SFBayArea

Does everyone quote backspacing for the stock vehichle? What about those that are lifted? I am considering lifting my jeep with 2.5" TF BB and with such I read I need to get wheels with 4.5 back spacing.

captjay

in a short easy explanation, the higher the number ie. 6" bs, the closer the wheel and tire are to components. the lower the number 3.75" bs, the further away the tire and wheel are from components. when you install a lift and change the wheels and tires, you have to pay attention to backspacing so your tire will not interfere or rub on anything.

4.5" of backspacing will usually put your tire and wheel far enough away from everything that you should not rub. usually you can run a rim with 4.5" and a 12.50" wide tire and be ok, but for example, my tire is 13.50" wide so 4.5" bs does not work for me. I have 3" bs to put my tire far enough away that I do not rub

hope that helped.

edit: below says 6" on factory wheels, I believe it is actually 6.25"
Wheels

JK wheels are 5 on 5 bolt spacing

backspacing - distance from the rear of the wheel to the mounting surface (inches)
offset - distance from the center of the wheel to the moounting surface (+/-mm)

15" wheel
some 15 wheels will fit depending on the manufacturer.
3.75 to 4.25 backspacing will be required depending on style and width of rim.

16" wheel
factory 16" wheels are 7" wide with 5.5" backspacing. (standard and optional X)
most/all aftermarket 16" wheels will fit reguardless of backspacing.
up to an 11.5" wide tire can be placed on the factory wheels but 1-1.5" wheel spacer will be needed

17" wheel
factory 17" wheels are 7.5" wide with 6" backspacing. (optional X, Sahara and Rubicon)
Optional X and Sahara 17" wheels are painted silver, Rubicon have a machined face
most/all aftermarket 17" wheels will fit reguardless of backspacing.
up to an 12.5" wide tire can be placed on the factory wheels but 1-1.5" wheel spacer will be needed

18" wheel
factory 18" wheels are 7.5" wide with 6" backspacing. (optional Sahara)
up to an 12.5" wide tire can be placed on the factory wheels but 1-1.5" wheel spacer will be needed_

captjay

here is the longer, more complicated mathematical explanation

but it has pictures!!

http://project-jk.com/jeep-jk-tech/t...do-they-relate

JDScott10

Funniest thing I've read all day...the other group not running stock or aftermarket are the ones with their rigs on blocks waiting for the option of tank treads

07 JK "bullfrog"

Thank you for answering some questions I had in mind. I have a jk X model with 4"teraflex and 37's, and 18" rims. I don't like the rims that ate on there( bought jeep with them on there already) and was wanting to get some black steel rims. This is my daily driver. My question is, what size should I get? I wheel often as possible.

SFBayArea

Thank you captjay. It looks like to be safe and make sure my wheel or tire does not rub after the lift kit installed I will probably need to look for 15" wheels with 3.75 or 4" BS.

captjay

no problem man, that's what the forum is here for, to help each other out. ask questions and do your research and your Jeep will turn out great

captjay

actually that's good you point that out, I'm not saying the bs has to be exactly 3.75, typically, as long as it is 4" or lower, then should be a good fit. but 3.75" and under seems to be the going number.

Harbourone

I've seen the root cause on 3 sets of cragar soft 8's Jay. It wasn't the bs issue, it was the stamping. The bs would have just moved the outer rim of the wheel on the face.


The only reason a spacer makes a difference is that it puts some distance between the stamping edges and the caliper. And that's the key. Jeep has terrible tolerance allowances.


Cragar makes uniform product stamped for the same type of steel in the same temperature at the same psi day in day out. Our calipers have nearly a 1/4 inch deviation from one extreme to the other.


That's why the fit is so temperamental on most 15's.


Try a set of Stockton smoothies in any custom bs build you want. I'd bet they fit perfectly as there are no cutouts stamped in the wheel.,

SFBayArea

I am actually too thinking of going with aluminum wheels to save some weight. Which wheels do you run on your rig and where did you get them?