable if it turns out the connection is tenuous. Dave Indech, 6/2

Sorry, I originally posted in the talk section, not this one so I didn't see these posts: Harmonics: Certainly there are harmonics in the springs. This is true of all springs, not just the least springs. However, consider that compared to a coil spring the leaf spring is shorter and stiffer. Both raise the natural frequency of the spring system. The spring is of composite construction. Composite constructions are naturally better damped when compared to homogeneous constructions (metal coil springs). The rubber spring mounts are flexible much like a rubber suspension bushing. They are stiff and don't flex easily. They certainly would damp higher frequency vibrations. Finally, consider that most cars have front and rear anti-roll bars. Those bars are long metal springs. They do tie the two sides of the car together thus left and right are not truly independent. They also could be susceptible to the same vibrations a leaf spring could see.

'Roll Issue'

I don't have to provide a link, I spent a half hour going over this with two mechanical engineers, and you can visualize it yourself. The whole point of the section is that the mount configuration has a HUGE impact on how the leaf spring functions. A loose single mount offers no isolation from one side to the other; the leaf is already pre-tensed, and lifting one side increases the tension further, forcing the other wheel down.

C3 Roll: As a mechanical engineer with almost a decade of experience including suspension design, yes I can see what you are attempting to describe. However, the issue is not significant enough for mention nor is the general principle unique to the leaf spring suspension. In the C3 the spring is mounted to the rear dif housing. You will see more movement of the rear dif housing relative to the chassis that of the spring relative to the dif housing. The amounts of movement you are referring to are small enough to fall in the range of chassis flex. While we can make the argument that everything flexes to some degree under any load the amount of deflection in this case is not significant. As such it may be misleading to mention it in the entry because it suggests an issue that isn’t there in practice.

Further edit: I think I see where the confusion is coming from based on your recent edit. I was considering the C2 and C3 rear suspension to be a single fixed mount. It is actually two closely spaced mounts but the intent is to hold the center of the spring and prevent motion from one side from moving the other. Prior to the wide spacing used on the C4 the spring was not able to provide any anti roll. See the leaf spring article in the external link for more details.

Update

http://www.corvetteforum.net/c3/juliet/bef_springdiff.jpg

This is brief because your edit to this page swallowed mine (or something of that nature), but I discovered this from a 1970 Corvette. I cross-checked through various other sources, and there no was mention of any changes from 1963 to 1970. Prior to '63, the C1 had a solid rear axle. I was working on an incorrect assumption, and I did not consider chassis flex. Corrected, though it may need to be proofed further.

Nurburgring

Funny, both the F430 and newer Lambos are slower on the Nurburgring than the Z06, however the Ford GT is actually faster than the vaunted Z06, 7:42 (as indicated by Octane magazine, 11/05) . CJ DUB 18:26, 15 January 2007 (UTC)

It's no surprise the Z06 is faster than the exotics. The F430 is short on power and torque, and the Lamborghini weighs too much. Nor is it any surprise the GT is faster; it's balanced better, it handles better, and it makes 515 HP at the wheels on a dyno. What is surprising is that the Z06 is less than a second slower. The so-called 'Blue Devil' should be a sight to behold.

Dave Indech 06:31, 7 February 2007 (UTC)

Delete?

Why is this page here? What does it offer that isn't in the general leaf spring article? I'm not so sure that wikipedia should include suspension tuning advice for particular models... 81.178.104.81

A feel good for people who feel people like Jeremy Clarkson were unfair to the car is about it. --220.253.14.72 04:52, 13 September 2007 (UTC)

You are absolutely correct, it should be removed. I added a Motor Trend reference article about the significant disadvantages of the leaf spring in the Corvette and anonymous vandals remove it right away because in 'their' personal opinion, Motor Trend is 'wrong'. --Autostream (talk) 01:32, 20 March 2008 (UTC)

The article provides a useful level of understanding and clarification of the suspension design used on the Corvette. I have repeatedly removed the reference to the MT article because it is an opinion piece. You have cited it to back opinions (ride quality, handling) yet neither you nor the article shows how the use of the leaf spring affects the other. The car may in fact ride badly and handle badly but no evidence was presented illustrating WHY the leaf spring would be to blame. That was part of the reason why it was removed.

It was also removed because it contained two factual errors. The leaf spring is a fiberglass structure, not carbon fiber. Also, the spring is not does not "rigidly" connect the wheels together. The ends of the spring are in fact not rigidly connected to the suspension arms at all. They are connected trough short pull links. Given the errors in the Motor Trend article, all of which can be shown to be incorrect by other sources, the article was removed. Please do not refer to the edits as "vandalism". —Preceding unsigned comment added by 68.209.216.200 (talk) 04:22, 20 March 2008 (UTC)

Additional point under "Disadvantages" based on an article in Motor Trend Magazine

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I would like members to discuss the following entries which have been proposed by another member. These entries would be located in the section listing the disadvantages of the leaf spring suspension as used on the Corvette. The proposed entry is as follows: Ride and Handling; according to Motor Trend magazine (11/07): "[the Corvette C6's transverse leafs] make the rearend behave a bit like a rigid axle. Aftermarket tuners have scrapped them in C5s and C6s for coil-springs" Oscillation: The natural frequency of suspension movement which will setup a harmonic oscillation sweet-spot of wavelength equal to double the distance between the leaf mounts. Certain road surfaces will AMPLIFY the movements and could adversely affect the handling and/or ride. (This is sometimes refered to as 'crosstalk'. See section below for explanation.) With regard to point 1 I do not feel it is an appropriate entry for the follow reasons: The article contains a factual error. It lists the Corvette spring as carbon fiber, not fiberglass. In context of a general discussion that may be an acceptable oversight. In context of a technical article from which technical based conclusion will be drawn that is a significant oversight. The article contains a erroneous description of the function of the leaf suspension. The phrasing in question is "make the rearend behave a bit like a rigid axle." This is not true from a kinematic point of view (see the illustrations in the main article). Also, for this to be a fundamental trait of the leaf spring it must apply to both the rear and front suspension as the Corvette uses leafs at both ends. The article does not state that the front suffers from the same issue. The article offers no explanation of how the leaf spring would be the cause of the behavior in question. As such it does not provide additional technical insight. The article does not mention other factors which could lead to the same suspension behavior. To establish that the leaf springs are the cause of the handling issues identified by the magazine, they should also explain why the choice of damping, tires, geometry, unsprung weight, etc were not responsible for the handling trait. It is worth noting that the first year C6 Z06 was reported to have skittish handling. The second year car was reported to be improved. The corrective action was a change to the dampers. The spring remained unchanged. With regard to point 2. This point must stand on it's own explanative merit as it does not have an outside reference. This point has been previously discussed and removed from the article for lack of supporting evidence. No evidence is available which suggests that the natural frequency of the leaf spring as installed in the Corvette would be at a similar frequency as the chassis or suspension. The most important suspension/wheel travel speeds, that is the vertical speed of the wheel, for handling is in the 1 in/second range (see link below for source). Assuming non-bump suspension travel distances of 0.5-2" this would correspond to a frequency of 0.25-1hz. This would be well below the natural frequency of the leaf spring The cross talk term is vague. It has been acknowledged that the Corvette suspension, along with most other independent suspensions do "communicate" across the chassis. In most cars this is done via the anti-roll bar. In the Corvette it is accomplished via the anti-roll bar as well as the leaf spring. Source for suspension velocities: Damper Fundamentals, Basic Damper Principles --Springee (talk) 01:56, 22 March 2008 (UTC) This Corvette leaf spring article deals with springs on a car. And springs have a huge impact on handling and ride. Two aspects which are inherently subjective; they cannot be quantified with figures. Hence any point referring to ride and/or handling in an article on vehicle springs can only be subjective. Motor Trend magazine is a hugely credible source on all topics automotive. And the only source to counter them in this Wikipedia article is one man's unprofessional and personal opinion. Deleting a credible point of view, which is what Springee has done 6x is not the scientific way. I feel this goes against the foundation of learning and knowledge, not to mention Wikipedia's credibility and goals. Any encyclopedia is but a branch of learning, and learning is the product of education. Shouldn't Wikipedia present all legitimate and professional aspects of a subject to allow the reader to make his/her own judgements? --Autostream (talk) 01:55, 25 March 2008 (UTC) You have made the same points before yet you have not replied to my responses to those exact points. So long as we are talking about wiki rules, the section you added with regards to “Cross Talk” was originally posed on a web forum 3 years ago. You didn't cite that website or the author. I suspect that is against the wiki rules. --Springee (talk) 02:30, 25 March 2008 (UTC)

Third opinion

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Hi. I'm stopping by based on the request on the third opinion noticeboard. I can see why this one has languished a bit there, as the dispute is both complicated and technical. I think it's good to come back to basics here. Anything in Wikipedia must be verifiable. We generally do this through reliable sources, and we strenuously avoid original research. Our basic task here is not to act as experts, but to come together to summarize what experts have said. Where there are multiple schools of thought among experts, we can document that. But where expert opinion is too thin or too muddled to support a clear summary, Wikipedia should generally fall silent. When I look at the article, I am worried that we are deep into the territory of original research. I see a great deal of material in the article, but very few in-line citations. It could be that all of this is well supported in the original sources, in which case we should connect the text to the sources. That's especially the case for sentences with value-laden words, like "superior" or "drawbacks". But if not, we should trim the article back to what reliable sources support. Given that, let's look at the question raised in this section. Regarding point 1, if there is a minor error in an article, that may not compromise its reliability as a source. Even the best of us make small mistakes, and a magazine's production process can introduce errors as well. The other concerns (not justifying opinions fully, not explaining sufficiently) also don't seem like enough on their own. If this is an area where experts can differ, then we should find quotes from experts who do differ, and present both POVs. If this is all we have, then it's down to a question of significance. At least to me as an outsider, the bit about people replacing them sounds significant to me. Ergo, I'd keep it, along with the expert's theory on why, and hope that more material eventually turns up. Regarding point 2, if people cannot verify, then we should take it out. The only plausible exception is things that are both obvious and undisputed. At least to this relative novice, it's far from obvious, and if you two are disputing the content, then it's not undisputed. So I'd say it should be removed until it can be supported by a reference. I hope that helps! William Pietri (talk) 03:03, 29 March 2008 (UTC) Thanks for the 3rd opinion. I would ask you to consider the following: When citing a technical source it we are worried about the details of the information. Getting details wrong is not a big deal if we are using the article in question as proof that the car's handling could be improved. However Autostream is trying to use this article to prove a cause and effect. He is trying to prove that the "spring design" is the cause of "poor handling". In that case all details of the spring are of critical importance. Thus a significant error in the description of the spring is a big deal. The difference between making the spring out of fiberglass vs carbon fiber would be similar to ordering a steak and then writing how great the lamb was. Both are meat but they are very different to those who know care about cooking. To the average reader carbon fiber and fiberglass may be the same but they aren’t to an engineer. This is an article about the engineering of a design thus the articles that support it should at least stand up to a minimal level of technical accuracy. The mistake on spring material means they have started out with an error in describing the very part of the car we care about. The other problem with the article is they do not offer cause and effect. The identified effect is poor handling. I am not disputing this effect. The article author attributes this to the use of a leaf spring in the back of the car. This has three main flaws 1. It doesn’t explain why the front of the car, which also uses a leaf spring, doesn’t exhibit similar problems. 2. It doesn’t explain why other design attributes didn’t cause the problem. In addition to springs, shocks, tires, unsprung weight, suspension geometry, chassis stiffness among other factors play into handling. The MT article didn’t explain why these other items weren’t to blame. I would further this point by adding that when the C6 Z06 was first released it has a reputation for having a skittish rear end (the exact problem described in the MT article). The next year the complaints were addressed not by a change in springs but by a change in dampers. This certainly suggests that things other than the spring could be the cause of handling issues. 3. The article incorrectly associates the use of a leaf spring with a solid axle. The article correctly states that the spring ties the left and right suspension sides together. However, this is not uncommon as all anti-roll bars do the same thing. This is explained in the main wiki entry. The main wiki entry also explains why the motor of one wheel doesn’t affect the motion of the other (ie the suspension is independent). Thus the point should be called into question. In the end the article has two significant errors and lots of speculation without addressing alternative theories for what the authors are feeling. As such I do not believe it offers any technically reliable content for the wiki entry. It is a valid entry into a discussion about Corvette handling but not into a discussion about the characteristics of a leaf spring suspension such as used on the Corvette. As the third opinion I would like to know which of my points you agree or disagree with. --Springee (talk) 15:30, 29 March 2008 (UTC) Sure thing. Taking the same format: The question is whether the error is a shallow one or a deep one. If it's a shallow one, like where the expert thought "X" and wrote "Y", or somebody laying out the magazine changed something from "X" to "Y", then we should ignore it. If it's a deep one, where it really is X and he thought it was Y and based conclusions on that, then we're in harder territory. It's important to remember that we only cover what's verifiable, not what's true. That doesn't mean that we write things that are obviously false, but we do accept that the published experts are the published experts, and we are some amateur scholars on the Internet. Given the details as I understand them, then we should not use the article to claim that the springs are carbon fiber, because we have reliable sources proving otherwise. But as far as their opinions about how they behave, we can definitely say "according to authority A..." and include their opinion. If there is a controversy, then you should find a matching quote and say, "However, authority B says...". Other assertions of observed fact, like the bit about what aftermarket tuners are doing, we should generally accept at face value. Although those are excellent questions, and they are exactly the kind of thing that another expert might write in a rebuttal to their article, worrying about them too much here brings us into the territory of original research. That can be frustrating. There are several topics here that my profession has made me expert in, but I cannot write things I know to be true, because they have not yet been published by reliable sources. If this bothers you too much, you may need to find other places to write, like mailing lists, a blog, or trying to get articles into on-line or paper magazines. But as far as Wikipedia goes, if this one Motor Trend article is all that has been written on this point, and if they have a significant opinion on the topic, we should publish the opinion. So in sum, I'd say that with only one source we're on somewhat thin ground. Quoting the source by name is appropriate, and signals to the reader that a) our sourcing is thin, and b) other views on the topic may exist. If you personally hold a contrary view, then you should be diligent in finding equally reliable sources that hold other POVs, so that you can demonstrate that the experts disagree. If you only find confirming material, then you should update the article to match and just accept that this is one area where you and the experts disagree. Hoping that helps, William Pietri (talk) 17:10, 29 March 2008 (UTC) I see your point about including the point but and pointing out the potential flaws in the point. The problem I have with that is then we end up with a very long entry that may leave the reader more confused that anything. That is why I posted the point in the discussion section where people could read it, read the counter claims and make up their own minds. For instance, we can post the MT claim that the car is skittish due to the spring. I know from my own background that there are many factors that could be at play here. We have the spring rate, we have the fact that the spring connects to both wheels like an anti-roll bar, we have the numerous non-spring factors such as shocks that I have already mentioned. If a speculative point is added to the article we then need to add a lot of counter speculation. That would range from, is MT a technically qualified source of this information (they aren’t Racecar Engineering Magazine or the SAE’s magazine after all), are the facts in the article correct etc? In my last posting I mentioned a Car and Driver review where they stated that changing the shocks improved the skittishness of the rear of the Z06 Corvette. Well that strongly suggests that the skittishness was damper related, not spring related. So I would need to put that in the article as well. Again, in the end we have a long drawn out entry that looses much of its value because it confuses the reader. I would also like to comment on the original content part. I was under the impression that one of the reasons we let so many people edit these postings is because you get a sort of consensus built up. Over time we as a pool come to an agreement and that helps shape the article. Over its life I have contributed quite a bit to this entry. I have tried not to add much in the way of opinion. Much of what I have written and illustrated is based on what Michael Lamm talked about in the article linked to in the wiki. Basically, almost all the content can be traced to that article. The rest is simply illustrating the concept better and explaining (yes, original content) why perceptions don’t apply. While I’m not 100% versed in the rules, I don’t see why original content should be an issue so long as it’s explained and illustrated. --Springee (talk) 17:51, 29 March 2008 (UTC) Again, your knowledge from your own background may be a handicap here as much as a benefit. As an example, compare a modern historian of ancient Greece to somebody who actually lived in ancient Greece. The former will have a much easier time writing a short overview of ancient Greece for a modern general audience than the person who actually lived there. The resident is too close to the subject, has too many opinions, and will have focused much more on some aspects of the topic than others. They will have trouble separating what they know from what the current expert view is. If the situation is confused, then we should explain clearly that it is confused. Perhaps you could take the approach of saying something like, "many question the handling of recent Corvettes, with one suggesting leaf spring issues[1] while another recommend replacing the shocks[2]." But if your main objection is that the published experts are coming to conclusions that you disagree with based on analysis you think they should have approached differently, then their opinion is the one that should win out in the article. Again, [WP:V|verifiability wins over an individual editor's perception of the truth]]. As to originality, all of our content should be original, but for most topics, none of our research should be, because otherwise people can't verify it. If you think any good scholar with a modest understanding of the topic can come in and verify every bit of this article from the sources, then we're good to go. But if they will need a lot of knowledge from your own background, or if people from different backgrounds could reasonably dispute things, then we probably shouldn't have those things in the article. That sort of material and that sort of approach could well be great for a car enthusiast's wiki, but not an encylopedia built on verifiability. I contribute to wikis that are not Wikipedia for precisely this reason. I do agree that the article is long. Not knowing the topic well, I can't say the the right approach, but I'd look first at some way to split it out. Perhaps one that's just about the physics of leaf springs would be good, leaving this one to be just about Corvette leaf springs. Hoping that helps, William Pietri (talk) 19:12, 29 March 2008 (UTC) Perhaps then the entry should be listed in the area covering the anti-roll effect of the spring. The MT article says the handling issue is caused by the leaf spring spanning from side to side. However in the anti-roll section the article explains how the anti-roll affect works (and cites a book on the development of the C4 Corvette as a source) and why connecting the two wheels together is not a bad thing but is in fact a good thing. That would also be a good place to explain why that sort of criticism is short sighted in that it assigns blame without showing that other aspects of the car’s design might be at fault. Regrettably one of the things that I think makes the article pretty good is that it doesn’t say the car does or doesn’t handle well. It tries to be entirely fact and reason based. As Autostream points out, handling is relatively subjective. Adding a discussion of “handling” opens the door to counter claims such as “the car handles well”. I would also point out that Motor Trend is not an engineering magazine. It is one thing for the editors to say, “An engineer at Honda said…”. It is quite another for their generally non-technical editors to pass engineering judgment on a subject. Again, if we were dealing with an actual technical magazine (Racecar Engineering Magazine, Automotive Engineering Magazine) then I would give them the benefit of the doubt. However, I do not want to question the source in the main article. With all this in mind I really do think the article is better without the additional information. As the effect is in question (even by the first editor Autostream contacted) I would say at best it merits discussion in the anti-roll section. I would not post it in the disadvantages section because the information is too vague to provide a good cause and effect explanation.--Springee (talk) 22:06, 29 March 2008 (UTC) We seem to be getting well beyond what a third opinion is supposed to be good for. Unless you have an an expert opinion in a reliable source saying that their criticism is short-sighted, you may not include material like that, even if you are sure you're right. If there are better sources to cite than Motor Trend, then cite them. If Motor Trend is all you have, then that's all you have. Just quote it in a way that readers can make their own judgments. E.g., "Most consumer car reviewers don't like the handling of the 2008 Corvette, with some, including Motor Trend, laying the blame at their choice of leaf spring". Handling is subjective, but we cover many topics that are subjective. We do that by explaining what people say in a way that our readers understand that it is subjective. If the bulk of experts don't like the handling, then say that, and document it. If there are two different schools of thought, say so and document that. But you may not leave out the topic just because you disagree with the sources you have. You should only leave out handling if it is unimportant or if reliable sources don't comment upon it. If you and the other editors here need further help, feel free to ask for another third opinion or file a request for comment. But you folks asked for a third opinion, and now you have one. For now, I'd suggest you work it out amongst yourselves. Thanks, William Pietri (talk) 23:01, 29 March 2008 (UTC) Again, I appreciate your input. As I am quite concerned about adding a speculative source but if the rules say it gets added I will be ok with it so long as the questionable nature of the claim and source are also clear to the reader.--Springee (talk) 23:51, 29 March 2008 (UTC)

Additional "Cross talk" entry

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This entry was removed as it does not contain sufficient technical justification. The material is also covered in other sections of the article. I am placing it here for member review The entry is as follows: CrossTalk General Motors stated that crosstalk is not an issue with the Corvette. Presumably because almost all cars already have a torsion spring (roll bar) between the left and right suspensions. So any issues with cross talk would to some degree be present in conventional systems. This is true to some extent, but they work in entirely different fashions. An anti-roll bar is NOT restrained at the mounting points, so when one wheel moves up, the bar is twisted AND TURNS IN THE MOUNTINGS to impart a force to the other wheel. There is still a harmonic issue but NOW it is at wavelength harmonics of the length of the COMPLETE bar. As it's NOT required to act as a spring, it is VERY stiff and hence has a very HIGH natural frequency beyond the expected movements. The difference being: the rate of change BETWEEN the wheels NOT between wheel and chassis. The spring does not TWIST, it bends. The bend is perpendicular to the mounting points, so it imparts to the other side, but indirectly. For more information, please see the external link to Michael Lamm's book The Newest Corvette, located in the external links below. The information contains technical errors and does not contain sufficient evidence to support the conclusions it states. For this reason I have removed it from the main article and placed it here for member review. My issues with the entry are as follows: "Cross Talk" is not a technical term. It needs a definition with respect to what is happening on a technical level. With out a base definition the phrase should not be used. That anti-roll bars impart a force from one side of a suspension to the other is not in question. The fact that a majority of cars use some sort of spring to connect the left and right wheels together is not in question nor is it a considered to be a negative attribute. An anti-roll bar is constrained by its mounting points. The typical anti-roll bar has both longitudinal sections as well as a lateral section (assuming a simple "U" shaped bar). The longitudinal sections are typically connected to the suspension with short links. The longitudinal sections of the bar are under a bending load. The lateral largely spans the width of the suspension system. It typically has two revolute mount points. These points restrain the bar in displacement but not twist. These mounting points will have some component of friction in their action as they must restrain the anti-roll bar as it is being twisted. As such they must react to the twist loads in the bar. As the anti-roll bar is mounted at some place less than at its ends it would not resonate at a frequency related to its total length. This is actually a good thing as lower oscillatory frequencies are more detrimental to ride and handling (see the discussion section above). The phrase ‘’ The difference being: the rate of change BETWEEN the wheels NOT between wheel and chassis.’’ Requires further explanation. It is not clear what conclusion this phrase is supporting. The leaf springs used on the Corvette is mounted to the chassis at two points. Those points are set up to act as pivots. If one of the two points were removed the leaf spring would be able to pivot in the joint similar to a see-saw. The assertion that the rotational stiffness of the mount points negatively affect the function of the suspension is speculative. It is not supported by the Lamm article or any external links. In this regard the statements regarding the stiffness of the mounts is in error or question. The author has not explained why bending vs twisting is an issue. Many race car anti-roll systems use springs in bending vs twist. The author suggests that because the deflection of the spring is not “direct” it is less effective. This reason for this is not clear. Additionally, a traditional U-shaped beam does not apply force directly. As mentioned above the force starts as a bending/beam load on the longitudinal section of the bar. In the rotational section it load is transmitted as a twist/torsion load in the bar. At the far side the load is changed back into beam loading. No information is provided as to suggest if this is a good or bad thing. I do not feel that the entry in question provides significant insight nor do I feel it has proven to be accurate. For this reason I have moved it to the discussion section for member review. —Preceding unsigned comment added by Springee (talk • contribs) 02:56, 22 March 2008 (UTC)

A message for Autostream

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You have requested I add a number of citations under threat of blanking content. I have added the citations. Note that some of these requested citations were so trivial as for their request to simply be a childish act. For instance, the article stated that the anti-roll effect of the leaf spring was not sufficient to meet the roll requirements GM set for the Corvette. You asked for a citation. Well I would say the fact that GM added an anti-roll bar is pretty clear evidence that they felt the car needed more anti-roll. I apologize for not specifically pointing out where the link says the car has an anti-roll bar. I didn’t realize we needed to go to that level. The article stated that an anti-roll is a type of spring connected between two wheels. I link to an article on handling which states exactly that. Do I need to give a quote in the main article text or should I explain each citation here? Really, this editing war is childish. Someone who commits plagiarism should not be telling others what is OK or not OK on Wikipedia: http://en.wikipedia.org/w/index.php?title=Corvette_leaf_spring&diff=prev&oldid=199780052 http://www.ultimatecarpage.com/forum/302698-post18.html --Springee (talk) 01:54, 3 April 2008 (UTC) This is because you 'choose' to cite the trivial point and not the 'rigid connection' part of the paragraph. I have added another citation so their is no 'confusion'. Further, this whole article is biased with your 'opinions'. When I remove your opinions, you 'undo' my edits inncessantly. Your ownership of this article is making it difficult to keep it neutral. So citing the points I tagged are neccessary to maintain Wiki:NOR standards.--Autostream (talk) 02:01, 5 April 2008 (UTC) Also, what is wrong with folding this entire article in a 'transverse leaf spring' article as there is little difference between the leafs on Corvette's, Volvo 960, GM W's, etc? If they had fact checked the article they wouldn't have said carbon fiber. They also would have used a more accurate description of the suspension's operation. Given that BOTH are wrong the article falls very low on the Wiki credibility scale. Contrary to what you have just said, I have repeatedly cited the rigid connection part as completely flawed. I have included a number of links illustrating exactly what Lamm said. I have included patents that show the non-rigid coupling used in this type of suspension system. The photo of the C5 suspension shows the link passing though the spring to the A-arm. Just in case here is another picture, this time of an leaf spring swap. Hopefully can tell the spring pulls on the tension link when the wheel is compressed. [1] Additional citations move us into the realm of citing the trivial which Wikipedia does not encourage. There are not opinions regarding the mechanical function of the spring or suspension. I did not create this as a separate "Corvette Leaf Spring" article. I added it to the Corvette article. Personally, I think it could be added back into the Corvette entry. --Springee (talk) 04:52, 5 April 2008 (UTC) Autostream, It is your contention that the MT article represents a reliable source. According to Wiki rules of verification, a reference or fact from a reliable source can stand as its own points even if other reliable sources contradict those points. So IF the MT article is considered a reliable source it can be used as evidence of the point you are trying to support, the Corvette has handling problems specifically BECAUSE it uses a leaf spring and NOT because of other design/tuning characteristics. However, if the MT article is considered a Questionable Source it “should only be used in articles about themselves.” That means it can not be used to support claims in other articles. The wiki guidelines state that questionable sources are “those with a poor reputation for fact-checking.” So in context of the MT article, we have two facts as you have pointed out. First is the material claim. We both agree that the MT article incorrectly identified the spring material. Second is the mechanical function of the spring, as you put it, the “’rigid connection’ part of the paragraph.” This has also been shown to be incorrect. The Lamm article does not support that claim, the patents on transverse leaf springs show non-rigid connections, finally, the photos in this link [2] show the front spring has a rubber pad that pushes down on a flat area of the front, lower A-arm. The rear uses a tension link with rubber bushings at either end. As such it is clear that the leaf spring is not rigidly connected to the A-arms. It is clear that the geometric motion of the suspension defined by the A-arms and not by the springs (which would actually create an over constrained kinematic structure). Based on the two factual errors above the article MUST be considered a Questionable Source and per Wiki rules can not be used in support of other claims. —Preceding unsigned comment added by Springee (talk • contribs) 18:53, 5 April 2008 (UTC) I Disagree with all your points as I've said in the current mediation case: 1. We can't be sure that the material is NOT made in part from carbon because we know for a fact that the Corvette leaf spring is indeed a 'composite' of fibers from GM's own press releases on the Cadillac XLR: "Like the Corvette, it uses transversely mounted composite leaf springs front and rear." (If you google this quote, you will find at least ten publications with this exact quote, signifying a press release.) So it is very possible that the leaf is contains fibers of carbon. But either way, the material is NOT in question here. Only the way the part functions. 2. Each 'wheel' is connected to the leaf by a solid bolt with bushing- and the leaf is one solid piece whereas its opposing ends then connects to the 'other' wheel via another solid bolt with bushing. Bolts and bushing is basically how all movable suspension parts are connected in modern cars, and are 'rigid' connections in the accepted sense of the word. Rigid enough that, for example, vibrations could and would be transferable across the leaf from one wheel to the other. This is most likely the theme that Motor Trend was reporting on when they said this about the C6 Corvette, "...they make the [Corvette's] rearend behave a bit like a rigid axle." This is refering to an amateur term called 'Crosstalk'. Springee have 1001 theories about how this could not possibly ever happen in the Corvette, but they are just that: his theories and you can read all of them above. The LAMM article never mentions solid, or rigid, connections. And Springee has previously (but not always) agreed to a crosstalk 'effect' being possible but dismisses it as a feature of any car that has a sway bar. I disagree, one is bending, one is twisting; similar but not the same theory- but either way, sway bar discussions are another matter. More importantly, MT contributes the 'rigid axle' feel specifically to the leafs and NOT the anti-roll bars or shocks or control arms or links or anything else. Coming from a published source that has tested virtually every car in America, I believe its far more than a legitimate POV- which begs inclusion according to Wiki Standards.--Autostream (talk) 23:45, 6 April 2008 (UTC) It is clear based on your edits and your admitted work outside of this site that you are completely biased and not actually interested in anything other than dumping on this site. Either you are playing very dumb or you shouldn’t be producing automotive videos while doing a very bad portrayal of Jeremy Clarkson. One last official response to your points then it's time to leave you because it is clear your purpose on this site is the same as it is on all the Corvette and Viper forums you signed up for, to be a troll. 1. The Liteflex leaf springs are fiberglass as stated in Lamms book and by the manufacture. You have no source for your claim.[3][4]. The manufacture also talks about their use as a stabilizer bar. 2. You clearly do not understand the purpose of a suspension bushing. They are flexible rubber parts that let one part move relative to another.[5] Again, how can you make car videos if you don’t understand this? I posted a link to a site showing how to change the leaf spring with lots of pictures. In no picture do you see the bolt clamping the leaf to the arm. In fact in the front there is not bolt because the spring pushes rather than pulls. 3. “Crosstalk”. Again, you are either playing dumb or really don’t understand suspension. I NEVER said the crosstalk doesn’t happen. In fact it does. It is the exact same crosstalk you get with an anti-roll bar. That is if you push the left wheel up, the right wheel wants to go up. Perhaps this thread will help. Unlike you, Jahan is a suspension engineer and an expert in ride and handling. He agrees with my “crosstalk” explanation. To quote the manufacture, "Multifunctional-LITEFLEX®springs can also be used to perform the function of a stabilizer bar or link, thereby simplifying the suspension design." http://forums.corvetteforum.com/showthread.php?p=1564867869#post1564867869 http://forums.corvetteforum.com/showthread.php?t=1954461&page=3&highlight=Jahan ‘’To 99% of everybody, ride and handling are very subjective things. In reality, those people have no idea what good ride and handling is, because most people have never driven a car that TRULY does both well. Also their perception of a vehicles ride and handling are significantly affected by unrelated things such as noise and interior comfort. In reality, ride and handling can be measured, and under controlled conditions, evaluated in such away that they become more like objective metrics. ‘’ What about this crosstalk stuff? Here is what Jahan said: ‘’ If the spring has any level of isolation that allows movement within its mount, then there is SOME level of cross talk, depending on the rate of the mounts and where they are located. However, this cross talk would have the same effect as the stabilizer bar, simply adding roll stiffness to the suspension. It can't be considered in the same context as a solid axle, in which one wheel's motion is 100% dependent on what the other wheel is doing. This is where many people run into a mental block they can't get past.’’ Note that his explanation is in line with the patent literature I have collected. Did you read any of the patents? You? You didn’t agree or disagree with my cross talk claims. You copy-pasted someone’s post from a web forum and claimed it as your own. So you were guilty of adding uncited, original content AND plagiarism all at the same time. The suspension engineer above had some thoughts on MT’s technical knowledge. ‘’ The first thing most people don't realize is that car mag editors aren't REALLY all that knowledgeable about cars on a technical level. I know several of them and was offered a job as a tech editor at one of the big three mags. So they are prone to all the same biases, pre-conceived notions, and misconceptions that the rest of us are.’’ I will leave you, well at least the other people who might understand this, with one last bit: Carroll Smith, you do know who he is right? He is unquestionably an expert in automotive engineering. ‘’ If I were involved in the design of a new passenger vehicle, however, I would give serious consideration to the use of a transverse composite single leaf spring of unidirectional glass or carbon filament in an epoxy matrix. This would be the lightest practical spring configuration and, although space constraints would seem to limit its use in racing, it should be perfectly feasible on road-going vehicles, from large trucks to small commuter cars. (Since I wrote this paragraph the new-generation Corvette has come out with just such a spring to control its independent suspension systems-at both end of the car.)’’ --Springee (talk) 05:22, 7 April 2008 (UTC) Sorry, unintentional blanking--Springee (talk) 05:10, 7 April 2008 (UTC)

Suggested move

I know this page has been under considerable controvery these days, but I would like to bring up another issue. I think it might be better to move this page to a new title, Transverse leaf spring. While the current article focuses on the Corvette, much of the info is applicable to any vehicle with transverse leaf spring arrangement. It seems a little funny to devote an entire article to the suspension of a single vehicle, it is a little like having a Porsche 911 rear engine layout article. In my opinion corvette specific info should be transfered to the appropriate Corvette page and the article should be made more general regarding the characteristics of transverse leaf springs. Of course mention of the Corvette should be made as it is certainly the most famous user of this suspension arrangement, but I think a lot of the controversy could be reduced if focus was taken away from a specific vehicle. Any thoughts? --Daniel J. Leivick (talk) 04:59, 7 April 2008 (UTC)

I think that would be a good idea. However, if we do that I think we should keep it to later model cars or cars that combine the transverse leaf spring with independent suspension. I don't see a reason to include much older cars like the Model T. Is there a way to maintain the Corvette Leaf Spring title with a redirect so that external links to this page still work?--Springee (talk) 05:13, 7 April 2008 (UTC)

I am glad you are in agreement. Perhaps in order to exclude vehicles like the Model T we could call it Composite Transverse Leaf Spring. A Redirct is obviously a must. --Daniel J. Leivick (talk) 05:33, 7 April 2008 (UTC)

Composite might be OK but that would technically leave out some versions of the C3 Corvette. What about "Modern Transverse Leaf Spring Suspension" or "Independent Transverse Leaf Spring Suspension"? —Preceding unsigned comment added by Springee (talk • contribs) 05:52, 7 April 2008 (UTC)

Hmm... well in that case we could just use the Transerse leaf spring as the title and just touch on the fact that older vehicles used it. That section could later be expanded. Later if the article became too long it could be split, but at this point I don't think we need to have two articles one early and one modern transeverse leaf srping. --Daniel J. Leivick (talk) 05:58, 7 April 2008 (UTC)

That seems like a reasonable way to handle it. Springee (talk) 06:07, 7 April 2008 (UTC)

Daniel, that sounds reasonable to me. I am assuming you would prefer the newly titled article 'Transverse Leaf Spring' to make mention of the makes and models ONLY using TLF's? And then the specifics to go into the Corvette article, in this example? If this is the case, I ask that you draft the two revisions if you would like, and if Springee agrees. This issue is currently reaching conclusion under Mediation Wikipedia:Mediation_Cabal/Cases/2008-03-27_Corvette_leaf_spring and the moderator has concluded thus far that when discussing the 'Performance and Handling consideration" on the modern Corvette, this cited quote must be added: "Ride and Handling: according to an opinion in Motor Trend magazine, the Corvette C6's transverse leafs "make the rearend behave a bit like a rigid axle. Aftermarket tuners have scrapped them in C5s and C6s for coil-springs". - Above quotes are the mediator HAERMO's actual context verbatim. This represents the Mediators proposed solution to our mediation. Of which I will agree to his compromise in all respects.--Autostream (talk) 02:06, 8 April 2008 (UTC)

As the MT article is vehicle specific it may be inappropriate in a general article. Additionally, the factual errors make it a questionable reference.Springee (talk) 03:19, 8 April 2008 (UTC)

The MT article would therefore be appropriate in say the Corvette article when talking specifically about its leaf springs or in a Ride or Handling area. But Springee's objection to alleged factual errors have already been rendered moot by Wiki: 3rd Opinion,[see above] "we do accept that the published experts are the published experts,...Given the details...we should not use the article to claim that the springs are carbon fiber....But as far as their opinions about how they behave, we can definitely quote it in a way that readers can make their own judgments. E.g., "Most consumer car reviewers don't like the handling of the 2008 Corvette, with some, including Motor Trend, laying the blame at their choice of leaf spring".[from user:William Pietri] --Autostream (talk) 04:28, 8 April 2008 (UTC)

• The MT claim would be appropriate in the Corvette Vehicle Wiki as a point of reference with respect to ride and handling. The mechanics of the MT claim (ie how the system functions) qualify as questionable due to the demonstrated factual/technical errors in the article (spring composition and rigid connection). As a questionable source it can only be used in context of discussing what some people perceive. It can not be used to make general statements about the topic.Springee (talk) 04:44, 8 April 2008 (UTC)

---

I'm adding some corrections and clarifications to the above information.

"Most consumer car reviewers don't like the handling of the 2008 Corvette, with some, including Motor Trend, laying the blame at their choice of leaf spring".

Both autostream and I would have to object to this quote because it represents a personal point of view. We would also both expect a citation to justify the "most" term. Autostream has made it very clear that all statements must be carefully cited.

The following text is quoted from above:

This issue is currently reaching conclusion under Mediation Wikipedia:Mediation_Cabal/Cases/2008-03-27_Corvette_leaf_spring and the moderator has concluded thus far that when discussing the 'Performance and Handling consideration" on the modern Corvette, this cited quote must be added: "Ride and Handling: according to an opinion in Motor Trend magazine, the Corvette C6's transverse leafs "make the rearend behave a bit like a rigid axle. Aftermarket tuners have scrapped them in C5s and C6s for coil-springs". - Above quotes are the mediator HAERMO's actual context verbatim. This represents the Mediators proposed solution to our mediation.

The actual quote from the mediation discussion is as follows:

===Proposal===

How about if you include the cited MT opinion, but also include information about similar issues with the Volvo, to balance the description. For instance, something like:

Ride and Handling: according to an opinion in Motor Trend magazine, the Corvette C6's transverse leafs "make the rearend behave a bit like a rigid axle. Aftermarket tuners have scrapped them in C5s and C6s for coil-springs". However, similar arrangements used by Volvo "to reduce size and weight of the rear suspension [without sacrificing] ride comfort."(cite)

The quoted text was offered by the mediator as a suggested solution. No decision has been reached.Springee (talk) 02:16, 9 April 2008 (UTC)

Additional concerns regarding quotations

Autostream wishes to include the following quote from the article:

make the rearend behave a bit like a rigid axle. Aftermarket tuners have scrapped them in C5s and C6s for coil-springs

While that is in fact verbatim, it was taken somewhat out of context. The full quote is below.

While the C6's carbon-fiber transverse leaf springs are light and packaged well, under some conditions they make the rearend behave a bit like a rigid axle. Aftermarket tuners have scrapped them in C5s and C6s for coil-spring conversions, so it'd be easy to do in a production C7. The C6 has aluminum control arms front and rear, but reductions in unsprung weight would help further.

Note that MT’s actual text states that the problem only exists “under some conditions”. They certainly don’t say the car handles badly as Autostream wants the quote to imply. It is also hardly a definitive statement by MT. Additionally they note that reducing unsprung weight would be good (presumably to address the behavior issue they noted) and is consistent concerns that the leaf spring has not been shown to be the problem.

Additionally, while handling is actually not as subjective as some believe, even the subjective descriptions require some further definition. The paragraph doesn’t actually state what handling problem they are seeing. The phrase “like a rigid axle” ‘’could’’ actually be taken to imply the suspension has ideal camber curves under roll (as rigid axles do). It also doesn’t say under what conditions they perceive this problem. Are we talking about conditions of the road, of the suspension package on the car (which shocks, springs tires etc), of the weather? Do they mean all Corvettes or just those with certain suspension packages? It is a very vague statement and as such we should be careful about imparting specific meaning to it. --Springee (talk) 23:32, 9 April 2008 (UTC)

This article's title is completely ridiculous. Some of it should be on the Corvette page, some of it should be on the leaf springs page. Having articles for individual components on a car doesn't make sense. 192.198.151.129 (talk) 12:55, 23 October 2008 (UTC)

I just finished reading the whole thing and it's quite clear that someone who loves leafsprings and Corvettes wrote a lot of this. How can perception be a disadvantage of a mechanical component? Does it remove from the performance of the part? A bad perception of leaf springs is a disadvantage to a fanboy writing about leaf springs. Faux pas. 192.198.151.129 (talk) 13:09, 23 October 2008 (UTC)

Motor Trend explains what they meant

Autostream had posted a request on the MT Forums for additional explanation regarding the magazine's claim that the leaf spring makes the rear suspension behave "a bit like a rigid axle".

Here is the response he received from tech writer Frank Markus:

They are composite springs, and yes they may be fiberglass reinforced instead of carbon-fiber reinforced. Some people use Composite and Carbon Fiber a bit too interchangeably and I should probably have changed that. Lots of other people just call them plastic which is certainly generic enough to avoid mile-long Wiki argument strings.

As for the handling reference, the point is that when an impact drives one end of the transverse leaf spring up, the other end is at least to some extent driven down, and vice versa. It is this side-to-side linking of forces that is in some ways akin to a live or solid axle, whereas in independent suspensions without a transverse leaf spring there is less force transmitted from an impact on one side of the suspension on the other. Motor Trend Thread

The first point by the author admits the spring material was wrong.

We now know what the author was thinking when using the rigid axle reference. The description is not consistent with the suspension used on the C5 and C6. The description talks about a seesaw effect. For this effect to occur the spring must be centrally mounted. This effect likely did occur in the C2-C4 rear ends (not the C4 front) to some degree due to flexing of the mounts and shifting of the dif housing with respect to the chassis.

This description is not correct with respect to the later cars nor the C4 front suspension which used the leaf spring as an anti-roll bar. What the MT author describes would be the opposite of the anti-roll affect mentioned by Michael Lamm as well as in a number of patents I've found by searching transverse leaf spring in the google patent database.

Additionally, this finite element model of a transverse leaf spring with two widely spaced mounts shows that when one side of the spring is pulled up the other also goes up, not down.

It is now completely clear what the MT article meant. It is also clear that the information was entirely mistake and thus not suitable for the article. Future references should be removed. Springee (talk) 14:04, 30 April 2008 (UTC)

Frank Marcus did NOT write the Motor Trend article of interest.--24.46.144.102 (talk) 23:25, 30 April 2008 (UTC)

My bad Autostream, perhaps he wasn't the writer. However, the MT admin gave his response. I would assume you agree that his response would represent that of MT. It certainly would seem he was at least the person who contributed the particular morsel of information in the article to which you have clung. Any comments on the technical validity of what I have shown above? Springee (talk) 00:33, 1 May 2008 (UTC)

Some content removed

I removed the following content:

"Conventional Leaf Spring vs Corvette Suspension

Conventional leaf spring suspension performance is criticized with respect to independent suspension types for several reasons:

   1. Friction between the individual leaves of the leaf spring impedes smooth articulation of the suspension.
   2. Leaf springs can flex under lateral loads resulting in lateral shift of the axle with respect to the chassis.
   3. High unsprung mass of the rigid axle reduces ride quality and suspension effectiveness.
   4. Deflection of one wheel directly affects the angle of the opposite wheel which can negatively affect cornering quality uneven surfaces.

The above issues do not apply to the Corvette suspension for the reasons listed below:

   1. The monoleaf spring is not comprised of individual elements sliding across each other and thus does not suffer from internal friction.
   2. The suspension uses rigid A-arms to support lateral loads. The leaf spring does not support lateral loads nor does it act as a suspension link. In this way it acts exactly like a coil spring and unlike a conventional leaf spring suspension system.
   3. The Corvette suspension has the same sprung and unsprung components as other independent suspension systems. It does not use an unsprung live axle thus does not have the extra weight of the live axle.
   4. The wheels of the Corvette are free to move relative to each other. As with all independent suspension systems, the movement of one wheel does not force a movement of another."

Point 1 of the first set was actually an issue with the circa-1960s Corvette leaf suspension, which did in fact have multiple leafs. Points 2, 3, and 4 are more aptly characterized as criticisms of a solid rear axle.

Point 1 of the second set is repeated elsewhere, as is point 2 and point 4. Point 3 is again about axles. Like most of these points, there isn't adequate differentiation between the facets of suspension design that are covered in greater depth elsewhere in this article. Alexdi (talk) 22:51, 15 August 2008 (UTC)

Hotchkiss Suspension is the correct, though rarely used term that describes the traditional leaf spring suspension. [6] [7] —Preceding unsigned comment added by 129.59.79.27 (talk) 18:54, 5 September 2008 (UTC)