another stupid QUESTION

[SANDBLASTER]

What the heck is back spacing in regard to rim selection and what effect does It have ??? What do I need to know about this when I am choosing a new rim?...

 

[BajaEdition]

Before going into a long and complicated post trying to get as much info as possible into a confined space
let me just direct you here

https://www.rsracing.com/tech-wheel.html

ps, no question is stupid, not asking a question is stupid,

 

[BrockGrimes]

Here ya go:

 

[BrockGrimes]

Basically back spacing is the distance from the edge to the mounting surface.
The more negative back spacing the more the wheel will stick out away from the vehicle, however this also puts stress on the axle.

Ideal is to have no negative or positive, the wheel mounting surface will be centered
and you'll have less strain on the axle.

 

[SANDBLASTER]

Basically back spacing is the distance from the edge to the mounting surface.
The more negative back spacing the more the wheel will stick out away from the vehicle, however this also puts stress on the axle.

Ideal is to have no negative or positive, the wheel mounting surface will be centered
and you'll have less strain on the axle.

SO? Is there a preferred back spacing for a rim on a 81 CJ7 narrow trac going to a 33x1250x15 tire ? example 3.75 BS on a 5 on 5.5 15x8

 

[IOPort51]

Do you have options?

SO? Is there a preferred back spacing for a rim on a 81 CJ7 narrow trac going to a 33x1250x15 tire ? example 3.75 BS on a 5 on 5.5 15x8

 

[SANDBLASTER]

Do you have options?

Not sure what you mean.

 

[Sasquach]

A 4" backspace is as close as you can get to your calipers assuming disc brakes. Up to 31" tires and you will be good on lock to lock clearance with your leaf springs. Going bigger on the tires will mean you need less backspace to move the tire out farther for clearance.
If you are going with 33x12.5 you will want less backspace than 4" say 2-1/2" but trying to find the wheels you want with those numbers tough, you may have to then think about wheel spacers to gain tire clearance.

 

[IOPort51]

how many different back space dimentions do wheel manufacturers give you on an 8" wide wheel? If stock is 4" I would say you will not be able to have more with out dragging the tire and depending what width the new tire is, say 2" wider than stock, you may want less back space, 3" perhaps. this way all the additional rubber moves away from the wheel well to keep the inside edge close to the original position, relitive to the wheel well.

 

[SANDBLASTER]

how many different back space dimentions do wheel manufacturers give you on an 8" wide wheel? If stock is 4" I would say you will not be able to have more with out dragging the tire and depending what width the new tire is, say 2" wider than stock, you may want less back space, 3" perhaps. this way all the additional rubber moves away from the wheel well to keep the inside edge close to the original position, relitive to the wheel well.

OK! so I'm not the sharpest knife in the drawer BUT ...
will the 3.75 inch BS work with the 33X1250X15 tire on my 1981 CJ7

 

[IOPort51]

what was the width of the stock wheels and what was the back spacing of the stock 7" wheels? I did not look at the profile so , do you have any lift?

OK! so I'm not the sharpest knife in the drawer BUT ...
will the 3.75 inch BS work with the 33X1250X15 tire on my 1981 CJ7

 

[SANDBLASTER]

what was the width of the stock wheels and what was the back spacing of the stock 7" wheels? I did not look at the profile so , do you have any lift?

3 INCH LIFT, CJ STOCK WHEELS with 31x1050x15 tires and 4inch BS BUT I THINK THEY WERE 15X8 RIMS

 

[IOPort51]

when you turn what you have right now lock to lock do you have any clearence at all ? I would hope you had at least 2 inches with what you have.

3 INCH LIFT, CJ STOCK WHEELS with 31x1050x15 tires and 4inch BS BUT I THINK THEY WERE 15X8 RIMS

 

[Sasquach]

OK! so I'm not the sharpest knife in the drawer BUT ...
will the 3.75 inch BS work with the 33X1250X15 tire on my 1981 CJ7

No, tires will rub the springs.

 

[SANDBLASTER]

when you turn what you have right now lock to lock do you have any clearence at all ? I would hope you had at least 2 inches with what you have.

NO problem plenty of clearance

 

[IOPort51]

defign "plenty", numbers work well preferably associated with inches.

NO problem plenty of clearance

 

[SANDBLASTER]

No, tires will rub the springs.

Don't want to hear that bad news... are you sure?

 

[SANDBLASTER]

defign "plenty", numbers work well preferably associated with inches.

in reference to front tire or rears

 

[SANDBLASTER]

in reference to front tire or rears

DON'T give up on me yet I'm getting there

 

[Sasquach]

Don't want to hear that bad news... are you sure?

33x12.5 on stock wheels will rub...Possitive. As I allready said you could add wheel spacers to gain clearance and yes we are talking about the front.

Mine rubbed bad with 33's but has clearance on 31's. both mounted on stock 15x8 w/4" backspace.
PO had 1-1/2" wheel spacers to get turning clearance with the 33" tires.