CJ wheel size and backspacing?

[baddiesel]

Folks, I've wore-out the search function, and didn't locate exactly the correct info on backspacing. I've found a "I think" a great deal on (5) black rugged ridge rims for $289.00. They're 15x8, 5 on 5.5 pattern, with 3.75" backspacing. I tried to measure my existing wheels with a tape measure. The best I could approximate is: 15x10's. Worn-out tires are: 31x10.50x15". I would like to know if the backspacing is correct for my CJ?. I do not intend to mount bigger tires than the 31x10.50's, and I do not want this Jeep any higher. I don't even know if it has a lift kit or not. Any help with the backspacing info would be greatly appreciated, thanks!

 

[Old Dog]

That is the "standard" back spacing, it would be hard to find anything different. They should work fine.

 

[mylittlecj5]

I'm betting your original wheels are 15x7 or possibly 15x8, not 15x10. Those would be a really wide rim for 31x10.50s.

 

[TroyaCantrell]

Those should fit just fine. You don't want 10" rims with 10.5" tires, max rim width on that tire should be about 9" 8" is even better. Since that rim is an off the shelf Jeep rim you should not have any trouble. Where you have to really watch is where you are shopping by just rim size and not something specific for your year make and model. You not only have back spacing to consider but also offset and bore. But again that RR rim is for a Jeep up through the mid '80s I think.

The 8" rim will allow you to air down the tire for off road use. When you shop tires check the real size of the tire, not all 31 x 10.50 tires are actually 31" tall or 10.5" wide. The different rim sizes will also change the size a bit. If you put 31s on say a 19" rim vs a 15" rim there will be less compression of the sidewall in the 19" making the stand a bit taller. The wider rim has a similar affect spreading the inner lip.




Troy--
Steering rehab- http://www.jeep-cj.com/forums/showthread.php?t=4106
Build thread- http://www.jeep-cj.com/forums/f98/1966-cj-6-build-15075/

 

[baddiesel]

Thanks to all for your comments and info. I will be purchasing the rugged ridge black rims. I just can't beat that (5) rim package deal. Happy New Year to everyone!!!

 

[Saddle Tramp]

The other thing to remember about rim size in relation to the tire width is the protection of the rim itself. By using a tire wider than the rim the “bulge” of the sidewall (aired down or not) helps keeps rocks from catching the edge of the rim and either bending or breaking it. (OEM CJ rims would have been 7” x 15" at best except for the Golden Eagle package which were wider.)

 

[baddiesel]

That's good to know info, thanks. I think I'll be okay with mounting 31 x 10.50 x 15 on these rugged ridge 15 x 8's. I'll verify the tire dimensions. They're Falken AT's.