Need advice on rim size.

[kj924]

I have been thinking on getting a set of soft 8's for the Libby. So, I don't know what width to get 7" or 8"???? Backspacing of 4" or 3.75" ?

I want to go 15" on the soft 8's. Any advice??

 

[ATXKJ]

Virtually any tire that will fit under a Liberty will be better on a 7" rim than an 8"
- check Tirerack's recommended rim sizes - the 8" are really better for 265 and wider.

not sure about the backspacing - I'm thinking 4"

 

[J-Thompson]

you need 4" or more of back spacing
and even then with the lift you have you will have to run a smaller tire than what you have now
local KJ has the same lift and rubs with 30 X 9.5's on a 15 X 7" wheels with 3.75" B/S
your tires now are a full inch taller than those

I say keep what you got

 

[tjkj2002]

Tires 265's(or 10.50's) or smaller will work much better on a 7" rim then a 8" rim,way better if you plan the wheel it.Keep the BS between 4"-5".

My 265/75"s are stamped on the sidewall to mount on a 7" rim.

 

[kj924]

Right now I am running 245/75 16's, but I plan to go to 15's with the soft 8's.
What size is comparable in 15"?

I guess the question is , would I be safe running a 31x10.5x15 or even a 33x10.5x15? I think 33" would be pushing the limits.

 

[tjkj2002]

Right now I am running 245/75 16's, but I plan to go to 15's with the soft 8's.
What size is comparable in 15"?

I guess the question is , would I be safe running a 31x10.5x15 or even a 33x10.5x15? I think 33" would be pushing the limits.

You'll never fit the 33" tires.a 245/75R16's is equal to 30x9.50x15's.

 

[kj924]

Cool.....Thanks man!

 

[J-Thompson]

I pulled some specs on the MTR's to show you what sizes compare
30 X 9.5 R15
OD=29.8 Sec=9.5
31 X 10.5 R15
OD=30.7 Sec=10.5
32 X 11.5 R15
OD=31.5 Sec=11.4

225/75 R16 *(this size was taken from a BFG KM not the MTR)
OD=29.5 Sec=8.8
245/75 R16
OD=30.7 Sec=9.8
265/75 R16
OD=31.7 Sec=10.5

The Section is the widest part of the tire and this is where running 15" rims will kill you
if you take the 245/75 which has the same OD as a 31X10.5 but is near 3/4" narrower
now the 245/75 fits and does no damage when stuffed but is close
and I know this from the wheels I have with 5.5" of B/S
that 3/4" extra width adds only 3/8's on each side but add also 1"+ from the wheel and you are adding about 1.5" to the out side of the tire
That would rip the fenders right off of my KJ

you need to decide what you can live with
I have seen a KJ owner DESTROY both his rear fender flairs and do some good damage to his tires with the same lift you have and running 30X9.5 BFG MT's on 15X7" wheels with 3.75" B/S
if he had 31's he would A) no longer be able to open his rear doors and B)be out of 2 tires because the sheet metal would have ripped the side walls

I would suggest you go flex out your rig and crunch some number
if you can not fit you hand between the tire and sheet metal then adding any size to the tires or changing rims will be bad