Why do people think an XJ is more likely to tip over?

[xj_mike]

Okay, let me explain. I had been looking at different ways to mount the spare outside the vehicle, either a roof mount or swing away rear mount. One thing I keep reading is how putting a rack on teh roof or mouting the spare up there makes the XJ so much more prone to tipping over when wheeling. Yes, I have no problems understanding the raising the CG and such. I get all that. What I am curious about is, look at a lot of Land Rovers. You'll see spares up there, big racks, even the traction plates you put down to help you get unstuck. With all this stuff up there and being taller then an XJ, you would think they would be worst but you almost never hear anyone say anything about these setups. Look at the rigs in the Camel Tourist Trophy events and the likes.

Why is it okay for a Land Rover (or Range Rover) to have these big roof setups but XJ are like "going to tip over"?

Comments??? Just curious BTW.

 

[91xjrunner]

i agree i have never got that, my only guess is that the XJ is smaller/lighter than a rover

 

[IntrepidXJ]

all depends on the kind of wheeling you do. not the vehicle.

 

[needsrepair]

I guess it would also depend on the design differences. I looked under a guys 2005 rover and was surprised to see how seemingly "old fashion" it was. It had a driveshaft parking brake. Makes me think there is more iron down low? Not sure but as you say it is interesting. I wonder what the wms to wms is compared to a xj. I also have your same concerns when I lift mine and go to full size spare. One thing that will help is changing the backspace. Sure are a ton of things to consider in all this lift/tire stuff. Like a woman shopping for shoes

 

[5-90]

Probably because people get programmed to drive a certain way - when they try to drive a truck like a low-slung roadster, they're going to get into trouble.

Doesn't matter that it's their fault for driving the wrong way - they blame it on the vehicle. Doesn't matter that they were trying to use the vehicle well outside it's design parameters, either.

ANYTHING can be flipped over, if you try hard enough. I saw someone on a windy road manage to flip over a Corvette - even those have limits.

Go ahead, put your tyre on the roof. As long as you're mindful of the fact that it's up there, and drive accordingly, you'll be fine.

ALWAYS be aware of the limitations of your vehicle!

5-90

 

[DaffyXJ]

Another consideration is the unbody. To lift the Xj it is all suspension lift. Even a Rover has a frame. So it's possible to lift a rover to fit 33's or 35's with less suspension lift than an XJ. Hence we work at ways to cut the cherokee up to fit tires and keep it low. When I was at 8 inches with 35's with all the upper weight, the XJ WAS tippy. anything over 30 degrees elevated the pucker factor significantly. Toss in a tight suspension and a higher CG and you're in trouble real fast. I've flopped mine once and came as close as you can without going over three other times in the last two years.
Of course if you're just on the fire roads or green trails no problem.

 

[safn1949]

Remember that the Land Rover is very heavy also,over 5000 lbs empty:cheers:

 

[GSequoia]

A spare tire on the roof isn't going to make you flip over. That's flawed logic that runs rapent on the Internet, such as the doors being structual items.

Now me I'd never run my spare on the roof only becuase it would be such a pain in the ass to get up there. I wouldn't want to do it with a 31 let alone my 35's I have now!

 

[nitrogt101]

Here's a good article I read about center of gravity and how far is too far. It gets into the technicalities of it if you're interested.

Jeepaholics.com

 

[Fryphax]

I have enough trouble lifting my 38s to mount them, I wouldn't want to think about trying to get it onto my roof or off of it.

 

[xj_mike]

Here's a good article I read about center of gravity and how far is too far. It gets into the technicalities of it if you're interested.

Jeepaholics.com

Wow! Brain exploded from that page! Lots of good info but wow!

 

[in2fords]

with the wheeling we do here we almost flop all the time, generally we have to have a spotter jump on the corner just so we dont go over, and thats just on the road to get to the real fun areas!!!! if I tossed a 33 on my roof I would be afraid of taking a turn on the road, of course with no sway's and soft springs I worry anyway.

 

[98XJSport]

Older jeeps were narrower, shorter, and tippier. Most people that aren't in the know that Ive talked to equate jeep with tippy. Even new jeep wannabe models.

 

[SanDiegoXJ]

Seems to me like it's pretty self explanatory to be completely honest....

Sling an 80lb weight on top of your vehicle and it will not be as stable on off camber situations than a vehicle with a lower CoG...makes sense, right?

As for why do Land Rovers have their tires mounted up top, well that goes back to someone's bright idea about the kind of wheeling you do. Land Rovers have been mostly designed with the intention of safari like off roading. Generally used in open flat terrain and water crossings, unlike a Jeep which was designed for a more all-around off-road capability and most recently the central figure of the rock crawling crowd (aside from the hybrid buggies).

Personally, I've only seen a few land rovers on rocky trails and they're generall getting pulled over an obstacle by a Jeep. In swamps, the Land Rover seems to do much better tho. I imagine they'd also shine in deserts and plains. But with their limited flexibility, they become pretty tippy as they are...that itty bitty tire on top isn't gonna do much to change that.

And even then, most the Rovers I have seen with external mounted spares had them on the hood, not on the roof.

 

[Cottontail]

Interesting passages, from Chapter 9 of the book High and Mighty SUVs: The World's Most Dangerous Vehicles And How They Got That Way by Keith Bradsher. It is a long read, but I found it interesting.

SUV's roll over with particular frequency: 5 times per 100 crashes compared to 3.8 times for pick ups, 2 times for mini vans, and 1.7 times for cars.

Intrequingly the Jeep Cherokee and Jeep Grand Cherokee have low rates of rollovers. They also happen to have fairly unsusual underbodies. Both Jeeps have very thick frame rails like a traditional SUV, but neither is built on a picup trick underbody. Indeed, neither vehicle is assembled with a body on frame approach at all; both have unit bodies, with the roof, sides, and underbody all welded together into a unit.

...the Cherokee and Grand Cherokee each have very low rolloer death rates by SUV standards.

The roll over death rate for a Jeep Cherokee is barely higher than for a car, and the Jeep Grand Cherokee's rate is almost as low. Even now,nearly 2 decades after the Cherokee went on sale, no automaker had been able to design a small or midsize SUV with anywhere near as low a rollover death rate as the Cherokee. Onlt the larger SUVs...have similar rollover reates to the Cherokee, simply because they are so big and heavy.

...nobody has figured out why the Cherokee is so stable...center of gravity is only slightly lower than in other SUV's, and it is not especially wide. Yet is stays on all four wheels practically like a car.

In 1999...drivers of four wheel drive Cherokees died in rollovers at a rate of just 15 per million registered Cherokees, according to insurance-industry calculations...drivers of the bigger midsized SUVs with four wheel drive have an average rollover death rate of 39 per million registered vehicles.

...the Jeep Grand Cherokee has a rollover death rate per million registered vehicles of just 36 for the two wheel drive model, and 23 for the four wheel drive model.

American Motors was haunted in the early 1980's by cost of Jeep rollover litigaton, and...subjected the Cherokee to the extremely demanding tests that Renault used in Europe.

...the safety record of SUVs actually improved though the 1990s, to the point that SUVs became practically as safe as cars. For every million registered SUVs on the road in 2000, there were 134 occupants killed in crashed of all types, including those not involving rollovers. The occupant death rate was barely lower for cars, at 126 per million.