Wheel Offset and Backspace | How do they relate?

[Evolkidbell]

Look up the bolt pattern for 97-03 f150, or the 97-98 f250 7700.... Ford has a history of being difficult lol.

Yeah, the great 7-lug F-150s.
I knew some Stock Full racers that preferred that rear end as the diff was HD and you could re-drill the axle flanges to what you need. Still considered "Stock" to meet class rules. Was like a Superduty Diff in a F-150.

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[Discount Tire]

Thanks to Discount Tire! First of all let me say that I know very little about tires.

But I was running tire numbers this morning. Previous posts here say that Badlands optional wheel has 55mm offset. I assume standard wheel is the same. Maybe. If so, backspace is 6.66". Distance from mounting plate to outside of wheel would be 2.34"

I was looking at Fuel Wheel Vector, 8.5" with a 7mm offset, making backspacing 5.02". Distance from mounting plate to outside of wheel would be 4.48".

So inside of Fuel wheel would be 1.64" closer to the mounting plate compared to the Badlands wheel. So 1.64" of extra clearance laterally. This in my mind says that rubbing should not be a problem.

But the Fuel wheel would stick out 2.15" farther on each side. Is there a downside to the wheels sticking out 2.15" farther? Or any other downside that I don't know of?

Always happy to help! Your numbers are spot on

As for the aftermarket wheels sitting further out, there's pros and cons. The increase will change the handling characteristics of the vehicle, which some may actually prefer, and the argument can be made that additional stress is added to the suspension components. It really boils down to the tire size/wheel combo and what you're looking to do with the vehicle.

 

[mbagne]

Folks in this thread are way more knowledgeable than I . . . here's a question if anyone has an answer:

I have a set of Mickey Thompson 35” Baja AT-Z’s waiting for my Bronco when it arrives and would like to go ahead and match with aftermarket wheels. For a Badlands/4-door Sasquatch would one of the following wheels work? If not, what would I need to do to make one of them work?

Method 17” wheel, 8.5” wide with 0 offset and backside spacing of 4.75”.

Method 17” wheel, 9” wide with a -12 offset and backside spacing of 4.5”.

 

[Discount Tire]

Folks in this thread are way more knowledgeable than I . . . here's a question if anyone has an answer:

I have a set of Mickey Thompson 35” Baja AT-Z’s waiting for my Bronco when it arrives and would like to go ahead and match with aftermarket wheels. For a Badlands/4-door Sasquatch would one of the following wheels work? If not, what would I need to do to make one of them work?

Method 17” wheel, 8.5” wide with 0 offset and backside spacing of 4.75”.

Method 17” wheel, 9” wide with a -12 offset and backside spacing of 4.5”.

Great question and from my understanding the SAS has more room in the fender well. Looking at recently released fitment details on the Badlands, it appears both wheel options would actually fit with 35's under normal street driving.

Depending on how you plan to use your rig, you may want to lean towards the the 17x8.5 with 0 offset as it will keep the tire/wheel assembly deeper within the wheel well when compared to the 17x9 with -12mm offset. This would help limit the amount of potential rubbing points when articulating the suspension off-road.

Full disclosure, we haven't measured any of the 6G Broncos as of yet, therefor can not guarantee the fitment.

 

[pakrat]

So anybody who has taken delivery of a production Bronco able to give a definitive answer on factory offset for the standard 17" wheels and the squatch 17" beadlock capable wheels? I'm seeing +55 for the standard is that confirmed? And the Sasquatch?

 

[L8apex]

Hello Discount Tire - much thanks info -

Small correction to the math in Example for 9" wide wheel -
. . . Zero Offset ==> Backspace = 4.5"
. . . +12mm Offset ==> Backspace = 5.0"
. . . -12mm Offset ==> Backspace = 4.0"


Note: the Offsets & Backspaces given in the Example would apply to a 10" wide wheel -
Probably what you meant to say -

You missed step 1.

First - add 1" to the rim width and then divide by 2 to find the wheels center line (you have to account for the wheel flange which is why you add 1" to the rim width) .

 

[NewBroncoOwner]

www.trailbuilt.com is a sister company of custom offsets. I snagged a set of KMC Holeshots 17x8.5 (6x5.5" bolt pattern) and wrapped it in 265 65 17 KO2s to keep the original rolling diameter. I am at work now but i can provide pics later. the stock offset on a base is +55, i got a +34 just to make sure i clear any components when turning. Stay close as you can to the stock offset to prevent un wanted wear on other components.

 

[L8apex]

Thanks - yes then it's 10" wide - what I thought they meant to say -

The diagrams look different - don't see the extra 1" in diagram ?

A wheel labeled as a 9" wheel is 10" wide. Where the tire sits is 9".


A quick example of a 8.5" wheel:

 

[L8apex]

Yes this diagram is good - shows the extra width caused by the two flanges -
The flanges are always 0.5 inch wide ?

~0.5" is close enough for most wheels. If your BS calcs come close enough to hitting other components with using 0.5" then you should be looking at a different wheel

 

[Discount Tire]

@L8apex is correct, the labeled wheel width is the measurement, in inches, from bead seat to bead seat across the barrel of the wheel. In most instances the rim flange is 1/2-inch.

 

[kkurni]

I have Outer bank sasquatch package. But still want to upgrade to 20".
What is the most negative offset that I can have without rubbing the OEM sasquatch fender / OEM lift kit?

Will -12 or-24 negative offset possible?

Does discount tire wheel selection making sure that there will be no rubbing when up sizing to 20" wheel?

 

[Discount Tire]

I have Outer bank sasquatch package. But still want to upgrade to 20".
What is the most negative offset that I can have without rubbing the OEM sasquatch fender / OEM lift kit?

Will -12 or-24 negative offset possible?

Does discount tire wheel selection making sure that there will be no rubbing when up sizing to 20" wheel?

Thank you for reaching out @kkurni

Rim width, offset, suspension, as well as the tire size, all play a roll in the overall fit. For example, a 20x9 with -12mm offset shod with 35x12.50R-20 tires will fit different than a 20x10 with -12mm offset shod with 35x12.50R-20 tires. Think of your wheel wells as bowl shaped, if you push them out too far (with low offset) you are locating the wheel in a shallower part of your wheel well which may require modifications (such as removing the crush bars) depending on the intended tire size.

Generally speaking, the wheel models listed when searching by vehicle on our website fit factory tire sizes +1 inch.

We're happy to help dial in the fitment with you, PM coming your way.

 

[Inlinejohn]

Thank you for reaching out @kkurni

Rim width, offset, suspension, as well as the tire size, all play a roll in the overall fit. For example, a 20x9 with -12mm offset shod with 35x12.50R-20 tires will fit different than a 20x10 with -12mm offset shod with 35x12.50R-20 tires. Think of your wheel wells as bowl shaped, if you push them out too far (with low offset) you are locating the wheel in a shallower part of your wheel well which may require modifications (such as removing the crush bars) depending on the intended tire size.

Generally speaking, the wheel models listed when searching by vehicle on our website fit factory tire sizes +1 inch.

We're happy to help dial in the fitment with you, PM coming your way.

Can you help me understand how well a Black Rhino Abram with -18offset and BFG 315/70-17 KM3 will fit a Badlands Sasquatch with 2.25” lift/level? Going from factory +55 to -18 seems a big jump.

 

[Discount Tire]

Can you help me understand how well a Black Rhino Abram with -18offset and BFG 315/70-17 KM3 will fit a Badlands Sasquatch with 2.25” lift/level? Going from factory +55 to -18 seems a big jump.

Absolutely, happy to help!

SAS wheels are 8.5-inches wide with +30mm offset and the 17-inch Abrams in 6-139.7 is 8.5-inches wide with -18mm offset (also available with 0 offset).

The 17x8.5 -18 is going to sit 2-inches outwards towards the fender when compared to where the factory wheel sits now. If you take a tape measure and measure from the front lip of the factory wheel outwards 2-inches, this will be the point where the front lip of the 17x8.5 -18 is going to sit. Here's a visual, orange is stock and blue is the 17x8.5 +18

For good measure, the 17x8.5 0 offset is going to sit just under 1-1/4 inches further out when compared to stock.

Either option is going to work for you , however if you plan on wheeling your rig you may want to lean towards the 0 offset. When the suspension is flex/compressed, the -18 offset may rub.

 

[North7]

Absolutely, happy to help!

SAS wheels are 8.5-inches wide with +30mm offset and the 17-inch Abrams in 6-139.7 is 8.5-inches wide with -18mm offset (also available with 0 offset).

The 17x8.5 -18 is going to sit 2-inches outwards towards the fender when compared to where the factory wheel sits now. If you take a tape measure and measure from the front lip of the factory wheel outwards 2-inches, this will be the point where the front lip of the 17x8.5 -18 is going to sit. Here's a visual, orange is stock and blue is the 17x8.5 +18

For good measure, the 17x8.5 0 offset is going to sit just under 1-1/4 inches further out when compared to stock.

Either option is going to work for you , however if you plan on wheeling your rig you may want to lean towards the 0 offset. When the suspension is flex/compressed, the -18 offset may rub.

What detrimental effects will that have on drive train component wear and scrub radius?

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