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Personal opinion, but I wouldn't run a 10" wide rim with a 12.5" wide tire. A 8" wide tire will hold the bead much better, especially when aired down wheeling.

 

You want a 3.5" - 4" BS on the MJ's with a 12.5" tire. The lower the number, the further they will stick out.

 

Good thing I asked, I guess. The spec sheet for both the 33x12.5 and 35x12.5 Bighorns list a 10" wide rim. But 8" does make sense for the reasons you listed.

 

So 15x8 Cragar Soft 8s with 4" backspacing should be a good choice, right?

 

Would rim width affect the 3.5"-4" measurement for backspacing?

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We recommend running the Bighorns on a 8" wide rim. With an 8" wide rim your going to want to run the soft 8's in the 4" BS flavor. We've NEVER broken the bead with a 33" or 35" Bighorn on a 8" wide rim aired down as low as 12psi wheeling. We typically run them at 18psi though on the trails and they perform very well.

 

And yes, if you were running a 10" wide rim the BS would be different.

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100% agreed...8" wide is the way to go. 10" wide is just too wide for the 12.50 tire unless it is just for looks and not goingto be aired down & wheeled.

 

Personally, I thought it was 4" BS for the 10" wide wheels and 3.68" or 3.75" BS for the 8" wide wheels. The 10" will need to be pushed out a little more than the 8".

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Personally, I thought it was 4" BS for the 10" wide wheels and 3.68" or 3.75" BS for the 8" wide wheels. The 10" will need to be pushed out a little more than the 8".

I must take this back as I realized after posting it that I have it backwards... :oops:
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Personally, I thought it was 4" BS for the 10" wide wheels and 3.68" or 3.75" BS for the 8" wide wheels. The 10" will need to be pushed out a little more than the 8".

I must take this back as I realized after posting it that I have it backwards... :oops:
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  • 1 month later...

Since it seems my wallet will like 285/75R16 a little better than 33x12.5R15, and they are still 33", but an inch narrower, I did some math.

 

If my math is correct, the inside of the tire should be pretty much in the same place for the following two:

33x12.5R15 on 15x8 rims, 4" backspacing

285/75R16 in 16x7 rims, 4" backspacing

 

Would that be correct? The 285 is about 1" narrower, and with the same backspacing the 1" narrower rim would sit in 1/2" more.

The outside of the tire would stick out 1" less with the inside of the tire in the same spot. I think.

 

33x12.50R15 tire $175, rim (Cragar soft 8 ) $45, times 5 = total $1100

285/75R16 tire (retread) $130 shipped, rim (Cragar soft 8 ) $60, times 5 = total $950

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Friends don’t let friends run 15 X 10’s. Your jeep will look like one of those hillbilly CJ’s!!! For a 12.50 wide tire just run 8” wheel. For the back spacing I just run the ol black wheels. I can't remember what the BS is off the top of my head. But yull be fine! :banana:

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