School me on wheel offset.

[Stockweiser]

Just bought a 22 Gladiator Rubicon and will be putting a 2.5" lift with 37x13.5 Ridge Grapplers on it. I trying to calculate what offset is needed if needed at all. Does anyone have a explanation or equation?

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[Rahkmalla]

Offset is how many millimeters from dead center of the wheel the mounting face is. 0 is dead center. Positive moves towards the exterior of the wheel (moving the tire inward) and negative moves towards the interior of the wheel (moving the tire outward)

25.4mm=1 inch.

The general rule for flush fit 12.5s on wide axles is +25. Flush fit 13.5s would require +37, but that would rub on the interior so you can't flush fit 13.5s on a gladiator. I'd try to stick with +12 wheels. Any more negative offset with 13.5 width and things get real pokey real quick.

Some (like me) prefer offset to backspace because it kind of ignores wheel width, since a wheel and tire share their center line. +25 on 8 inch wheels fits the tire relative to the body the exact same way as +25 on 9 inch wheels.

 

[Stockweiser]

Offset is how many millimeters from dead center of the wheel the mounting face is. 0 is dead center. Positive moves towards the exterior of the wheel (moving the tire inward) and negative moves towards the interior of the wheel (moving the tire outward)

25.4mm=1 inch.

The general rule for flush fit 12.5s on wide axles is +25. Flush fit 13.5s would require +37, but that would rub on the interior so you can't flush fit 13.5s on a gladiator. I'd try to stick with +12 wheels. Any more negative offset with 13.5 width and things get real pokey real quick.

Some (like me) prefer offset to backspace because it kind of ignores wheel width, since a wheel and tire share their center line. +25 on 8 inch wheels fits the tire relative to the body the exact same way as +25 on 9 inch wheels.

Thank you for the explanation. I was quoted a -12 from a dealership on 17x9 KMC wheels.

 

[Lunentucker]

Stock Rubicon is +44 mm offset at 7.5" wide.
For every inch of rim width you add, you would need to compensate by reducing positive offset by 1/2" (13 mm) to stay even.

https://tiresize.com/wheel-offset-calculator/

 

[Lunentucker]

Thank you for the explanation. I was quoted a -12 from a dealership on 17x9 KMC wheels.

+44 - 19 (3/4") = +25
-12 is way more than needed.

Most aftermarket rims are made to fit a wide variety of stock vehicles without spacers, so 0 to -25 offsets are popular and common. Jeep is not most stock vehicles, and that's why stock is +44.

 

[Stockweiser]

+44 - 19 (3/4") = +25
-12 is way more than needed.

Most aftermarket rims are made to fit a wide variety of stock vehicles without spacers, so 0 to -25 offsets are popular and common. Jeep is not most stock vehicles, and that's why stock is +44.

Thank you.

 

[kevman65]

If you've decided on a lift kit, ask the manufacturer of that lift what their recommended wheel back space is.
Saves you the headache of trying to figure what you need, they've already done the math and then proven it with practical application.

 

[Escape.idiocracy]

https://www.jeepgladiatorforum.com/forum/threads/method-wheels-showoff-your-setup.63462/

Lots of good info in your thread.
I’m a visual person- I like the math/calculator to generalize but resort to photos…. It’s nice to see different lift dynamics at play.

something to consider- sometimes what “looks” good on flat ground does not flex well or- maybe better worded, requires additional bump stoping to work.

 

[gatorboy]

+44 - 19 (3/4") = +25
-12 is way more than needed.

Most aftermarket rims are made to fit a wide variety of stock vehicles without spacers, so 0 to -25 offsets are popular and common. Jeep is not most stock vehicles, and that's why stock is +44.

If I have stock wheels on a 2022 Mojave and I put -18 on a 9.5x17 arsenals, how much will it stick out past the fenders. Hope not too much.

 

[gatorboy]

If I have stock wheels on a 2022 Mojave and I put -18 on a 9.5x17 arsenals, how much will it stick out past the fenders. Hope not too much.

I’m putting 35” Baja Boss Mickey’s on em.

 

[Lunentucker]

If I have stock wheels on a 2022 Mojave and I put -18 on a 9.5x17 arsenals, how much will it stick out past the fenders. Hope not too much.

https://tiresize.com/wheel-offset-calculator/

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