What do you need to accomdate a 325 wide tire. Height aside. Because obviously for certain heights you would need a lift that will bring you up. But, for a wheel with 4.5-5.5 backspace. Whatest the widest tire people have run without spacers....backspace?

I'd like to keep this a width discussion.

 

Question add-on: 5.2 back space wheel, 325 wide wheel. How to fit?

 

There is no difference in clearance between a wheel with a particular backspacing, and a wheel with too much BS and a spacer to reduce the BS to the needed BS.

IE: A spacer merely reduces the backspacing so that you can keep the same rim, and still accommodate a wider tire.

The stock rims have 6.25" of backspacing....the more back spacing, the tighter the rim is tucked into the wheel well, covering the brakes more, etc.

The LESS BS, the further out the rim sticks...moving the rim closer to the fenders, and away from the brakes, etc.

The conversion between mm and inches is 25.4 mm per inch

So - a 325 mm section width tire is about 12.8" wide in section width.

Section width is not TREAD WIDTH...its just the sidewall cross section. The TREAD width can be more or less depending upon the specific tire, but is ALWAYS less than the section width, typically, by a good margin.

For example, a 325 mm section width tire that's 35" in diameter, would be about the same as your typical 35 x 12.5 sized nominal tire.

The BS required to fit a 12.5" tire is 4.5 - 4.75", with some able to clear with 5" of BS.

That means for a 325 mm tire, the 4.5" BS range is going to be about right.

TOO little BS makes the tire hit the fender on uptravel, TOO much BS makes the tire hit inboard wheel well components, etc.



So - if the rims have ~ 4.5" of BS, you do not need spacers....as you'd use the spacers to get the BS you want IF THE RIMS DO NOT ALREADY HAVE IT.

If you are running stock rims...THEN the 6.25" BS oem rims can fit the wider tires OK, but, the ties will rub on turns, etc...IE: They fit the RIMS, but they do not fit the JK.



On a stock set-up, about a 285 mm tire seems to clear on the oe rims....and spacers are used to keep the stock rims, and move the rims outboard to make more room, away from the inboard components, etc.

If you add a 1.5" spacer to the 6.25" BS rims, it reduces the BS to 4.75" (6.25" - 1.5" = 4.75")



So - if the question you are asking is if the rim HAS ~ 4.5" of BS, do you also need spacers, the answer is no...the rim is ALREADY BS'd about where you want it.

You COULD go wider with the same 4.5" BS'd rim, people are running 13.5's (~ 345 mm's...) in that range for example.

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Just saw the re-phrase...

OK, 5.2" BS is going to be too tight inboard...5" MAYBE, but 4.5 - 4.75 would be safer, for the 325 mm/12.8" section width you're looking at. (I'm assuming that your 325 mm WHEEL is supposed to be 325 mm TIRE)

 

I'm running 35-12.50-17 Nitto Mud Grapplers on 17 x 9 wheels with a 5" BS. The actual width of this tire is about 13" (should be about the same as your 325s, depending on the width of the wheel you're going to run). They don't rub unless you really stuff one of the rears up in the fenderwell, and then only slightly.

I'll be changing to 17x9 4.5BS wheels as soon as my new ones arrive.

I assume you mean 325 section width TIRE. That being said, you're going to be really close. I'm running the 4.5 RE long-arm lift, and for me there would be no way to run a 5.2" BS wheel because the rear tires would rub the trailing arms.

Hope this helps.

 

Man you guys are great. My first setup is going to be a 3/4" poly spacer in the front with a 33x12.50x20. After I lift, I might go with a 35x12.8x20 (aka 325 wide)


For my first setup....33x12.50x20 aka 305/55/20....and 5.1 backspace KMC XD Rockstars.....will I have a rub issue. From what you guys said, it should be close.

But we were talking about a 325 above, what about a 305.

 

Re-Read this.... the wheel choice I want also is a 5.1 BS and 12.5 section width. 305 mm.....it will be close, but cigar? or no cigar? Not much offroading.

 

The 305, 315 and 325 can all be the same size on the actual tire...technically, the 305 is closer to a 12" than a 12.5", but from tire to tire, that can vary.

The 5" of BS is still a good range for it.

Do you REALLY want to have to get a SECOND set of rims, etc...when you get new tires?



You could get ONE set, and use it for ALL the above tires.

 

No. I won't have two sets of rims. It will be a future purchase. I'm going to buy the first set (Rockstars 33x12.50x20 Cooper STT or Pro Comp Xtreme M/T)

When the tires wear out....I'm going to move up to a 35x12.8x20 or something like a 325/50/20....I might buy another set of wheels and sell the rockstars....Variety is the spice of life.

All these questions are for the boy scout motto....be prepared....


When and if I do go to a 325 with a 5.1 or 5.2 BS wheel...what is the thinnest/safest wheel spacer they make....obviously I'd like to get one that is
3/4". i I don't want to push the wheel out any further than needed.


Glad to here that a 5.1 BS with a 305 tire ....33x12.5x20...will fit decently. This way I just get my 3/4" poly spacer and enjoy it for a little with out a lift.


Teej

you've been real helpful with all this suspension/ wheel stuff. Can't thank you enough

 

LOL

There's always beer.



When its that close, I always recommend just driving it around for a while, and SEE what you need...there are so many variations between the NOMINAL/Labeled tire sizes, and the ACTUAL dimensions, that its really impossible to predict which YOU might have.

A good example was the post from a guy considering 37 x 14 tires vs 36 x 13.5" tires, of the same type...and telling him that the 36 x 13.5 tire was actually BIGGER in width AND Height than the 37 x 14" tire...its just like that, its the nature of the beast.

 

Well just from re-reading.....I'm going to need a spacer of .5-.75" for a 325mm wide tire with a 5.2 BS wheel. Question is. Do they make a .5-.75" spacer? are they any googd?