how to mount roll cage to chassis?

[buckintone]

What's wrong with bushing tie-in's? It's the proper way to do it if done correctly. Unless you have a trail only rig, you can't directly tie your cage to your frame otherwise you render all your flexible body mounts entirely useless and will transfer all kinds of frame vibration right into the body and interior cabin. The most commonly accepted means of addressing this is to use bushings at the cage mount points. Now I've seen some ass backwards attempts at this (on this forum) where somebody used bushing at the frame side basically introducing a hinge (bad thing).

Here's a thread on Pirate about cage tie-in's, the bushing approach is widely accepted as the most desirable:
http://www.pirate4x4.com/forum/showthread.php?t=840005

Here's a good universal bushing tie-in kit:
http://4xinnovations.com/p-RC1715.html

To each his own, most body mounts these days aren't very flexible, usually Poly urethane or plastic with the body lift, some guys put rubber pads between the upper and lower mount plate, that seems ok, but that bolt through bushing thing would just act like a barrel hinge as the cage crushed down. I personally don't think the body mounts isolate much, even rubber ones are so compressed they offer little to no vibration dampening. the motor and tranny mounts certainly do. Great shocks, seats and a rigid chassis will be the most comfortabe, best riding combo. But again, to each his own. Good luck

 

[73azbronco]

I like bulletproof, but let me get this right: The body is only bolted to the frame using some very thin wafers of steel and rubber. If you roll it, how many bodies have separated from the frame?

None, unless really hi speed?

So if I use the same size washers and bolts to mount a rollcage to just the body, then if I roll it, the roll cage is more prone to separate from the body than the body is to separate from the frame unless I tie the cage to the frame?

I'm not buying it.

Anyone have a study of how many cages have separated from the body?

I applaud those taking the effort to maximize safety.

However, these are roll cages, not crash cages or crumple zones or Baja 500 contenders. These are made to protect you if you roll down a hill at low velocity.

I do like tieing into the middle and rear body mounts, but not in the footwells, you have a Dana 44 up front with frame protecting you, and the tie in from the rear to side footwell is sufficient for sideforces.

 

[xcntrk]

I think it comes down to any roll bar or full cage is better then nothing. Any frame tie-in system is better than no tie-in. So at this point is just a matter of debating which of the different approaches are better while all still provide great protection (over nothing).

Personally I think a frame tie-in is important for the rigidity of the cage moreover the push-through or break-away protection (which are nice side affects). Meaning if you have the legs of your B-pillar hoop tied into the frame (by whatever system) you've just secured that mounting point to keep the leg from kicking out in an accident. If the leg kicks the cage structure around it can collapse.

 

[asinor]

I like bulletproof, but let me get this right: The body is only bolted to the frame using some very thin wafers of steel and rubber. If you roll it, how many bodies have separated from the frame?

None, unless really hi speed?

So if I use the same size washers and bolts to mount a rollcage to just the body, then if I roll it, the roll cage is more prone to separate from the body than the body is to separate from the frame unless I tie the cage to the frame?

I'm not buying it.

Anyone have a study of how many cages have separated from the body?

I applaud those taking the effort to maximize safety.

However, these are roll cages, not crash cages or crumple zones or Baja 500 contenders. These are made to protect you if you roll down a hill at low velocity.

I do like tieing into the middle and rear body mounts, but not in the footwells, you have a Dana 44 up front with frame protecting you, and the tie in from the rear to side footwell is sufficient for sideforces.

Sadly, you were just proved correct by a member here. The body separated from the frame...

Very Sad
http://classicbroncos.com/forums/showthread.php?t=203193
Click the links in the article for more information.

 

[73azbronco]

That is tragic and unfortunate. Yet, having a roll cage or not, would most likely have not prevented said tragedy. Bronco's have no crush zone safety/zone required by todays standards.

A roll cage exists to protect rollovers, thats it, hence the name "roll cage", Look here:

http://www.bcbroncos.com/InterriorRollCage.html

That BCB rollcage had no frame tie in (other than rear four body mounts), yet that truck went down the hill numerous times and the cage stayed put.

Now, if your designing a crash cage for racing, thats a different story. But those look like this:

http://dezertrangers.com/vb/fab-shop/63227.htm

My biggest concern driving a Bronco is getting T boned, there is no support protecting you from off angle side impacts. Even full rollcages do not provide adequate protection, only full crash cages would. I submit those under frame tie ins would provide as much support and protection from side impact by themselves without tie into a rollcage.

Like I said, I like bulletproof, but lets not kid ourselves, no one has done a study beyond BCB on how a rollcage reacts during a crash.

 

[asinor]

It is sad and unfortunate. My point was that the body seperated from the frame, like you pointed out in your previous post. The weak point was the body mounts.

 

[Ethansdad73]

I look at my roll over 3x at 55mph and really believe that if i had no just put in new body mounts things would have been worse... I am going to be puting 2x6 steel as rock skis to help with side inpact.. not much but more than whats there now and then cage to frame as well.

Sent from my PC36100 using Tapatalk

 

[2monkeyboys]

Roll cage

on 11/06/2010 i rolled my bronco i was doing about 50mph when i was cut off hit the center divider and flipped over twice i would not be here if i didn't have a cage in it my cage was not tied into the frame but when i rebuilt it i did tied it to the frame take it from some who walk away without any serious injuries. tie it to the frame

 

[sgtandy]

This thread has me concerned. I'm not sure at the moment if the joy of owning and driving an early Bronco outweigh the risks when compared to the safety features found in modern vehicles...

 

[Jeff76]

Everything in life has risks, and you alone can account for the worthiness of the risk in the context of your life.

That being said, I am certain that a life without risk is no life, and in regards to other activities with risks, driving a mechanically solid bronco with good brakes and a full roll cage (tied into the frame or just bolted into a non rusted tub) is on the safer end of the spectrum of life's risks.

Don't let the minutia of this technical discussion of the relative costs and benefits of different cage options make you lose perspective.

 

[73azbronco]

This thread has me concerned. I'm not sure at the moment if the joy of owning and driving an early Bronco outweigh the risks when compared to the safety features found in modern vehicles...

Ditto what Jeff said, drive it.

 

[73azbronco]

on 11/06/2010 i rolled my bronco i was doing about 50mph when i was cut off hit the center divider and flipped over twice i would not be here if i didn't have a cage in it my cage was not tied into the frame but when i rebuilt it i did tied it to the frame take it from some who walk away without any serious injuries. tie it to the frame

Nice job! So, in the crash, this cage was not tied to frame?

Drift of topic, your side nerf bars, are those tied just to frame?