Why does a rig roll?

[zukkev]

I haven't done the math, but I bet with everything taken into acct, I wouldn't be surprised if my COG dropped by nearly 3" with the changes I made...

 

[TreeClimber]

A rig rolls when the Center of Gravity is no longer within the vehicles width or length, as it relates to the contact points with the earth.

That of course changes with you add inertia into the mix. You can sidehill a sanddune with inertia that if you parked sidehill on it, you'd roll.

Plus, suspension characteristics can drastically shift the location of the center of gravity due to unloading/loading of the springs/shocks. That changing of the CG can not only roll you, but it can also give the vehicle an internal inertia that might carry you over.

Then there are the times when someone basically just drives until you have driven onto one's side. The trail simply turns you over.

 

[boardbysled]

I haven't done the math, but I bet with everything taken into acct, I wouldn't be surprised if my COG dropped by nearly 3" with the changes I made...

You'll have to compensate for weight gained too (not talking about your rig):fawkdancesmiley:

Damn It! I posed that, then realized that my COG is probably REALLY bad if my rigs leaning to the driver side:haha:

 

[zukkev]

You'll have to compensate for weight gained too (not talking about your rig):fawkdancesmiley:

Damn It! I posed that, then realized that my COG is probably REALLY bad if my rigs leaning to the driver side:haha:

So long as you sidehill with the downhill side to your pass side, your GTG!!!:;:fawkdancesmiley:

 

[zukkev]

If the CG is fixed, it's fixed. If the suspension is moving around so is the CG...........
Not only did I not fix the trans but now the steering is jacked too.
that's OK I can outwheel you with the superduty.

:haha::haha::haha:
Wait, what happened to your steering???:yikes:

 

[Boonie Buster]

I did say there are many variables but I was using the physical properties of the rigs size itself as that seems to be the typical argument going...."a wider rig is more stable and safer"

a wider rig, is usually also heavier and higher....speaking full-bodied rigs, no the buggies.

 

[Binder]

:haha::haha::haha:
Wait, what happened to your steering???:yikes:

I think the orbital valve is broken.......but the CG is still the same.:;

 

[Binder]

a wider rig, is usually also heavier and higher....speaking full-bodied rigs, no the buggies.

Weight doesn't matter and the overall height doesn't matter but the height of the CG does when leaning.

 

[Boonie Buster]

Weight doesn't matter and the overall height doesn't matter but the height of the CG does when leaning.

ya, that's what i was getting at, generally a fullsize will have it's COG higher.

 

[bigiron]

On a leaf sprung rig...yes,wider is better depending on how their Anti-wrap bar is built.

What is this Anti-wrap bar you speak of Jeff? and what is its purpose? LMAO....I though it was all related to how big your steelies were?

 

[03 CON]

If the CG is fixed, it's fixed. If the suspension is moving around so is the CG...........
Not only did I not fix the trans but now the steering is jacked too.
that's OK I can outwheel you with the superduty.

Wait!!!! Now I wanna see what is typed in white take place:corn:

 

[Fordzuki]

Driver error.

 

[mark]

In the basic truth, Binder is correct. If no other actions are put toward it, one the COG surpasses the lower most edge of the rig, it will go over.

Gassing it, braking, turning the wheel has to do with either (a) moving the COG within reference to the edge or (b) changing the momentum temporarily to over-come a brief occurrence of the COG outside the edge.

All things static, once the COG goes over the edge, over she goes.

 

[cisco]

The relative gain in stabilility by increasing the track width is dependent on the ratio of the height of the CG to the track width.

Heres a link with more than you ever wanted to know
http://www.jeepaholics.com/tech/cog/

 

[Damnyankee]

Well, it tis past 7...:haha:

Why does a rig roll?
Usually, because the driver is drunk, high, slightly mentally handicap'd, with 1 bad eye and the other has 20/60 vision, driving a 10 ft tall 70" wide, 85" wheelbase Jeep-like (seems to be the politically correct term) on 31" AT tires. Also, the cage is made out of old handicap shitter rail tubing with welds from a 1942 arc welder, and has a b pilar hoop. The seat belts are pieces of rope. But, its got a SBC 350 pushing 600 hp!:cheer:

thats petty much what happened to me.. good thing it was in canada...:haha:

 

[boxboy]

Yes so maybe we should argue height and weight restrictions?:corn:

but if you limit width and length then you are limiting height as you then create a very unstable rig when trying to lift the rig to get bigger tires and yet still trying to stay under the width length limits...

 

[Broken Again]

.
Heres a link with more than you ever wanted to know
http://www.jeepaholics.com/tech/cog/

Wow that brings back some memories....

Made me think of Pokeys(different Pokey...this guy is my friend Bud Boren) Attitude Adjustments.
http://www.jeepaholics.com/attitude/attitude.htm

 

[NotSoPC]

The COG is a very big part in it. All the rest will change from trail to trail or roll to roll. In a normal home built trail rig the COG will not change other then the weight of passengers and gear. The rest will change depending on what you are doing.

If you have a rig (Sammy) with stock axles then step up to yotas with the same backspace then the rig will be more stable. The COG will be lower do to the weight of the new axles, and the contact patch being moved outword will let it lean more before rolling.:awesomework:

 

[Money Mark]

Well, come on CrazyDaze Corey......you seem to have plastered your opinion all over the board in the past on this subject. Lets here your counter argument. This thread is obviously related to your opinion and being out spoken about it.



"Wider is more stable" is correct thinking.......with a piece of wood. Not with a vehicle.

 

[Money Mark]

On a leaf sprung rig...yes,wider is better depending on how their Anti-wrap bar is built.

And that's the Y factor........"Y wouldcha needs onea dem.":redneck: