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Discussion Starter · #1 ·
Hi everyone! I would like to know if there is any documented information about the maximum degree angles both vertical and horizontal for the JK. With this I mean the safe point where a JK can be tilted to either left or right side without falling and the same from the front when going up a steep hill. Just in case here is my JK info, 33s on the wheels, 2.5" lift.

If you have any idea or if you know that it is documented somewhere please let me know. I have been thinking about getting one of those things where you can see if the vehicle is way too much tilted and there is a chance of roll over.
 

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Hi everyone! I would like to know if there is any documented information about the maximum degree angles both vertical and horizontal for the JK. With this I mean the safe point where a JK can be tilted to either left or right side without falling and the same from the front when going up a steep hill. Just in case here is my JK info, 33s on the wheels, 2.5" lift.

Jeep used to publish that info...but I couldn't find it anywhere. On Google I found a thread that said a Jeep could handle a 40º side slope and a 60º climb.

With your 33's and lift, all that goes out the window. Also, I'd question those figures in light of terrain variances, tire grip on different surfaces, etc.

I'd say that once you get close to a 25º side slope, you need to start looking for a different path.

Or keep pushing till you roll...then you'll know for sure.
:D

If you have any idea or if you know that it is documented somewhere please let me know. I have been thinking about getting one of those things where you can see if the vehicle is way too much tilted and there is a chance of roll over.
An inclinometer (some peeps call it a Clinometer).

Here's a link:

Search Results - Quadratec
 

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I think what the op was asking is if anyone new what degree he could go to before flopping/rolling etc... Not the device that would tell him where he is at just my input :D :hide:
 

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I think what the op was asking is if anyone new what degree he could go to before flopping/rolling etc... Not the device that would tell him where he is at just my input :D :hide:

Um...you must have missed the red text in my reply there, eagle eye. :D
 

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With your 33's and lift, all that goes out the window.
This is an interesting topic to me. With my 4" lift and taller tires (35s), I'm raising the overall height of my vehicle. But with my 4.5" back-spaced wheels and wider tires (12.5"), my fancy Rubi is not only roughly 5.5" taller, but also 5.5" wider in stance. Also, my heavier tires must lower the center of gravity a bit (and they also are on the outer radius of the vehicle). Moreover, when I add skid plates (lower than the vehicle's COG), and even new heavier bumpers (probably have a COG lower than the vehicle overall), I'm lowering my COG a little more. Just wonder how that washes out in the end.
 

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MarineHawk,
when you start changing things on your vehicle everything is out the window. there's a lot of things that will decrease your roll angle including shifting weight and gas sloshing around in the tank.

If you want to know the actual roll angle of your vehicle I'm sure you could find out at a big off road venue. they have all kinds of flex ramps and I would imagine they can help you find the actual roll angle of your vehicle as it's outfitted now.
 

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Do you mean 40º & 60º or 40% & 60%? Those are pretty different.
Wish I could find the link I took that info from last night. Can't bring it back, though, no matter what search phrase I use. Anyway, I wrote it the way it was written. There was some discussion (this was an archived thread from another forum, and there was nothing but blocks of text) about the #'s...everyone agreed on the 40º...but there was some argument about the 60, whether it was º or %.

It was late and I was watching the Australian Open so I didn't agonize over it. Wish I'd saved the link now, though, but it was kinda like reading braille. :D

This is an interesting topic to me. With my 4" lift and taller tires (35s), I'm raising the overall height of my vehicle. But with my 4.5" back-spaced wheels and wider tires (12.5"), my fancy Rubi is not only roughly 5.5" taller, but also 5.5" wider in stance. Also, my heavier tires must lower the center of gravity a bit (and they also are on the outer radius of the vehicle). Moreover, when I add skid plates (lower than the vehicle's COG), and even new heavier bumpers (probably have a COG lower than the vehicle overall), I'm lowering my COG a little more. Just wonder how that washes out in the end.
Below is an automated spreadsheet for determining the specific COG and rollover angles for YOUR Jeep. Take the measurements required, plug em in, and the spreadsheet will do the rest. Random #'s are used in the examples...the blank spreadsheet is at the end of the document. It might scare you at first, but it's really not that difficult.


Center of Gravity and Roll-Over Angle - Jeepaholics Anonymous
 

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MarineHawk,
when you start changing things on your vehicle everything is out the window. there's a lot of things that will decrease your roll angle including shifting weight and gas sloshing around in the tank.

If you want to know the actual roll angle of your vehicle I'm sure you could find out at a big off road venue. they have all kinds of flex ramps and I would imagine they can help you find the actual roll angle of your vehicle as it's outfitted now.
Thanks. It would be interesting to find out what mine is once I get all the stuff on.
 

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Wish I could find the link I took that info from last night. Can't bring it back, though, no matter what search phrase I use. Anyway, I wrote it the way it was written. There was some discussion (this was an archived thread from another forum, and there was nothing but blocks of text) about the #'s...everyone agreed on the 40º...but there was some argument about the 60, whether it was º or %.

It was late and I was watching the Australian Open so I didn't agonize over it. Wish I'd saved the link now, though, but it was kinda like reading braille. :D



Below is an automated spreadsheet for determining the specific COG and rollover angles for YOUR Jeep. Take the measurements required, plug em in, and the spreadsheet will do the rest. Random #'s are used in the examples...the blank spreadsheet is at the end of the document. It might scare you at first, but it's really not that difficult.


Center of Gravity and Roll-Over Angle - Jeepaholics Anonymous
Thanks as usual Wolf. I'm sure you're right. I just remember falling for the degree vs. percent thing a while back when I wasn't paying attention. Those are some extreme angles if true. I used to drive Hmmvs near 40-deg back the day, and they're about 20 feet wide with an insanely-wide stance, and my knuckles were as white as snow.
 

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Thanks as usual Wolf. I'm sure you're right. I just remember falling for the degree vs. percent thing a while back when I wasn't paying attention. Those are some extreme angles if true. I used to drive Hmmvs near 40-deg back the day, and they're about 20 feet wide with an insanely-wide stance, and my knuckles were as white as snow.
I've read somewhere that around 25-30º you start getting into the "Pucker Factor" zone...40/60 seems insanely high to me.
 

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Discussion Starter · #12 ·
I think what the op was asking is if anyone new what degree he could go to before flopping/rolling etc... Not the device that would tell him where he is at just my input :D :hide:
You are right, what you said is what I'm asking. Thank you for making it clear, I had a hard time trying to figure out how to explain it.
 

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Discussion Starter · #13 ·
An inclinometer (some peeps call it a Clinometer).

Here's a link:

Search Results - Quadratec

I did not read the red text either, ha ha, sorry. I know that with my 33s and lift any documentation about this from jeep goes out of the window. However, it gives you an idea and with some math you can figure out what the new angles will be.

Terrain also has to be taken in consideration, just like you said, but this info helps such as if the max angle is 30 and I'm 20 but see ahead that the terrain will get me closer to 30 I can plan ahead and either take another approach if available or backup and forget about going that way.
 

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Discussion Starter · #14 ·
[URL="http://www.jeepaholics.com/tech/cog/" said:
Center of Gravity and Roll-Over Angle - Jeepaholics Anonymous[/URL]

NICE!!! I was about to begin searching for something like this! Thank you!
 

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Discussion Starter · #15 ·
I've read somewhere that around 25-30º you start getting into the "Pucker Factor" zone...40/60 seems insanely high to me.
I almost rollover once and since then when I find a similar situation I get worried. Pucker Factor when I almost rollover was 6, not more because I was able to stop the Jeep until the guys grab it to put some weight on the opposite side and get it straight again.

So, ever since that day, I always ask myself if I'm getting way to close to roll over. I'm not worried about me as I always wear my seat belt and the roll bars will protect me, ha ha ha, I just don't want to destroy my jeep.
 

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:whistling: An Inclinometer is a pleasant addition to your jeep--

It'll tell you when you can START to pucker, it'll make good pics (when focused) for bar bets, it'll EXCITE new passengers-, but

This one was close to 30° and "no pucker factors allowed", I've had my JKUR at just over 40° and that was pucker factor !




Your gut tells you what todo--even if you're going slow, a sudden rock on the upside, or "RUT" on the downside can change your "TILT" angle 1 to 10°-so

That and speed, is the main culprit for off-angle crawling danger, but

You've gotta secure ALL YOUR CARGO-- one shift of a heavy cooler/toolbox, will immediately incite you to step one, of roll recovery !

You may have seen my RAINGLER nets--

can'tbeatem

:dance::rofl: JIMBO
 

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I know this is an old thread, but still pertinent. I would say that those numbers are degrees. A 40 percent slope is arctan(40/100) = 21.8 degrees. A 60 percent slope is arctan(60/100) = 30.96 degrees.

I managed to put my 1.5" lifted TJ on 33" tires onto the edge of a slough by missing a corner on the "back driveway" and was sitting at 30 degrees plus a smidge and while it was pucker power, it wasn't "tippy" yet. I have been that far before parked in ditches. If the spec was 40 percent, I would have been more than 8 degrees past, which is almost 18 percent grade past and I'm sure I would have been "tippy".

30 degrees converts to tan(30)*100 = 57.7% grade.
40 degrees converts to 83.9% grade.

When they measure it, I picture going up a ramp with a strap anchoring the Jeep from rolling, but with a bit of slack until the Jeep takes up the slack because it starts rolling, but the ramp cheats it a bit. Using a lift on one side to make that side go up evenly front-to-back would be a better way. Keep in mind as people state above, you want to stay fairly well under that number because a rock on the high side, a dip on the low side, shifting load etc. can change the number drastically in an instant.

In my youth, I had a pickup sideways at the edge.. it was lifting the high side tires, so I had the passenger open the door to 90 degrees and lean until I could get it pointed downhill again. In retrospect, a really dumb idea if we *had* rolled, but it got us out of the situation.
 

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Circa 1967 I did a lot of off road motorcycle riding, and converted my otherwise stock 65 Beetle to a "hey-let's try the trail to the Pines" tavern event, coming in on a well known trail. All went well until once sidehill section that resulted in my buddy standing on the uphill door sill and me (well puckered of course) driving 100 yards mostly on 2 wheels and a promise to never try it again.

Don't know the side hill angle but my trusty crusty Gertenschlager (65 VW) kept me safe and entertained doing amazing off road antics that most sane people would have avoided.
 

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I may have a chance to take my JKUR on a 24* slope this week. I'll let you know how that goes. Of course, I'll be able to do it with some speed......
 

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Hope this forum doesn't consider this a necro, but I got my ZJ tilted enough to pucker last night.
I'm new to wheeling. Have a 2015 JK Wrangler so I bought an older Cherokee to mash with and I got about 25 degrees with a 3" lift on 32" tires. Steel bumpers and skid plates on this rig but this was the first time I've ever been in a vehicle where I felt like was going to fall out of the driver's seat into the passenger seat lol
Seems about 25 to me?
http://i.imgur.com/60rVhJk.jpg
 
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