cage design

[GsxrMike]

So i've been searching and reading the last couple of hours about cage design and material. I don't feel I am any more enlightened on the subject. I want to tie my shock mounts into my cage but the only problem is...I don't have a cage.

What type of material should I use? This is going to be mostly offroad, some to and from trails but I don't have any mountains around hear and I don't think I will ever be in the position to flip all the way over 360. I heard DOM or 4130 but what about normall round tubing? HREW or somthing?

How do I design my cage? Should I cut into the floor and bolt to the frame? I am thinking for starters to run a hoop over each seat and tie that together. Run a couple straight pieces at an angle off of the rear hoop (over rear seat) down to the frame. But what about inside the cab?

I am putting this on an 84 K5 blazer.

Anyways please help with any GOOD links or pics or articles anyone has come across. Thanks!

 

[Hogback Fabrication]

Use 1.75" .120" wall HREW or DOM.

HREW (Hot Rolled, Electrically Welded) tubing isn't quite as strong as DOM and its dimensions aren't as precise. Its an acceptable tubing to use in a cage IMO.


DOM (Drawn Over Mandrel) tubing is cold rolled, stronger than HREW and more dimensionally precise. Its quite a bit more expensive but its a great steel to make a cage from.


4130 is chromoly tubing and is the strongest of the 3 but requires special welding techniques and equipment and is $$.


I wouldn't use pipe in a cage.



As to whether to attach it to the frame or body, that depends. If you're going to add tons of tube to the truck (including running through the firewall up to the core support) then go to the frame. If you're going to tie any tubing to the frame you need to stiffen up the whole thing or you risk cracking the frame.

Otherwise, weld the cage to plates that bolt to the floor.

 

[1-tonmudder]

I used 1.75 .120 wall HREW on mine.Pics are in my sig.

 

[DR]

Use 1.75" .120" wall HREW or DOM.


As to whether to attach it to the frame or body, that depends. If you're going to add tons of tube to the truck (including running through the firewall up to the core support) then go to the frame. If you're going to tie any tubing to the frame you need to stiffen up the whole thing or you risk cracking the frame.

Otherwise, weld the cage to plates that bolt to the floor.

Stiffen up the cage or the frame?

 

[Hogback Fabrication]

Stiffen up the cage or the frame?

Stiffen up the frame via more tubing or boxing the frame.

 

[rdn2blazer]

This subject has been discused many many times here. EVERYONE has an openion, and you know what that means . I will say, as I have said before safety is FIRST in my book. Therefore I built my cage to atleast SOME kind of standard as a basline to start. Sure you can use the top cage material like Cromoly and build a crappy cage design and it will crush in the lightest of flops. BUT, I KNOW my design is stout, anyone who has seen my cage will agree. I went with SCORE Rules as a baseline for safety. There rules state a race truck 4000lbs and over MUST use 2" X .120 wall 1018 to 1026 grade DOM tube. So my cage os all 2" X .120 wall 1020 DOM Tube. I also made it a point to buy DOMESTIC tube only.

Sure a cage out of HREW is WAY WAY better then nothing at all, and it will hold up very well, AGAIN, IF designed right. But for me the extra cost of the DOM tube was not a big deal. It DOES cost for sure, but it IS a good amount stronger then HREW for sure. I have manually bent 2" X .120 HREW and 2" X .120 DOM and let me tell you there is a hell of a difference in how tough it bends. Most everyone will hauler "NO NO go 1 3/4 tube, 2" dents easier" I can GUARANTEE 2" DOM will NOT dent easier then 1 3/4 HREW.

Sure, the bigger the tube the easier it will dent. But if that philosophy is is the argument then why not run 1" tube, It wont dent as easy as 1 3/4 tube, right? Ofcourse no one in there right mind would run 1" tube. Look at the difference between 1 3/4 and 2", it's ever so small at most. I just feel having a minimum standard to build a cage by is important as far as safety sake, and as far as my family is concerned. Why not build the safest cage possible you can afford. Why not use the best material you can afford.

If all you can afford is HREW then that I understand, again, it's absolutely better then nothing. But to go with lesser just to save a few bucks and sacrifice safety for your friends or family, I just do not and will never get they way of thinking period. IF you CAN afford DOM go with DOM. God forbid you ever had a nasty multi-roll, roll over, you will be glad you spent that extra bit for the stronger tube.


Bring on the flame, I dare ya!!

 

[GsxrMike]

Now I got another couple questions. First of all thanks for the responces. If I just run it to the floor could I still tie my shock mounts to it? I don't see why not but thought I would ask. 1tonmudder, thanks for the pictures, did you bend and weld all of that yourself? Very nice job! I think I am going to go ponder for awhile. I don't need the cage so much right now as I need the shock mounts and you guys have inspired an idea.

 

[Hogback Fabrication]

Bring on the flame, I dare ya!!

No flame by any means, your stance is a respectable one

And I'm pretty sure it was me that argued with you on this before.

I have manually bent 2" X .120 HREW and 2" X .120 DOM and let me tell you there is a hell of a difference in how tough it bends.

For reference, 1020 DOM has a yield strength of ~70,000 psi

1010 to 1018 HREW is ~45,000-60,000 psi


HREW certainly isn't as strong as DOM but its not pipe either.

Most everyone will hauler "NO NO go 1 3/4 tube, 2" dents easier" I can GUARANTEE 2" DOM will NOT dent easier then 1 3/4 HREW.

Depends on the use.

I would dent the crap out of 2" tube because I drag my tubing over rocks all the time. The dented tube loses most of its structure once its dented, I'd have to replace tube all the time.

As a cage for a fullsize rig, 2" .120" wall works great but I feel its overkill. 1.75" .120" wall has proven itself in fullsize rigs and I feel its more than adequate.

Sure, the bigger the tube the easier it will dent. But if that philosophy is is the argument then why not run 1" tube, It wont dent as easy as 1 3/4 tube, right? Ofcourse no one in there right mind would run 1" tube.

Well, its all a trade off. My rocker tube, B pillar and door tubing are 1.625" .135" DOM. They have resisted any denting so far and its not like they've been untouched You have to design the tubing around the weight of the rig.

But in a fullsize, where you really can't expect to roll it more than once or twice before you need a new truck, denting isn't going to matter. Bigger tube will be stronger in a single impact.

 

[Hogback Fabrication]

If I just run it to the floor could I still tie my shock mounts to it? I don't see why not but thought I would ask.

Sure, but you'd still have to run tubing through the firewall somehow and then attach it to the body which might be difficult. If you have access to a bender, just make some shocks hoops.

 

[GsxrMike]

Yeah I was thinking rear shock mounts when I typed that. But I need them in the front as well. The idea I had for the rear was get a large plate that would fit from wheel well to wheel well and bolt it to the body. Bend some shock hoops and attach to the plate. What do you think? I don't want to just run hoops on the front because I am afraid I will crack my frame as so many people running the super duty towers have. I was thinking hoops in the front with a crossmember over the engine that will bolt to the hoops so I can remove it. What do you think? Any other ideas?

As far a HREW or DOM I think HREW would suit me just fine. I have never rolled or even tipped a rig and none of my friends have ever rolled or tipped a rig (just the way we wheel)

 

[1-tonmudder]

1tonmudder, thanks for the pictures, did you bend and weld all of that yourself? Very nice job!

Heck no,I suck at bendin tube.Their's a old school circle track guy here local that did it.It's just a plain ol no frills cage.

But for me the extra cost of the DOM tube was not a big deal. It DOES cost for sure,

The last time we priced DOM it was gonna almost double the price of a cage and that was about 2 months ago.

 

[Greg72]

As far a HREW or DOM I think HREW would suit me just fine. I have never rolled or even tipped a rig and none of my friends have ever rolled or tipped a rig (just the way we wheel)

Mike,

Now that you've made this type of comment twice in the thread, I'm going to call you on it.... Of COURSE, nobody THINKS they are gonig to have a bad rollover. Everyone wants to think that the worst that will happen is a gentle flop where even a basic cage will suffice.

Take a look at some YouTube 4X4 videos of rollovers and/or flops. I've seen a few that started out looking pretty mild, then suddenly the energy of the initial flop induced a much more severe 2nd event where the vehicle rolled multiple times. Once a vehicle has started to roll or flop, you don't get to choose how severe the event is going to be...it's all decided by gravity and the dynamics of that moment.

My point is only this: You don't have to build a jungle-gym cage with 8-million gussets and braces, but if you're going to build a cage AT-ALL you should at least borrow heavily from proven designs and build something that is capable of dealing with a significant rollover. It doesn't take much more money and time to build a cage that is safe and strong, than one that is merely "decorative".

 

[DR]

Mike,


My point is only this: You don't have to build a jungle-gym cage with 8-million gussets and braces, but if you're going to build a cage AT-ALL you should at least borrow heavily from proven designs and build something that is capable of dealing with a significant rollover. It doesn't take much more money and time to build a cage that is safe and strong, than one that is merely "decorative".

I agree. I'm no cage expert for sure, but I do know car wrecks. And it sure seems to me that a cage that is not built well enough could end up making things worse. Such as weak tubing coming in on you, or bending just far enough for you to smash your head on it.. Seems to me like a cage would be one of those things that you cant really over do. You cant really be "too safe" right?

 

[Hogback Fabrication]

I agree. I'm no cage expert for sure, but I do know car wrecks. And it sure seems to me that a cage that is not built well enough could end up making things worse. Such as weak tubing coming in on you, or bending just far enough for you to smash your head on it.. Seems to me like a cage would be one of those things that you cant really over do. You cant really be "too safe" right?

Yeah, but there's a line. Why not use 3" tubing? or 4"?

 

[70jimmy]

As far a HREW or DOM I think HREW would suit me just fine. I have never rolled or even tipped a rig and none of my friends have ever rolled or tipped a rig (just the way we wheel)[/quote]


These people were just out for a scenic drive on a pretty easy 4 wheel drive road. They were also traveling only a few miles per hour when this happened.

I see what is in the first pic so when cage time came I got what is in the 2nd pic. If a roll happens I want to know I did what I could to protect my passengers.

2 inch .120 wall DOM.

 

[GsxrMike]

As far a HREW or DOM I think HREW would suit me just fine. I have never rolled or even tipped a rig and none of my friends have ever rolled or tipped a rig (just the way we wheel)

These people were just out for a scenic drive on a pretty easy 4 wheel drive road. They were also traveling only a few miles per hour when this happened.

I see what is in the first pic so when cage time came I got what is in the 2nd pic. If a roll happens I want to know I did what I could to protect my passengers.

2 inch .120 wall DOM.[/quote]

I agree with all of you that a mild tip can turn deadly and that I should build a cage correctly. What I am saying is that where I wheel it is all slow and flat and muddy! The picture above with the destroyed vechicle that was traveling slow was obviously on a serious hill (or mountain). At slow speeds on a mildly flat surface I don't see anyway possible to get into a bad rollover accident. I live in Kansas and wheel in vallys through creeks and mud pits. I think a cage is a good idea and I would like to tie my shock mounts into it. So I have not decided yet on what to do. I was just trying to get an idea of how I should design a cage for the type of wheeling I do.

 

[lak2004]

As far a HREW or DOM I think HREW would suit me just fine. I have never rolled or even tipped a rig and none of my friends have ever rolled or tipped a rig (just the way we wheel)

These people were just out for a scenic drive on a pretty easy 4 wheel drive road. They were also traveling only a few miles per hour when this happened.

I see what is in the first pic so when cage time came I got what is in the 2nd pic. If a roll happens I want to know I did what I could to protect my passengers.

2 inch .120 wall DOM.[/quote]

Is that picture from Black Bear?

 

[twoslo4five0]

But in a fullsize, where you really can't expect to roll it more than once or twice before you need a new truck, denting isn't going to matter. Bigger tube will be stronger in a single impact.

this is exactly what i thought when i had my cage built....how many times can you roll a truck and expect it to live??how many times would you TRUST IT after a roll over...if im involed in a roll over (not a flop) im not sure that i wouldnt be thinking of starting all over if it was hrew or dom...my cage is 1 3/4 hrew .120 and was about half the price of dom...

 

[1-tonmudder]

nice clothes line

 

[twoslo4five0]

nice clothes line

what its being used for right now