Wheel Backspacing and Offset Info

I think factory is 4.5bs. Or 4

 

Ok, I need help in purchasing my first ever set of wheels.

I have a LR UCAs and a 3" OME lift kit with a AAL in the rear sitting in my garage waiting to be installed.

This is the wheel I am planning to get:



18" x 9"

At that size, it is available in a 0 offset and a 5" backspacing.

Does anyone know if I would have any issues with:

265s or 285s?

Still havent decided on a tire size, just seeing what could be done.

Please offer suggestions or ideas.

 

The smaller number the BS, the more the wheel/tire is pulled away from the suspension..

 

Yr good with 265's

 

265's no problem...any 33" tire is gonna require some trimming, mud flap removal, and maybe a CMC depending if you have adjustable UCA's which can help you with more clearance..

 

Thanks for your help.

How do I know if my LR UCAs that I bought are adjustable?

Again, this is my first truck and first time buying any of this stuff.

Thanks!

 

Your LR UCA's are adjustable, check out this link for some more info, I strongly recommend if you dont know how to wrench on suspensions to take it to a shop, or get help from someone who has, you will need a good alignment after the install..!
http://www.tacomaworld.com/forum/suspension/137350-light-racing-uca-install.html

 

I have experience changing stock for stock parts on vehicles, but thats it. Nothing custom, or "upgraded" parts, if that makes sense.

I will have an experienced shop do this for me.

 

alright, right now i have enkei rims that are 18x9.5 with +15 offset wrapped in 285 65 18 firestone MT's. i used to rub my UCA's, but i installed spc light racing UCA's and that stopped the rubbing.
i just ordered some ultra 189U rims, and they are 18x9 with +12 offset.
i dont like the wider stance, i want it narrow and tall (like i have it now)
will this fit? (the ultra 189U's i ordered)?

 

Can someone explain offset to me. Cause I'm wanting to put a 18x8.5 rim under a stock height truck wanna try keep the tire from sticking out as much as possible

 

Offset is how far away from rim center the hub mounting surface is.
Backspacing is how far away from the rear of the rim the hub mounting surface is.

Take the nominal rim width and add 1" to calculate.

So an 8.5" rim is considered to be 9.5" wide.
4.75" backspacing will give 0 offset.

Offset is commonly given in metric.
Positive offset is when the rim is pulled in toward the frame.
Negative offset is when the rim is pushed out (mounting surface behind the rim centerline)

But be careful. Excessive backspacing will cause the tire to rub the control arms or the frame.
Insufficient backspacing will cause the tire to rub the fender.

 

So dose a negative offset = lip on a wheel? Or is it how far your tire stick out or in?

 

The more negative offset, the more the wheel will stick out.

 

Take a look here:
Visual Backspace Explaination - Simple Drawings of 3 wheels w/ different backspacing

I did it for myself, to grasp the concept, and it seems to have helped others.
It won't apply to your specific install, but it should start you in the right direction

Also look thru the "Stickies" in the beginning of the "Wheels & Tires" Forum"

Take note that an 8" Wheel (for example) does not include the lip and actually measures 9",
if you lay it's back (mounting surface side) flat on the floor and measure to the "top" (front) of the wheel.
The backspacing measurement makes use of the extreme outer measurement of the width, in this case 9",
whereas the Offset is measured from the centerline of the wheel and the width is not relevant.
So Offset is how far in mm (+ or -) the mounting surface is from the Centerline of the wheel, and is not width related.
And the Backspace is how far in inches the mounting surface is from the back edge of the wheel. and is width related.
Both measurements are required with your Tire size and profile to determine how far your tires will "stick out"
And if they will come in contact with components behind the wheel such as the Upper Control Arm.

Do some research before deciding, if you don't want to do it twice.

Good Luck
CC

 

It has nothing to do with how far it will stick out, at least as a pure number.
The wheel manufacturer has no clue what vehicle you are installing it on. You need to compare against stock, or a known measurement.

Example:
If you have a 16x7 with zero offset stock wheel, and you replace it with a 16x8 with zero offset, then the new tire will BOTH stick out and in by 1/2" more than stock.
Looking at backspacing, if you have a 16x7 with 4.5" backspacing stock wheel, and you replace it with a 16x8 with 4.5" backspacing, then the new tire will stick out by 1" more than stock.

Keep in mind that for calculating offset and backspacing, add 1" to the rim width. A 16x8 is actually 9" wide, so zero offset is 4.5" backspacing.
How that differs from your stock rim depends on the backspacing of the stock rim.

 

Thoughts on 16x8" 4" backspace on a 265/75 AT on a second gen with 3" of lift?

 

Should have no clearance problems...

 

I need help with rims. I purchased pro comp 15X7 with 3.5 backspacing. They did not fit because of the rub on the front brake.. What do i need to fix it or is there a rim that can fit?

 

Check out some of the Links in this thread....

http://www.tacomaworld.com/forum/wheels-tires/98786-backspacing-offset.html

 

16" rim.

2nd Gen gets touchy as well. The 5-lug comes with 15" and 6 lug gets 16", but many aftermarket rims in those sizes will rub the caliper.

A spacer MAY help, but if you're already at 3.5" BS, you're already shallower than recommended.