[sgracida]

Hello everybody what's is the back space need it to fit 35/12.50/15 on 8" non expensive wheels? (Black Mountain) perhaps?


My Jeep is a 93 YJ on 4" inch lft and working on lift shackles and 1" body lift or maybe more.

Thank you everybody

[+Crusader+]

Without rubbing the leaf springs on an 8" wheel you will want about 3" of backspacing ...
That is an uncommon backspacing for that size, so unless they are building a custom bs for you, you are better off getting 10" wheels with 3.75" backspacing.

[sgracida]

Originally Posted by TheHoff

Without rubbing the leaf springs on an 8" wheel you will want about 3" of backspacing ...
That is an uncommon backspacing for that size, so unless they are building a custom bs for you, you are better off getting 10" wheels with 3.75" backspacing.

I just planning to use my rig on the desert sand dunes and rock crawling, is this 10' wheel going to affect my off road capabilities?

I know that having 10" rims is not to good for rock crawling but how bad it would be from a scale of 1 to 100%

Thank you!!

[sgracida]

Originally Posted by TheHoff

Without rubbing the leaf springs on an 8" wheel you will want about 3" of backspacing ...
That is an uncommon backspacing for that size, so unless they are building a custom bs for you, you are better off getting 10" wheels with 3.75" backspacing.

One of the reason that I want bigger tires is because a friend of m ine gave me a complete motor from a 1993 mustang v8 and I think that those tires would be perfect for the power that my jeep is going to have.

Now the Jeep has 31" tires and that is why I want to 35" to go 4" more in tires just like my lift.

iam installing shackels 1" lift more and 1" body lift to compesate the tires. Please give me your advice what should I do?

[rustywrangler]

I would get a 3.5" BS and an 8" rim. You do not need a 10" rim.

[KarenCaren]

Originally Posted by rustywrangler

I would get a 3.5" BS and an 8" rim. You do not need a 10" rim.

I totally agree with this one. You don't need a 10" rim. You can fit that tire with 3-4" BS and 8" rim.

By the way, that is one nasty motor you have.



_____________
If you ain't first your last!
truck parts

[sgracida]

Originally Posted by KarenCaren

I totally agree with this one. You don't need a 10" rim. You can fit that tire with 3-4" BS and 8" rim.

By the way, that is one nasty motor you have.



_____________
If you ain't first your last!
truck parts

Thank you for your help and oh yes I can wait to install that motor on my little jeep. Im not ready yet still doing research.

[sgracida]

Originally Posted by rustywrangler

I would get a 3.5" BS and an 8" rim. You do not need a 10" rim.

/
Ok, that means that 3.5 BS with 35. 12.50 15 is going to be just perfect right?

Thank you for your help

[+Crusader+]

Originally Posted by KarenCaren

I totally agree with this one. You don't need a 10" rim. You can fit that tire with 3-4" BS and 8" rim.

This is completely false ... or absolutely misleading I should say.

He could also fit those 35's on an 8" wheel with 5.5" backspacing, but the main issue is: at what point in turning the wheels is the tire going to rub the leaf spring? 4" backspacing on an 8" wheel and a 35 will rub every time, as it will on an 8" wheel with 3.5" ... but don't take my word for it, buy the wheels and find out on your own.

An 8" wheel with 3.5" bs is equivalent to a 10" wheel with 4.5" bs ... both would place the tires centerline the same distance away from the body. As sure as the sky is blue, a 35 mounted on a 10" wheel with 4.5" bs will rub before you get to full steering lock ... so why wouldn't it also hit on an 8" wheel too, which actually slightly increases the tires OD too just to throw more reality into the mix. Anyhow, question remains?

[rustywrangler]

Originally Posted by TheHoff

This is completely false ... or absolutely misleading I should say.

He could also fit those 35's on an 8" wheel with 5.5" backspacing, but the main issue is: at what point in turning the wheels is the tire going to rub the leaf spring? 4" backspacing on an 8" wheel and a 35 will rub every time, as it will on an 8" wheel with 3.5" ... but don't take my word for it, buy the wheels and find out on your own.

An 8" wheel with 3.5" bs is equivalent to a 10" wheel with 4.5" bs ... both would place the tires centerline the same distance away from the body. As sure as the sky is blue, a 35 mounted on a 10" wheel with 4.5" bs will rub before you get to full steering lock ... so why wouldn't it also hit on an 8" wheel too, which actually slightly increases the tires OD too just to throw more reality into the mix. Anyhow, question remains?

I think you are missing the point of a few posts here. We are simply stating he doesn't need a 10" wide rim to run 35's.

And a 10" wheel is going to rub sooner than an 8" wheel, not because of tire center line, but because it moves the tires side wall out further than on an 8" wheel. I saw this all the time when working as a tire tech.

[sgracida]

Iam confuse!!!



What happend with 33 12.50 15 is going to be the same?

[CB3]

I don't know much about YJ fitment issues. I only know XJ and TJ/LJ fitment. So I can't help with YJ fitment, but I do know a few things about 12.5" wide tires on an 8" wide rim vs a 9" wide rim or 10" wide rim with regard to how the tire and rim fit each other and perform, and how that affects air pressure and contact patch.

While a 10" wide rim wouldn't be as good for rockcrawling over giganto boulders, it would be just as good for sand IMO, and better on road for air pressure, contact patch, tire life, and wet pavement traction. To bad you can't get a 15 X 9 rim and split the difference? Though I'm not sure about clearing the leafsprings on a YJ.

Having said the above, I have no idea what rim would be best for fitment of a 35 X 12.5 R15 tire on a YJ because I'm not familiar with YJ fitment issues (causes by front leaf springs).

However, I do know that some brands of 35 X 12.5 R15 tires run a bit narrower than advertised and are really 35 X 12 R15 tires (which would help you fit it). Some Cooper and some Cooper subsidiary brands (Mickey Thompson for one) tend to run narrow like that. I said some. Others don't.

Also, the Goodyear 35 X 12.5 R15 tend to run a bit narrow at around 35 X 12 R15. Like the MTR for example. I wonder what's the situation with the Dunlop Duratrac? Since Dunlop is a Goodyear subsidiary, it's possible that it might also run narrow in that size.

Any tire in that size that runs a half inch narrow like I described above would slightly help the fitment issues.

[CB3]

Originally Posted by rustywrangler

I think you are missing the point of a few posts here. We are simply stating he doesn't need a 10" wide rim to run 35's.

Agreed ^ assuming he can find an 8" wide rim with appropriate BS. If he can't find that due to availability issues, then maybe a 10" rim would be better if it's available in appropriate BS (after taking into account that a 2" wider rim moves tire out 1" before considering BS).

Originally Posted by rustywrangler

And a 10" wheel is going to rub sooner than an 8" wheel, not because of tire center line, but because it moves the tires side wall out further than on an 8" wheel. I saw this all the time when working as a tire tech.

I don't follow your logic there. A 10" wide rim (if same BS) will move the tire out 1" farther from the leaf springs than an 8" wide rim would. Wouldn't it?

So that would be moving the tire farther away from the leaf spring. Wouldn't it? So more clearance to leaf spring. Right?

How come you said the 10" rim would make it rub sooner? I don't understand why you think so. Being farther out might/would make it rub the flare sooner though, I could understand that.

But YJ aren't my thing. So maybe there's something I don't understand here.

[rustywrangler]

Originally Posted by CB3

How come you said the 10" rim would make it rub sooner? I don't understand why you think so. Being farther out might/would make it rub the flare sooner though, I could understand that

With an 8" wide rim and a 10" wide rim using the same size tire and same backspacing, making it the same on the inside edge for both, the 10" wide rim would push the side wall out more than the 8" wide rim. It is hard to explain without a visual picture. I am trying to find something now.

[+Crusader+]

Sidewall ballooning doesn't matter regarding leaf springs that I have ever heard of??

The parts on a YJ that I am aware of rubbing are either A) the tire moving up into the flare/fender lip upon suspension compression on an obstacle, or B) the inner corner of the tread lugs rotate inward and contact the leafspring while turning the wheel close to full lock. I don't see what else would get in the way, unless he was running so much bs that the tire was turned less than an inch and hits the leaf ... In this case, yes ballooning would matter, but would be irrelevant because he's got too much bs to begin anyways, and if the sidewall didn't hit first, the inner corner of the lugs would just as easily.

I do agree about not "needing" to run a 10, and I would rather use an 8" wide wheel over a 10" myself ... BUT seeing as how nobody I know of makes an 8" with 3" or < bs (aside from Eagle Alloys that come close with their typical 3.25" bs'd wheels) I with my YJ would be forced to use a 10" wide wheel with 3.75" backspacing. Running 35's on a factory configured YJ suspension is a compromise, that is just the way it is. Sure you can always put washers under the steering stops on the axle to limit turning radius, but I would rather run 33's on an 8" wheel with 3.75" bs. Most trails around me don't require more than 33's and 3+ inches of lift to get through them. Lockers do more for you than the extra 1" of ground clearance gained by going to 35's. I also prefer a tighter turning radius.

The thing that bothers me is not whether or not he does or doesn't need a 10" wide wheel to run 35's ... I never argued that point ... I only argue what is readily available from wheel manufacturers and what wheels he can buy to avoid rubbing while steering. Naturally rubbing on compression is another can of worms that takes into account lift, flares, fenders, bump stops, shocks, etc etc ... so that is all stuff that can be fine tuned ... I just don't think he should go buy wheels and come to find out he's rubbing in the areas I discussed since my first post ... I don't like playing with other people's money that way.