RPG's new Steering Tie Rods!!!!

[bstoner59]

I always have coffee!!

 

[RPG]

I'll admit I'm confused by your response. On one hand you say that you won't post information because it might inspire someone with lesser knowledge than yourself to make or market their own set. Then in the next breath you say you purposely didn't mention the dangers of hydrogen embrittlement during heat treatment? It's this kind of information that would keep people from buying from critical parts from people who don't know what they're doing! And it would keep anyone with a drill press and a lathe from thinking they could just throw their own kit together.

As far as Herbst and the aluminum rods... I know aluminum tie rods have been used by many racers. I've used them myself. But it's very possible that they use much larger and stronger threads. (I'm not up on trophy trucks but my guess is 1" or 1.25" is used... much stronger than 0.75")

Oh, one thing I'm pretty sure of is that most trophy trucks weigh less than a Raptor.

But you didn't claim your tie rods were made from aluminum like the trophy trucks... you made specific claims when someone asked you about thread strength.

What caught my eye was your claim that a 3/4" thread in aluminum was stronger than the stock 0.472" steel threads... that fine threads are stronger than coarse threads... and the implication that more thread engagement than stock adds substantially to thread strength.

All of those claims are hard for me to believe and you aren't backing them up with any engineering or test data.

As far as thread engagement? If I'm wrong, show me where. As counter-intuitive as it sounds, the first few threads carry about 80% of the load. In softer materials, the loads spread out a little more but there is no significant increase in thread strength once you exceed an engagement 1.5 times the bolt diameter in aluminum.

In reality? Ford's tie rod threads might be 10 times stronger than they need to be. Your threads might only be 7 or 8 times stronger than they need to be. Both might be overkill. But that still doesn't make it right to claim something is stronger than stock when it may not be.

Mark,

I'm not going out on a limb here by saying if there is a room with ten people in it, I might be about 2nd or 3rd from the bottom when it comes to engineering intelligence. And that number might be giving myself to much credit

Something tells me both you and Corey would arrive at the same conclusion about the strength of the rod itself with all the facts laid out on the table. As you know, lab testing like you are mentioning is very expensive and not many vendors on here could afford something like that unless people want to spend $1200 for a steering Tie Rod. We are not a multinational company that can just pay for Lab testing. We have to rely on his years of real world hands on wrenching in SCORE,BITD and MDR races plus the designing of class 10/1/TT, and not to leave out his years of formal education to achieve the best resulting products available for the F-150 platform

You mention that you aren't up on the Trophy Truck crowd and that’s ok. Not many are including myself. I've always just watched in awe in the pits and helped out the best I could when the real guys like Corey and others made things happen. I personally am beyond fortunate to have him as my business partner because he has made a living over the past 10 years designing products for other people. With regards to telling the whole internet of what works and what doesn't work because some shady tree mechanic might try to copy us and have drastic results. Unfortunately we can only worry about what we produce and aren’t in the business of writing online text books to help people reproduce or copy what we or any other manufacture have built. Nor will we publicly question any other vendors marketing claims about strength, design or safety. Whether anyone agrees or doesn’t agree with this stance is irrelevant. It is our position and won’t change for the simple reason there may be an underlying factor in company “X”s design that we aren’t aware of.
All of the manufactures of goods on this forum have to stand on their own two feet, and the consumer has to sift through the BS and make the decision on their own about what they do or do not feel comfortable with bolting on their truck. My own personal truck has 2 cars seats in it and I would never put something on my truck that I don’t believe in. And yes, I take my girls off-roading with me, or as they call it “going bumping”. And others on this board have seen how I drive my truck.

Now, the reason he posted up the picture of Herbst Truck is because it was listed at about 7800lbs and many believed it to be in the ballpark of 8300lbs. we were actually discussing this very thing last Wed with one of the original Ford Rough Riders as he was reflecting on the glory days of the factory backed programs. If I recall correctly the Herbst truck had on average of 100 more tubes designed into it when compared to the next closest competitor’s truck, and the guy who designed the Herbst truck is a legend with basically what was and unlimited checkbook.

If what "I" wrote sounds misleading in anyway then I apologize to everyone on this forum. I don't think you are anyone else will question that the hardware used in the RPG Tie Rods is far superior to the OE application. This leaves the debate about the Rod itself. I personally think Cory explained the strength of the rod the best he can but I will make sure to have him give a detailed pic and write-up comparing RPG rods vs. OE rods.
I hope you have a blast on the Mojave trip and hopefully I get a chance to meet you Barstow. That’s a great trail with perfect terrain for the Raptor, should be a really fun weekend for you guys.


Best Regards,
Jarrett

---------- Post added at 03:39 PM ---------- Previous post was at 03:22 PM ----------

Annnnnnd.... It's on.

Nope, it's never going to go there.

 

[BIRDMAN]

I'll admit I'm confused by your response. On one hand you say that you won't post information because it might inspire someone with lesser knowledge than yourself to make or market their own set. Then in the next breath you say you purposely didn't mention the dangers of hydrogen embrittlement during heat treatment? It's this kind of information that would keep people from buying from critical parts from people who don't know what they're doing! And it would keep anyone with a drill press and a lathe from thinking they could just throw their own kit together.

As far as Herbst and the aluminum rods... I know aluminum tie rods have been used by many racers. I've used them myself. But it's very possible that they use much larger and stronger threads. (I'm not up on trophy trucks but my guess is 1" or 1.25" is used... much stronger than 0.75")

Oh, one thing I'm pretty sure of is that most trophy trucks weigh less than a Raptor.

But you didn't claim your tie rods were made from aluminum like the trophy trucks... you made specific claims when someone asked you about thread strength.

What caught my eye was your claim that a 3/4" thread in aluminum was stronger than the stock 0.472" steel threads... that fine threads are stronger than coarse threads... and the implication that more thread engagement than stock adds substantially to thread strength.

All of those claims are hard for me to believe and you aren't backing them up with any engineering or test data.

As far as thread engagement? If I'm wrong, show me where. As counter-intuitive as it sounds, the first few threads carry about 80% of the load. In softer materials, the loads spread out a little more but there is no significant increase in thread strength once you exceed an engagement 1.5 times the bolt diameter in aluminum.

In reality? Ford's tie rod threads might be 10 times stronger than they need to be. Your threads might only be 7 or 8 times stronger than they need to be. Both might be overkill. But that still doesn't make it right to claim something is stronger than stock when it may not be.

my understanding of fine v coarse threads has always been that when comparing two identical joints(size, material, length, thread engagement, etc) that a finer thread will be stronger in regards to tension and loosening from vibration. longer thread engagement, thicker diameter, finer pitched threads...RPG is making all the right noises. the only unknown for me not being an engineer is alum vs. steel. otherwise it all seems in check Mark

 

[MarkT]

Mark,

SNIP As you know, lab testing like you are mentioning is very expensive and not many vendors on here could afford something like that unless people want to spend $1200 for a steering Tie Rod. We are not a multinational company that can just pay for Lab testing.

I only mentioned the thread testing... which does not necessarily need to be done in a lab... because of the claims made that a 3/4" thread in aluminum is as strong as steel threads. :deadhorse:

SNIP Unfortunately we can only worry about what we produce and aren’t in the business of writing online text books to help people reproduce or copy what we or any other manufacture have built. SNIP

Never asked for an online textbook. Just wanted to see the justification or some proof of the claims made for thread strength.

If I recall correctly the Herbst truck had on average of 100 more tubes designed into it when compared to the next closest competitor’s truck, and the guy who designed the Herbst truck is a legend with basically what was and unlimited checkbook.

And they used what diameter threads on those tie rods? If the RPG rods use the same size threads as the Herbst truck, then it's valid. I had an RC car with aluminum tie rods too but I think you'll agree it's ridiculous to make the comparison to a Raptor.

I don't think you are anyone else will question that the hardware used in the RPG Tie Rods is far superior to the OE application. This leaves the debate about the Rod itself. I personally think Cory explained the strength of the rod the best he can but I will make sure to have him give a detailed pic and write-up comparing RPG rods vs. OE rods.

That would be interesting.

I hope you have a blast on the Mojave trip and hopefully I get a chance to meet you Barstow. That’s a great trail with perfect terrain for the Raptor, should be a really fun weekend for you guys.


Best Regards,
Jarrett

I plan to have a blast! Not planning on debating engineering topics. I think I've said more than enough.

---------- Post added at 06:12 PM ---------- Previous post was at 05:48 PM ----------

my understanding of fine v coarse threads has always been that when comparing two identical joints(size, material, length, thread engagement, etc) that a finer thread will be stronger in regards to tension and loosening from vibration. longer thread engagement, thicker diameter, finer pitched threads...RPG is making all the right noises. the only unknown for me not being an engineer is alum vs. steel. otherwise it all seems in check Mark

I have a little "hands on" experience in testing this kind of thing as well as some engineering background. Anyone interested in the facts about threads can probably find more than they'd ever want to know on the Internet. Here's two links to get started:

General info:

http://www.fastenal.com/content/feds/pdf/Article - Screw Threads Design.pdf


More specific info on thread engagement stresses:

http://www.bastionogp.com/technicalPapers/Bolt Thread Loading.pdf

You'll note that in their example that the sixth thread is carrying less than 2% of the load. The seventh thread would probably carry less than 1%. The eighth, even less. More thread engagement, as counter-intuitive as it sounds, does not mean significantly more thread strength.

From my experience to equal the strength of a 0.472" steel thread, you'd need to be using somewhere around a 1" thread in aluminum.

Again, I'm not saying 3/4" won't work just fine. (I really don't know). I'm just saying I have a hard time believing it's "stronger than OEM."

 

[BIRDMAN]

I only mentioned the thread testing... which does not necessarily need to be done in a lab... because of the claims made that a 3/4" thread in aluminum is as strong as steel threads. :deadhorse:




Never asked for an online textbook. Just wanted to see the justification or some proof of the claims made for thread strength.



And they used what diameter threads on those tie rods? If the RPG rods use the same size threads as the Herbst truck, then it's valid. I had an RC car with aluminum tie rods too but I think you'll agree it's ridiculous to make the comparison to a Raptor.



That would be interesting.



I plan to have a blast! Not planning on debating engineering topics. I think I've said more than enough.

---------- Post added at 06:12 PM ---------- Previous post was at 05:48 PM ----------



I have a little "hands on" experience in testing this kind of thing as well as some engineering background. Anyone interested in the facts about threads can probably find more than they'd ever want to know on the Internet. Here's two links to get started:

General info:

http://www.fastenal.com/content/feds/pdf/Article - Screw Threads Design.pdf


More specific info on thread engagement stresses:

http://www.bastionogp.com/technicalPapers/Bolt Thread Loading.pdf

You'll note that in their example that the sixth thread is carrying less than 2% of the load. The seventh thread would probably carry less than 1%. The eighth, even less. More thread engagement, as counter-intuitive as it sounds, does not mean significantly more thread strength.

From my experience to equal the strength of a 0.472" steel thread, you'd need to be using somewhere around a 1" thread in aluminum.

Again, I'm not saying 3/4" won't work just fine. (I really don't know). I'm just saying I have a hard time believing it's "stronger than OEM."

the first link clearly says fine threads are stronger in tension? i'm not trying to argue, wondering if we're trying to make 2 separate points.

 

[MarkT]

the first link clearly says fine threads are stronger in tension? i'm not trying to argue, wondering if we're trying to make 2 separate points.

Page 4, right?

It says fine thread bolts are stronger in tension. This is because fine threads are not cut as deep so the bolt has a larger minor diameter.

This is not the same as saying the threads are stronger... in fact, on the opposite side of the comparison it says about coarse threads: "Stripping strengths are greater for the same length of engagement"

Fine thread = stronger bolt

Coarse thread = stronger threads

 

[BIRDMAN]

Page 4, right?

It says fine thread bolts are stronger in tension. This is because fine threads are not cut as deep so the bolt has a larger minor diameter.

This is not the same as saying the threads are stronger... in fact, on the opposite side of the comparison it says about coarse threads: "Stripping strengths are greater for the same length of engagement"

Fine thread = stronger bolt

Coarse thread = stronger threads

right, so do you think the tie rod shaft its self would yield before the threads stripped based on its application, making the overall strength of the shaft more important than the type of threads?

However, a bolted joint should be designed to
always force the failure in the bolt shank and not in the thread and therefore, if designed properly, this type of thread stripping should not occur.

The above findings also suggest that a larger number of engaged threads (fine pitch) will
improve the performance of the joint as the stresses are distributed over a larger area; hence
reducing the resulting local stress concentrations.

 

[MarkT]

right, so do you think the tie rod shaft its self would yield before the threads stripped based on its application, making the overall strength of the shaft more important than the type of threads?

I'm really not bashing the part or the design... just some of the claims and statements.

For one, coarse thread rod ends might be made of "unobtainium" so you might have to use fine thread. I understand that. But the fine threads are not more resistant to stripping than the OEM coarse threads and more thread engagement than OEM does not add much strength. Those claims are what I'm questioning.

IMHO, the internal aluminum threads would fail in tension before the steel rod end threads or the tie rod shaft. And this might actually be a good thing. Kind of a "fuse" in the system. If the tie rods are too strong you could easily destroy the rack or spindle. I'd rather have a tie rod tube fail first.

 

[BIRDMAN]

I'm really not bashing the part or the design... just some of the claims and statements.

For one, coarse thread rod ends might be made of "unobtainium" so you might have to use fine thread. I understand that. But the fine threads are not more resistant to stripping than the OEM coarse threads and more thread engagement than OEM does not add much strength. Those claims are what I'm questioning.

IMHO, the internal aluminum threads would fail in tension before the steel rod end threads or the tie rod shaft. And this might actually be a good thing. Kind of a "fuse" in the system. If the tie rods are too strong you could easily destroy the rack or spindle. I'd rather have a tie rod tube fail first.

that's what i am questioning though is if the threads will fail first. if not, all this is for nothing. i'm curious. thanks for the links

 

[RPG]

Ok, so on Wed we are going to perform a test and video tape the whole thing. We will only edit the parts out that have nothing to do with the test. It will put this whole issue to rest.

Thanks for all the feedback and questions. Questioning vendors claims is a good thing and I applaud MarkT for standing his ground and questioning us. It makes us stay on our toes and allows all of you to see if what we say is BS, or actually legitimate. We stand behind what we build and like I have always said since we started this thing, nothing makes it to market before we prove it on our own trucks first.

Stay tuned for the test video. It will be interesting to watch... Think of it as our own little fordraptorforum myth busters.