"HammerheadFistpunch" (hammerheadfistpunch)
08/07/2014 at 15:39 • Filed to: Rant
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"HammerheadFistpunch" (hammerheadfistpunch)
08/07/2014 at 15:39 • Filed to: Rant | 3
| 27 |
I'm a marketer with a love of engineering and damn it all I am getting so tired of trying to explain to people why its OKAY for a frame to flex. Man alive Ford is good with their marketing.
Twingo Tamer - About to descend into project car hell.
> HammerheadFistpunch
08/07/2014 at 15:42 |
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They dont seem to realise that if the frame didnt flex all that energy would still have to be dissipated somehow. Meaning more suspension wear and such, unless the trucks other parts are designed for a solid frame. Flex =/= instant frame breakage, although it will increase rate of fatigue in some cases.
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HammerheadFistpunch
> Twingo Tamer - About to descend into project car hell.
08/07/2014 at 15:45 |
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I'm confident that the rate at which this Tundra's frame fatigues would be increased driving on this course at that speed for its life...but cmon, seriously. Marketing a pickup truck is the art of getting people to come to their own conclusion that the demonstration that is designed to favor your truck clearly shows an engineering advantage in all situations. Its like saying that bigger tires are always better, because the bigger tire on your truck can cross the 18 inch gap and the competitors can't. All good trucks have tires this big. Guh.
dogisbadob
> HammerheadFistpunch
08/07/2014 at 15:46 |
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Oh, I thought the Ford Flex was an SUV thing :p
mazda616
> HammerheadFistpunch
08/07/2014 at 15:47 |
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That video made the rounds of the Internet as "The Truck That Twerks."
I've also seen a video of a product that reduces that vibrating phenomenon, but I can't recall where I found it. All it was was a metal bar of sorts that is placed in the bed.
Mercedes Streeter
> HammerheadFistpunch
08/07/2014 at 15:47 |
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LaTundra twerks better than Miley!
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HammerheadFistpunch
> mazda616
08/07/2014 at 15:48 |
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yes...it did.
SaabLife, because Gripen
> HammerheadFistpunch
08/07/2014 at 15:49 |
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These are my thoughts on the matter.
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dogisbadob
> HammerheadFistpunch
08/07/2014 at 15:50 |
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mazda616
> HammerheadFistpunch
08/07/2014 at 15:50 |
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Found the product's video and the link to Toyota's TSB about the issue.
http://www.tundraheadquarters.com/blog/toyota-fi…
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Twingo Tamer - About to descend into project car hell.
> HammerheadFistpunch
08/07/2014 at 15:56 |
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Indeed, marketing bullshit is bullshit. It's like MPG figures here in the UK. They're lab tested in specific conditions therefore the figures are utterly useless. A guy I know has a focus ecosomething or other with a tiny diesel in it. Quoted something silly like 70mpg, he gets high 30s because the test that determines figures is at such low rpm that in real life when you need to speed up at a good pace the engine is overstressed.
deekster_caddy
> HammerheadFistpunch
08/07/2014 at 15:56 |
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I agree. The issue shown here is that the wheels are leaving the ground. Flex is good. Suspension design is good. Control of the vehicle is most important.
The marketing genius is that they found the harmonic at which this truck was at it's worst, and exploited it. At least the tailgate doesn't open!
Racescort666
> HammerheadFistpunch
08/07/2014 at 16:01 |
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I have seen the whole video (or at least more of it than this GIF suggests). For starters, yes, it was a bit biased, this test was done on Ford's durability test track and yes, the F-150 does much better than the Tundra. However, they also tested a Silverado, which did about as well as the Ford.
While the video might look like a biased demonstration on the surface (it kind of is), this is the durability test that Ford uses to validate their trucks and some of their competitors do pretty well at it.
Found the video, just search for Silver Creek Test, that's what they call this test section:
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HammerheadFistpunch
> Racescort666
08/07/2014 at 16:04 |
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I agree the Silverado did well...or appears to do well. But well at what? This video reminds me of my daughter when she wants to describe height or size of something "I think that's a 15 big" Yes that DOES sound big...15 what dear? There is no reference or evidence to support that failing this test means anything other than failing this test.
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Racescort666
> HammerheadFistpunch
08/07/2014 at 16:24 |
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Part of it is stability which is quantifiable in a 2 minute video but since this test section is part of a durability course, the real answer is how well it stands up to repeated travel over the test track. You won't know until a durability test has been done to see if it falls apart. This is very time consuming as you'd imagine.
You also have perceived durability, the bane of engineering, because it is a real thing and OEMs do design for "perceived durability" which obviously they failed at that.
Long story short: if you're looking for something quantifiable with regard to durability, you can't say anything one way or another from the video or the GIF. From experience, it looks like they'd have problems with fatigue on the Toyota but you can't say for certain without a durability test or at least some sort of data acquisition to make sure the loading doesn't exceed the material capability.
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HammerheadFistpunch
> Racescort666
08/07/2014 at 16:39 |
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I'm not even remotely convinced that flex will be less durable in the long run that stiff.
Flex means less concentrated stress means fewer cracks.
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Racescort666
> HammerheadFistpunch
08/07/2014 at 19:23 |
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I'm trying not to come across as an asshole but I've gotta ask this bluntly: I've got a whole huge comment that explains the relationship between stress and stiffness, it's super math heavy but it's not finished yet. Do you want me to finish it and post it?
Edit: it might actually be better as it's own post.
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HammerheadFistpunch
> Racescort666
08/07/2014 at 19:28 |
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go for a new post, i love science and an always up for leaning new thing, even if it makes me look bad. data is truth, there is always good stuff in the data
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Racescort666
> HammerheadFistpunch
08/07/2014 at 19:31 |
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All right, I'll finish it later tonight.
Philbert/Phartnagle
> HammerheadFistpunch
08/08/2014 at 00:25 |
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I'm a marketer with a love of engineering and damn it all I am getting so tired of trying to explain to people why its OKAY for a frame to flex.
Ok, but doesn't steel (and most other metals except gold) become brittle and break when you "flex" it too much/often?
I would prefer for the frame to stay rigid and let the suspension do the flexing.
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HammerheadFistpunch
> Philbert/Phartnagle
08/08/2014 at 00:45 |
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you know, springs are made of steel.
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Philbert/Phartnagle
> HammerheadFistpunch
08/08/2014 at 00:56 |
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Yes, specially tempered steel, that is purposely designed for repeated flexing.
I have personally seen and even repaired cracked and broken frames that were cracked or broken by repeated flexing.
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HammerheadFistpunch
> Philbert/Phartnagle
08/08/2014 at 00:58 |
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not really, steel generally has good elasticity or Youngs modulus, some more than others but the steel in frames is pretty elastic. tempering increase strength mainly
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Philbert/Phartnagle
> HammerheadFistpunch
08/08/2014 at 01:07 |
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Yes really, springs are specially tempered and prepared for their intended purpose. The steel in truck frames is pretty elastic in comparison to other types, but it will break when it is flexed too often, therefore I would prefer that my truck frame was more rigid and the suspension was more able to do the flexing.
I'm not trying to argue with you, I just don't agree that it is ok for a truck frame to flex like the one above.
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HammerheadFistpunch
> Philbert/Phartnagle
08/08/2014 at 01:19 |
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Sorry i didn't mean to say you were wrong about tempering. I meant to say only that low carbon steel used in trucks is very elastic, its not going to wear out from even lots of heavy flexing. I mean...just take a look at old trucks...so long as rust didn't get it, they are working just fine. Steel is pretty great. Though it is true that heat treating doesnt affect elasticity, only ductility,yield strength and or hardness .
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Philbert/Phartnagle
> HammerheadFistpunch
08/08/2014 at 04:07 |
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Sorry, I should have said alloyed instead of prepared.
Heat treating/tempering does affect elasticity though if the metal has been bent, coiled like a spring or shaped like most truck frames. If it is not heat treated/tempered to relieve the stresses caused by the bending, coiling or shaping then it will lose its resilience, become brittle and eventually break. If you look closely at most truck frames that have had a heavy amount of use you will usually find stress cracks. I have seen them myself most frequently around rivets and in places along the frames they are most prone to flex . I also had an old 69 Ford that was once a farm truck, when restoring it we found a number of cracks in its frame from its years of hard service. The worst area was in the section that bridged the cab and bed because that is where it flexed the most and most often. It does happen quite frequently from what I have seen, but usually not bad enough to be noticed or needing immediate repair.
Here's what I found on a website about spring making in particular, but it applies to most any steel that has been bent or shaped.
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HammerheadFistpunch
> Philbert/Phartnagle
08/08/2014 at 14:06 |
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Tempering restores ductility back to the metal, but it does not change the metals young modulus (elasticity). Brittleness/ductility is not related to elasticity.
Frames can crack no doubt, but a very stiff frame will crack more often than an elastic frame with heavy and frequent use.
Frame metal is also tempered like springs are.
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Philbert/Phartnagle
> HammerheadFistpunch
08/08/2014 at 15:26 |
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We are going to have to just agree to disagree HFP.
To me the statement from the spring making site that " To relieve this stress and allow the steel to maintain its characteristic resilience " means that it does restore the steel's elasticity and brittleness has to be related to it because if it is brittle, that reduces the elasticity by a huge margin.
I don't agree that a very stiff frame will crack/break before an elastic frame either. This one I disagree with purely from experience. I have seen far more pickup truck frames crack and break than I have ever seen larger truck frames crack or break. Therefore a larger/stiffer frame appears to hold up much better IMO. Look at race cars/trucks of all types, I bet 99.9% of them have stiffer frames that allow their suspension to do the work and absorb the bumps and twists. I cannot think of a single one that uses a flexible frame.
I know frame metal is tempered. The newest Ford trucks claim to have lost 60 lbs. by using alloyed, tempered frames made of thinner metal that is supposed to be stronger and stiffer than its predecessors. If a flexible frame was a good idea I'm sure they would have went that route.
Thank you for being able to have a discussion without getting mad and throwing an online fit. I enjoy discussions like this and I have learned a few things to boot.