Quick wheel advice....

[Overwatch]

I am posistive this has been covered a hundred times before and I'm just being lazy. However I'm adding 35 inch (12.5) tires to my Jeep and want a new Black Rhino wheel. Anyone know the offset/backspacing I need?

Sponsored

 

[DavidArmen]

It’s not really about what you need but rather what you want. In terms of backspacing, which is usually in inches, the smaller the number, the more the wheel will stick out. In terms of offset, which is usually measured in millimeters, the smaller the number the more the wheel will stick out.

The stock rubicon wheels are 7.5” wide and, according to these forums, have a ~6.125” backspace and a ~45mm offset. If you want your wheels to stick out more than the stock rubicon wheels, you want those two numbers to be smaller.

For example, my rubicon has icon dynamics wheels that are 8.5” wide with the following specs: 4.5” backspacing and -6mm offset.

Which basically means that my wheels stick out a little over 2.5” compared to stock:

45mm - (-6mm) = 51mm = 2.008” = ~2”

My wheels are 1” wider so that is 0.5” on each side:

2” + 0.5” = 2.5”

Side note: my 8.5” wheels have 12.4” (315mm) tires mounted on them.

 

[stumblinhorse]

Great post by @DavidArmen. Last thing to add, is beyond personal preference, as you get wider tires, they have only 2 places to go. further into the wheel well or outside the fender. If you don’t increase the amount of tire showing outside the fender by lowering backspace, the tire moves closer to the inner fender. That means rubbing! So most will decrease BS by roughly the amount of width of tire you added from stock.

 

[jeepoch]

Dave,

Here's what 35x12.5x17's look like with a -12mm offset.

 

[GATORB8]

It’s not really about what you need but rather what you want. In terms of backspacing, which is usually in inches, the smaller the number, the more the wheel will stick out. In terms of offset, which is usually measured in millimeters, the smaller the number the more the wheel will stick out.

The stock rubicon wheels are 7.5” wide and, according to these forums, have a ~6.125” backspace and a ~45mm offset. If you want your wheels to stick out more than the stock rubicon wheels, you want those two numbers to be smaller.

For example, my rubicon has icon dynamics wheels that are 8.5” wide with the following specs: 4.5” backspacing and -6mm offset.

Which basically means that my wheels stick out a little over 2.5” compared to stock:

45mm - (-6mm) = 51mm = 2.008” = ~2”

My wheels are 1” wider so that is 0.5” on each side:

2” + 0.5” = 2.5”

Side note: my 8.5” wheels have 12.4” (315mm) tires mounted on them.

Great post, note the wheel width matters less than the tire section width, so I'd recommend using that instead.

To add a little. If you plan to lift in the future, a maximum backspacing of 4.5" will keep your options open. Greater than that, front LCA clearance impacts which lifts you can use.

 

[Overwatch]

Thank you for this. I have no idea why but I am really having trouble wrapping my head around the numbers on the website. The 392 wheels have a 6 inch backspace. So if I get ones that are 4.5 they will stick out 1.5 inches. Where I'm getting lost is offset. Is that just the same thing said a different way, is it the difference between the two, or is it something else?

 

[stumblinhorse]

Thank you for this. I have no idea why but I am really having trouble wrapping my head around the numbers on the website. The 392 wheels have a 6 inch backspace. So if I get ones that are 4.5 they will stick out 1.5 inches. Where I'm getting lost is offset. Is that just the same thing said a different way, is it the difference between the two, or is it something else?

Explained; https://www.motortrend.com/how-to/0706tr-wheel-backspace-and-offset/

 

[Overwatch]

It’s not really about what you need but rather what you want. In terms of backspacing, which is usually in inches, the smaller the number, the more the wheel will stick out. In terms of offset, which is usually measured in millimeters, the smaller the number the more the wheel will stick out.

The stock rubicon wheels are 7.5” wide and, according to these forums, have a ~6.125” backspace and a ~45mm offset. If you want your wheels to stick out more than the stock rubicon wheels, you want those two numbers to be smaller.

For example, my rubicon has icon dynamics wheels that are 8.5” wide with the following specs: 4.5” backspacing and -6mm offset.

Which basically means that my wheels stick out a little over 2.5” compared to stock:

45mm - (-6mm) = 51mm = 2.008” = ~2”

My wheels are 1” wider so that is 0.5” on each side:

2” + 0.5” = 2.5”

Side note: my 8.5” wheels have 12.4” (315mm) tires mounted on them.

Thank yuo for taking the time to put this all in here, it truly helped.

 

[GATORB8]

Thank you for this. I have no idea why but I am really having trouble wrapping my head around the numbers on the website. The 392 wheels have a 6 inch backspace. So if I get ones that are 4.5 they will stick out 1.5 inches. Where I'm getting lost is offset. Is that just the same thing said a different way, is it the difference between the two, or is it something else?

Backspace is impacted by wheel width, offset isn't so it isn't that clear cut.

Just plug and chug here:
https://tiresize.com/wheel-offset-calculator/

 

[JL MADDOG]

Backspace is impacted by wheel width, offset isn't so it isn't that clear cut.

Just plug and chug here:
https://tiresize.com/wheel-offset-calculator/

I've used the same calculator numerous times for wheel & tire fitment on my vehicles.

When you go as low as I did with my 300C SRT8 with coilovers and bigger swaybars you need to be pretty accurate or bad things will happen.

 

[m5guy]

Here's our JLUR392 with 37" KO2s (12.5) - 17x9 inch wheels with a +18 offset. I prefer the tire to be tucked in closer to the vehicle personally and this combo works well for us. 2.5 inches of additional lift on it as well.

 

[Overwatch]

Here's our JLUR392 with 37" KO2s (12.5) - 17x9 inch wheels with a +18 offset. I prefer the tire to be tucked in closer to the vehicle personally and this combo works well for us. 2.5 inches of additional lift on it as well.

That's exactly what I've been looking at, what's your backspacing on the wheels?

 

[GATORB8]

That's exactly what I've been looking at, what's your backspacing on the wheels?

+18 on a 9 is 5.7 in BS.

We have the same offset on ours, but 8.5", which makes ours 5.5 in BS.

 

[Overwatch]

+18 on a 9 is 5.7 in BS.

We have the same offset on ours, but 8.5", which makes ours 5.5 in BS.

Thank you!!!!!

 

[The Last Cowboy]

A 9” wheel with +18 to +12 will get you that flush look. Almost every single 18” tire out there will be load range E and heavy. Shop carefully for the right tire. 17” gives you more options.

Sponsored