Backspacing and Offset to Run 35”

lalalofsky

Well-Known Member
First Name
Ben
Joined
Sep 27, 2020
Messages
271
Reaction score
49
Location
Lawrence, Kansas
Vehicle(s)
2020 JLU Sport
What backspacing and offset do I need to run 35s without rubbing on my JLU. I have rubicon fenders and a rubicon lift. Im not really worried about bumping, but rubbing at or almost full lock is a concern. I am horrible at understanding offset and backspacing so I’m looking for knowledge.

thank you





Advertisement

 

Some Random Guy

Well-Known Member
Joined
Sep 16, 2020
Messages
235
Reaction score
339
Location
Washington
Vehicle(s)
2020 JLUR, 2018 Subaru BRZ
Occupation
Comptroller
It depends on your lift kit. I think the rubicon lift/tire combo will rub when offroad with 35’s. They say you need the mopar lift to run 35’s without rubbing. I don’t think backspacing is an issue with the stock wheels unless you step out to aftermarket lifts.
 
OP
lalalofsky

lalalofsky

Well-Known Member
First Name
Ben
Joined
Sep 27, 2020
Messages
271
Reaction score
49
Location
Lawrence, Kansas
Vehicle(s)
2020 JLU Sport
  • Thread starter
  • Thread Starter
  • #3
It depends on your lift kit. I think the rubicon lift/tire combo will rub when offroad with 35’s. They say you need the mopar lift to run 35’s without rubbing. I don’t think backspacing is an issue with the stock wheels unless you step out to aftermarket lifts.
I am close to 2” in lift, i thought I needed aftermarket wheels, or wheel spacers because my axles aren’t as wide as the rubicons.
 

Some Random Guy

Well-Known Member
Joined
Sep 16, 2020
Messages
235
Reaction score
339
Location
Washington
Vehicle(s)
2020 JLUR, 2018 Subaru BRZ
Occupation
Comptroller
The Rubicon suspension alone can’t handle 35’s offroad. My understanding is the mopar lift builds further on the Rubicon height. It would be fine on-road, though.
I forgot about the Rubicon having wider axles. Someone else may have to answer that. If you need spacers, aftermarket wheels can accomplish the same thing with reduced backspacing and potentially give you beadlocks.
 

Arterius2

Well-Known Member
First Name
Jerry
Joined
Dec 29, 2018
Messages
3,482
Reaction score
4,420
Location
Vancouver, BC
Vehicle(s)
2018 JLU Sahara 2.0L
I am close to 2” in lift, i thought I needed aftermarket wheels, or wheel spacers because my axles aren’t as wide as the rubicons.
35” is the diameter of the tire, not the width. And I don’t think anyone is forcing you to mount 12.5” width tires. Plenty of 35x11 or 35x11.5 or even 35x10 tires to choose from.

Here is my Sahara on 35x11.2 on stock wheel, no wheel spacers. No rubbing.

8AAA3147-5F7E-4C79-803C-F8A9C78653C1.jpeg
 
Last edited:

Arterius2

Well-Known Member
First Name
Jerry
Joined
Dec 29, 2018
Messages
3,482
Reaction score
4,420
Location
Vancouver, BC
Vehicle(s)
2018 JLU Sahara 2.0L
The Rubicon suspension alone can’t handle 35’s offroad. My understanding is the mopar lift builds further on the Rubicon height. It would be fine on-road, though.
I forgot about the Rubicon having wider axles. Someone else may have to answer that. If you need spacers, aftermarket wheels can accomplish the same thing with reduced backspacing and potentially give you beadlocks.
This is wrong.
 
OP
lalalofsky

lalalofsky

Well-Known Member
First Name
Ben
Joined
Sep 27, 2020
Messages
271
Reaction score
49
Location
Lawrence, Kansas
Vehicle(s)
2020 JLU Sport
  • Thread starter
  • Thread Starter
  • #7
35” is the diameter of the tire, not the width. And I don’t think anyone is forcing you to mount 12.5” width tires. Plenty of 35x11 or 35x11.5 or even 35x10 tires to choose from.

Here is my Sahara on 35s and stock wheel, no wheel spacers. No rubbing.

8AAA3147-5F7E-4C79-803C-F8A9C78653C1.jpeg
I know that 35” is the diameter. I forgot to add the width aspect. My bad. I was looking at 12.5s but I suppose 11.5 is fine too. what is your width? Nice looking jeep. I appreciate the photo!
 

Arterius2

Well-Known Member
First Name
Jerry
Joined
Dec 29, 2018
Messages
3,482
Reaction score
4,420
Location
Vancouver, BC
Vehicle(s)
2018 JLU Sahara 2.0L
I know that 35” is the diameter. I forgot to add the width aspect. My bad. I was looking at 12.5s but I suppose 11.5 is fine too. what is your width? Nice looking jeep. I appreciate the photo!
Measures 35.1x11.2 (285/75R18)

there are a few 35x11.5R17 from the likes of Nitto and Toyo to choose from.

I know you got to kind of poke around and find the specific tires for your needs and may be more of a work, but in the end it’s well worth it.
 
OP
lalalofsky

lalalofsky

Well-Known Member
First Name
Ben
Joined
Sep 27, 2020
Messages
271
Reaction score
49
Location
Lawrence, Kansas
Vehicle(s)
2020 JLU Sport
  • Thread starter
  • Thread Starter
  • #9
Measures 35.1x11.2 (285/75R18)

there are a few 35x11.5R17 from the likes of Nitto and Toyo to choose from.
Do you know what offset and backspacing is needed to run 35x12.5x17(18)? I am looking at wheels and tires. I am doubting my ability to appropriately choose the right size. I really like the look of 12.5, but i might go with the 11.5 if i cant find a wheel I really Like At the moment.

I really like your set up, what wheels are you running? They look sharp. Also how do you like those PIAA?
 

Arterius2

Well-Known Member
First Name
Jerry
Joined
Dec 29, 2018
Messages
3,482
Reaction score
4,420
Location
Vancouver, BC
Vehicle(s)
2018 JLU Sahara 2.0L
Do you know what offset and backspacing is needed to run 35x12.5x17(18)? I am looking at wheels and tires. I am doubting my ability to appropriately choose the right size. I really like the look of 12.5, but i might go with the 11.5 if i cant find a wheel I really Like At the moment.

I really like your set up, what wheels are you running? They look sharp. Also how do you like those PIAA?
Wheel factory offset on these stock wheels are 44mm. And Rubicon axles are 0.75 wider than Sport/Sahara on each side. Which is 19mm.
So if my math is correct 44-19=25mm offset would get you the same stance as a Stock Rubicon axle.
 
OP
lalalofsky

lalalofsky

Well-Known Member
First Name
Ben
Joined
Sep 27, 2020
Messages
271
Reaction score
49
Location
Lawrence, Kansas
Vehicle(s)
2020 JLU Sport
  • Thread starter
  • Thread Starter
  • #11
Measures 35.1x11.2 (285/75R18)

there are a few 35x11.5R17 from the likes of Nitto and Toyo to choose from.

I know you got to kind of poke around and find the specific tires for your needs and may be more of a work, but in the end it’s well worth it.
What is the though on the 15inch wheel? Lol is that too small?
 
OP
lalalofsky

lalalofsky

Well-Known Member
First Name
Ben
Joined
Sep 27, 2020
Messages
271
Reaction score
49
Location
Lawrence, Kansas
Vehicle(s)
2020 JLU Sport
  • Thread starter
  • Thread Starter
  • #12
Wheel factory offset on these stock wheels are 44mm. And Rubicon axles are 0.75 wider than Sport/Sahara on each side. Which is 19mm.
So if my math is correct 44-19=25mm offset would get you the same stance as a Stock Rubicon axle.
I believe that looks correct to me. Thank you for getting me those numbers.
 

Arterius2

Well-Known Member
First Name
Jerry
Joined
Dec 29, 2018
Messages
3,482
Reaction score
4,420
Location
Vancouver, BC
Vehicle(s)
2018 JLU Sahara 2.0L
I really like your set up, what wheels are you running? They look sharp. Also how do you like those PIAA?
I’m running stock Sahara wheels.
PIAA is decent, light output isn’t great, but cut-off is really good. it works with my fogs to give some low angle illumination in bad weather.
 

Some Random Guy

Well-Known Member
Joined
Sep 16, 2020
Messages
235
Reaction score
339
Location
Washington
Vehicle(s)
2020 JLUR, 2018 Subaru BRZ
Occupation
Comptroller
This is wrong.
Which part? The stock rubicon suspension doesn’t do 35’s offroad without rubbing. Link. I don’t know much about the mopar lift, so I’m not sure if that’s what you mean.
As for axle width, reducing backspacing will push the wheels out so they don’t contact the suspension at flex. The other posts show the offset calculations. Same effect as spacers since OP has narrower axles.
 

Advertisement




Icon Vehicle Dynamics
 



Advertisement
Top