RedRockJKRubi

I was just talking with someone in regards to our club. He is thiking of letting longer wheelbase jeeps, run bigger tires then the shorter wheelbase jeeps.

So Im trying to figure out what size tire would put the wrangler unlimited, at the same break over angle as the standard length wrangler??

If the wrangler unlimited breaks over at 20.8 degrees, and the two door breaks over at 25.3 degrees. Then what size tires would allow the unlimited edition to break over also at 25.3 degrees?

Right now our club is only allowed to run a maximum of 33 inch tires. He just called me thinking maybe he should allow something a little bit bigger on the longer wheelbase vehicles.

Anyone able to figure out something I can't seem to at this moment?

Can someone layout some math?

Of course metric size tires are fine..

Thanks

Duke

What is the purpose of this limitation? What type of trails do you all have that this makes sense on?

The average vehicle I wheel with has 35-37" tires, with the occasional truck on even bigger.

And I believe you question is a geometry question, not algebra.

FRDesign

+1, What a Dumb rule.

And If I am Correct, You need a 2.6" bigger tire than the Stock 32" to have as good angles. That with no lift however.

If you get a 2" BB, you will need a 0.6" bigger tire in diametre.

So, a Teraflex 2.5" BB, and a set of 33" Tires will make it have better angles than a 2 Door.

00pumpkin

Most clubs give you a minimum tire requirement, not a maximum....................I would find a new club to wheel with.

bofer84

I asked this question a while back, its on here somewhere...Anyway, yea a 2.5" budget boost will give you much better break over angle...however, going with a 35" tire and a 3" lift is right where you want to be

RedRockJKRubi

Well i did figure out the answer through my cousin who is very good with angles. He figured out that It would take another 1.1" of ground clearance to climb that same angle as the two door wrangler in stock form.

Anyways, the president who runs the club has been doing it for about 25 years, and has started 4 other clubs in the area. But as they got very political and increased the tires sizes, he left and started something else.

He likes to keep a maximum of 33" tires, as it makes it a little tougher to wheel, and more tricky. It also makes the owners feel more comfortable about theyre land that they let us wheel on, seeing a rather stock, not to overly modified vehicle , verse a rock buggy with 44" tires. Less worry about doing any sort of rutting or damage.

It also some people with less money, or who dont want to run a big rig to run the same trails as someone with 33" tires. Someone with 38" tires could do something someone with 31" tires wouldn't even think about doing.

We typically run Class 5-9 roads. Some of them definetly require winching no matter what size tires your running.

I would personally like to run atleast a 35" tire with littler lift verse a 33" tire with more lift to get clearence.

(I have everything i need to eventuallly do and air-lift setup when i get the time, A whole 8" of lift if needed)

So if a two door wrangler in stock form with 32" tires can do an angle of 25.3 degrees before bottoming out. If you put on slightly larger then a 35" tire onto an unlimited edition stock height you could climb that same hill without bottoming out, though I think we all know that a 35" tire wont fit under a stock height wrangler without special aftermarket fenders or some lift.

gjeepguy

it looks like you would have to run a 42 inch tire on an unlimited in order to maintain the 26 degree breakover angle that a 2 door with 33" tires has.

Version-7

That does not take the lift into account....

With the increase in the lift the size of tire can be decreased.

Not good at math but 3" of lift + 3" of Tire (1.5" of lift) equals a 4.5" increase in height for the Frame.

With a 20" Wheel base difference and a 4.5" increase in height should get you pretty close to the same angles as a stock 2 door.

The important thing however.... is you will be:
4.5" higher than a stock jeep.
Improved approach angles
Imporved departure angles
Improved Breakover angles
and generally be a more capable vehicle off-road.

FunN4Lo

x2. That is just kinda silly.

Then again I have no idea about math.

Version-7

Got this form a Post "Ghostship" made on another thread:

"
The straight mathmatical calculations give these results for the JK Unlimited:

Base Model.....31” Tires, no lift.....BOA 17.8 degrees
Rubicon...........32” Tires, 1” lift.....BOA 20.8 degrees
Mod 1..............33” Tires, 2” lift.....BOA 25.6 degrees
Mod 2..............35” Tires, 3” lift.....BOA 31.3 degrees
Mod 3..............36” Tires, 3.5” lift..BOA 35.2 degrees
Mod 4..............37” Tires, 4” lift.....BOA 37.3 degrees

Of course, since each lift and tire give a different real-world height, individual results will vary slightly.

"

So it loooks like 3" + 35" is the way to go.

This ofcourse does not change the fact the your wheelbase is longer. A 4 door will never be able to go everywhere a 2 door can. The size of the vehicle is just larger. Turning Radius is Larger. etc...