Talk:MacPherson strut

Needs an English Translation :-)

"... compression link stabilized by a secondary link which provides a bottom mounting point for the hub or axle of the wheel. This lower arm system provides both lateral and longitudinal location of the wheel. "

Provides location? secondary link .. provides a bottom mounting point ...

I expect this is crystal clear if you already know it. The diagram is v. clear, but a few labels would make it much more intelligable.

Having said, that, I did manage to work out what it is the garage was talking about. Thanks —Preceding unsigned comment added by 86.29.207.80 (talk) 15:33, 30 September 2007 (UTC)

I'm still mystified. Part of the problem is that as one of the many colorblind wikipedia readers, I can't distinguish blue from purple or yellow from gren and have no idea what some of the parts of the picture are referring to. And it is still not clear what the "strut" is - how it different from a shock absorber? What were previous non-MacPherson struts like? etc. Help.... --70.91.87.57 (talk) 03:54, 6 March 2008 (UTC)

That good old Anti-Roll Bar

In a history of cars that I read, a distinction was made between the MacPherson system proper and the mere struts that in fact preceded it in race cars. This was the anti-roll bar, which saved money by also serving as the trailing link. This can be imagined as a relatively thin rod that goes forward from the lower pivot, turns 90 degrees inward and immediately goes through a hole in the frame, across the car to the other side and through a hole in the other side of the frame and turns rearward to the pivot on the other wheel. When both wheels rise or fall, this does not affect their movement. But when one wheel rises or falls, the bar resists its movement.

I think that the use of the term on this page has changed to merely be any old strut, and not Mr. MacPherson's particular design feature, which I have noted above. The picture placed on this page does not show this detail, nor does the description.

Also, in the book it said that an Italian firm (probably Fiat) had the idea before MacPherson, but did not prosecute. Sobolewski 23:28, 31 October 2006 (UTC)

I'm not sure that the title "..anti-roll bar..." was the most appropriate for this discussion.

However, more seriously, I have seen the following claim (by Setright, although not in one of the sources quoted, and my paraphrase):
Earle S MacPherson patented the use of the anti-roll bar connection as the trailing link location device in a strut suspension while working for one of the US 'big three' auto manufacturers (sometimes stated as Ford, sometimes GM: maybe he moved across town between the patent and the application?). So, the distinctive thing about his patent is not the strut, per se (struts were already known, but not in common use), but the use of the a-r bar for geometrical control. From that point of view, a MacPherson strut ought to be one which utilises this form of control, not just a strut. These days, at least in Europe, the a-r bar is not used in this 'role' (sorry), so these are struts, but not MacPherson struts.

On the other hand, it can be argued that MacPherson was the populiser of strut supension, even though his patented variant of the strut is not the one in popular use today. And so it is his popularisation not the patent that is being commemorated in the use of his name.

In this context, you can see why Fiat might have thought this too messy an area into which to intervene by sending in m' learned friends. Mark w69 10:28, 5 October 2007 (UTC)

Example picture

I think the system shown on the AWD car is really a Chapman strut since it's on the rear, non-steering wheels of that car, but this distinction, for the purposes of this article, is probably just an unnecessary technicality. kevinthenerd (talk) 10:10, 27 May 2008 (UTC)

Sorry Kevin, please hand in your nerd badge. The rack is not visible, but the tie rod is not visibly grounded at the chassis either. Cheers Greg Locock (talk) 11:26, 27 May 2008 (UTC)

Regarding the example image at the top of the article, the legend states that "The front of the vehicle is at bottom left of the image." I cannot speak for the implementation in every model of car that uses MacPherson struts, but in the Subarus I'm familiar with the front of the vehicle would be at the top right. The tie rod connects to the front of the knuckle, and the radius rod reaches back toward the center of the vehicle. — Preceding unsigned comment added by 209.112.145.40 (talk) 06:57, 24 April 2016 (UTC)

2 legends for the same picture

I do not get the difference between the 2 pictures int the Chapman strut and mac pherson. It seems that the same picture has been used with 2 different legends ? —Preceding unsigned comment added by 71.118.52.10 (talk) 02:30, 12 October 2008 (UTC)

Improvement Needed

I think this article fails to set forth what really distinguishes the subject design from other competing designs, past and present, and the article would be better if it did. Non Curat Lex (talk) 06:08, 2 December 2008 (UTC)

And it is rather confusing, since a lot of terms are introduced, some of which seem to designate the same elements; and which are not reflected by the figure that again uses other terms. I must say that I have not understood it. Thyl Engelhardt

Honda CRV - the picture

The "example of a Chapman strut" is used to illustrate a "multi-link type rear independent suspension" in the article Independent suspension. I can't see no chapman strut in the picture. Maybe it is wrong here.

Other examples of macpherson struts that don't feature a spring

All the Citroen models with hydropneumatic suspension have front macpherson struts with no spring as the springing medium is the spheres on top of the strut. —Preceding unsigned comment added by 81.86.155.195 (talk) 02:18, 8 February 2010 (UTC)

88.69.33.208 (talk) 14:12, 1 September 2009 (UTC)

Motorcycle nomenclature anyone?

The same basic design, a shock rod inside a coil spring, is also widely used in motorcycles, in conventional rear suspensions with one of them on either side of the rear wheel as well as sophisticated linkage type suspension with central monoshock. But they wouldn't be called MacPherson in that context, would they? I've seen the word 'coil over' but as a non-English native, it strikes me as slang or vernacular? --Cancun771 (talk) 06:53, 16 June 2014 (UTC)

No that is either a strut or a coilover, certainly not MacP. Coilover is actually a better word, less ambiguous than strut. Greglocock (talk) 08:05, 16 June 2014 (UTC)

No, neither the front nor rear of a bike are MacPhersons. A MacPherson strut (as distinct from other struts) defines something about how track control is handled. This is inapplicable to bikes, therefor they're not MacPhersons.

Nor are bikes strut suspensions at all (we need a clear article on strut suspension but the accurate content we have had keeps getting wiped). The rear uses some form of swinging arm so that isn't a strut. The front isn't a strut because that's two coilovers, one each side, and braced at the headstock by the triple tree. The only strut suspension on bikes is that rarity (Cannondale mountain bikes being the only major user, maybe Mike Burroughs customs too) where there is a single-sided telescopic front fork and an overhung stub axle from it. Andy Dingley (talk) 18:55, 16 June 2014 (UTC)

Ford Vedette suspension?

There's a question as to the suspension of the 1949 Ford Vedette.

There is broad agreement that the Vedette became an early car to use MacPherson struts. At least by 1954 (by which time it was Simca building them, not Ford) it used struts. Also in 1950 the Ford Consul was using struts.

The question is, did the 1949 Ford Vedette use struts from the outset, or did it use a different suspension system (unequal length wishbones have been suggested, presumably with lever shocks? Was the bodyshell then redesigned for struts when it went to Simca?

(Posted at all three of the relevant talk pages, but please reply at Talk:MacPherson strut#Ford Vedette suspension?)

Andy Dingley (talk) 13:06, 8 October 2014 (UTC)

If you want an answer in English, Andy, as in a source, check this out:

http://www.vwtrendsweb.com/features/0306vwt_macpherson_strut_suspension/

I have a French language source - in fact a succession of sources because the same phrase appears in each annual review of what was on display at the Paris motor show - which described the front suspension of the Vedette as it appeared on the show stand in October 1948 as being "à roues indépendants avec ressorts hélicoïdaux". I think that may very well be French for MacPherson struts albeit before MacPherson's name had been applied to them. However, if someone with a better combination of technical French and understanding of suspension geometry were to confirm (or refute) what I think on this ... well, that would be reassuring (or not). But in my own mind I have always understood that the Ford Vedette was the first car with this front suspension, but of course it was uncommonly discourteous of the chaps not to do the thing first off in a country where they speak God's own language.... Regards Charles01 (talk) 21:31, 8 October 2014 (UTC)

I'm inclining more and more to the view here [1] that the Vedette was already under development when MacPherson arrived at Ford in 1947 and had an independent suspension design based on wishbones. This would make the British Ford Consul the first, in 1950. Andy Dingley (talk) 00:09, 9 October 2014 (UTC)

Without actually seeing the components for the front suspension, or at least suitably detailed drawings of them, I'm not sure this can go a lot further. There's an understandable ignorance of what was going on in French among English language writers and, for all I know, vice-versa. And if you stick with wiki sources, you're stuck with that happy state of mutual ignorance. But in terms of knowing how the front suspension was actually configured, there is presumably objective truth to be had from some old collections of cars or car museums somewhere. Though I see that on this page Leonard Setright (who else?) had his own eloquent explanation for why a MacPherson strut really is not quite what I had thought it. I reckon I could go into a plant where they make the things, look at a bin of completed strut sub-assemblies awaiting delivery to an auto-maker who still uses the things, and tell you they are struts. But if it all ties in with how the sub assembly is related to an anti-roll bar, then even I begin to lose confidence that a strut is what I thought it was. Hmmmm Charles01 (talk) 05:44, 9 October 2014 (UTC)

Or at least some detailed contemporary technical drawings? Charles01 (talk) 05:45, 9 October 2014 (UTC)

I've been trying to write strut suspension for a couple of years now and I still haven't even got an intro paragraph for the lead. Just what does define a "strut" in this sense? Is Stout a strut? Fornaca?

Just try to justify MacPherson's 1947 patent as a novel claim over Fornaca's from 20 years earlier – you can do it, it makes sense to do it (Fornaca's "elegant" design sucks and is unworkable in practice, in a manner that's not unusual for Fornaca) but it's far from obvious to the layman. It's even harder to justify the 1949 patent as being non-infringing of the 1947 patent, which is crucial as Ford would never have adopted a design so widely if it involved license fees to GM. One of the bigger faults of the MacPherson strut performance-wise, right into the '80s, just to avoid MacPherson infringing his own patent. Andy Dingley (talk) 10:59, 9 October 2014 (UTC)

If you've studied the wording of the patent submissions as part of your (already)two year projected entry, that's probably as close as you'll get to a definition, even if some "letter of the law trumps spirit of the guideline" wiki-pedant might then start muttering about original research. There must have been some legal musings on paper about why the '49 patent didn't infringe the GM one, but they were most likely secret at the time and buried in an archive box deep in a basement - or simply shredded - since. This talk of Fornaca sent me scurrying to the Italian wiki entry on MacPherson Struts, but there didn't seem to be much there about the Fornaca design. He says something, I think, about Cottin & Desgouttes, but as far as I can make out their front suspension units, though they did indeed incorporate individual shock absorbers one per wheel, used traditional lever-style shocks (that's shock absorbers on the British side of our language) rather than the telescopic ones that go in MacPhersons struts. It might have prodded MacPherson in a good direction, but he certainly didn't copy it.

Well, you made me think about the definition of a MacPherson strut more than I ever did before, and I figured you deserved some kind of an answer, but I'm afraid I don't have any definitional stuff beyond where I think you must already be at. But MAYBE someone else reading this does.

Before the war GM had something called Synchronous springing based on a patent they purchased from the French who thought of it as Dubonnet suspension. Fitted on small European sized cars I gather it made cars a bit uncontrollable, especially on bumpy roads with bends in them, and at least in the early years, though maybe in North America it worked better on heavier cars with longer wheelbases and straighter roads. I don't know how closely that ties in with the strut design favo(u)red by Ford after the war, but it does at least highlight the fact that radical solutions for improving suspension were seen by the big automakers as one of the routes to competitive advantage at that time.

Success Charles01 (talk) 14:59, 9 October 2014 (UTC)

The 1949 patent dodges the 1947 patent by virtue of simplifying the lower control links and also by discrediting the novelty of the 1947 patent by citing precedents. The 1949 track control arm simplifies the 1947 constructed wishbone by also relying on the anti-roll bar (itself a GM patent!) as a radius rod.

Dubonnet suspension is great for heavy cars in a straight line over bad roads (America) but suffers badly from a Dutch roll if the mass of the body starts to move from side to side too. As they didn't (ever?) have anti-roll bars too, this is a problem, especially when cornering. It's a bit like Citroen DS suspension, before they worked out how to control the valving properly, and why they have a separate accumulator on each wheel, rather than a central accumulator. Andy Dingley (talk) 15:17, 9 October 2014 (UTC)

Picture legend

The picture should be reworked to avoid colour as the sole means of conveying information. This presents a problem to colourblind users. LeadSongDog come howl! 13:38, 22 April 2015 (UTC)

Cottin-Desgouttes

Photo here, but I've found little other information as yet. http://www.antiqbrocdelatour.com/Les-collections/voitures-anciennes-doc/2e-dessins-anciens/Cottin%20et%20Desgouttes%20sans%20secousse%20suspention%20speciale%20a%20roues%20independantes%20de%201926.jpg Andy Dingley (talk) 21:00, 17 March 2016 (UTC)

Ha, good stuff, so it uses coil overs, or at least coil springs and a sliding pillar, and a leaf spring as a lower arm. That does not, in my opinion, match the description in the article. On the other hand the shock is articulated at the knuckle, which defeats the main feature of a modern MacP. The rack is presumably a long way back in the car, with tie rods running mostly fore-aft. Even so bump steer would have been horrific. Greglocock (talk) 00:08, 18 March 2016 (UTC)