1/4” wheel spacer on Mojave.

[Planerdude]

Why is this always so hard for people to wrap their heads around?

Same offset + different width = different backspacing
Same backspacing + different widths = different offset

This is why backspacing is SOOOOOO much easier to deal with when you are working on a Jeep. A 15" wide wheel with 3" of backspacing is going to be the exact same distance from your suspension components/frame as a 4" wide wheel with 3" of backspacing. If you've got a bigger tire with more bulge in the sidewall then get something with LESS backspacing.

GENERALLY SPEAKING... the inside of the wheel is the important part on a Jeep. Sure, if your setup is too wide with too little backspacing, and you actually wheel your Jeep, then you can have issues getting into your fenders when you are flexed out.

Keep it simple. Life's easier that way. I feel like the debate about how to make these measurements comes up way too often and it's always someone trying to flex their muscles about how smart they are since they can do simple math. Doing it all based off of offset calculations is like a young engineer that's never gotten his hands dirty but wants to prove his concept with math vs the backspacing route being an old callus-handed farmer just knowing what works. HAHA!

All this, and my Only question was, will my wheel studs need to be replaced when adding a 1/4” thick spacer?

Sponsored

 

[JT1]

All this, and my Only question was, will my wheel studs need to be replaced when adding a 1/4” thick spacer?

Will it fit? yes. Would I run it? No chance. Buy a wheel that fits. 35x12.5's and 37x12.5s have been used on stock Rubicons. The 37 WILL rub on the LCA, on a +45 offset 7.5" wheel.

 

[Planerdude]

Will it fit? yes. Would I run it? No chance. Buy a wheel that fits. 35x12.5's and 37x12.5s have been used on stock Rubicons. The 37 WILL rub on the LCA, on a +45 offset 7.5" wheel.

So i am keeping my new wheel at a +37mm offset, factory specs, with the 12.5 bfg tire i am running now. No rubbing. Add 1 or 2 inches of rim width, (agree changes backspacing) does in no way put the tire any closer to the shocks or lca. What am I missing here. See attached pic and tell me where i am wrong.

 

[JT1]

So i am keeping my new wheel at a +37mm offset, factory specs, with the 12.5 bfg tire i am running now. No rubbing. Add 1 or 2 inches of rim width, (agree changes backspacing) does in no way put the tire any closer to the shocks or lca. What am I missing here. See attached pic and tell me where i am wrong.

Turn your wheel Full Driver, then get out and see how close the inside of the tire is to your lower control arm at the rear of the front wheelwell. On a 35" tire it will fit, on a 37 it will rub.

 

[Renegade]

Why is this always so hard for people to wrap their heads around?

Same offset + different width = different backspacing
Same backspacing + different widths = different offset

This is why backspacing is SOOOOOO much easier to deal with when you are working on a Jeep. A 15" wide wheel with 3" of backspacing is going to be the exact same distance from your suspension components/frame as a 4" wide wheel with 3" of backspacing. If you've got a bigger tire with more bulge in the sidewall then get something with LESS backspacing.

GENERALLY SPEAKING... the inside of the wheel is the important part on a Jeep. Sure, if your setup is too wide with too little backspacing, and you actually wheel your Jeep, then you can have issues getting into your fenders when you are flexed out.

Keep it simple. Life's easier that way. I feel like the debate about how to make these measurements comes up way too often and it's always someone trying to flex their muscles about how smart they are since they can do simple math. Doing it all based off of offset calculations is like a young engineer that's never gotten his hands dirty but wants to prove his concept with math vs the backspacing route being an old callus-handed farmer just knowing what works. HAHA!

We disagree.

 

[Planerdude]

Turn your wheel Full Driver, then get out and see how close the inside of the tire is to your lower control arm at the rear of the front wheelwell. On a 35" tire it will fit, on a 37 it will rub.

Except I’m not running a 37, im running a 12.5 x35.

 

[JT1]

Except I’m not running a 37, im running a 12.5 x35.

If you are on stock wheels now, see how close you are to rubbing the LCA. If its closer than half an inch, you will rub. 35s will clear on stock mojave wheels. a +37 on an 8.5" wheel is a half inch more inboard.

 

[Planerdude]

If you are on stock wheels now, see how close you are to rubbing the LCA. If its closer than half an inch, you will rub. 35s will clear on stock mojave wheels. a +37 on an 8.5" wheel is a half inch more inboard.

This is at full lock. 2+ inches

 

[JT1]

This is at full lock. 2+ inches

That clearance looks good. Pics are always a little deceiving. How close is that lower shock mount to you inner wheel?

 

[Planerdude]

That clearance looks good. Pics are always a little deceiving. How close is that lower shock mount to you inner wheel?

To the tire 1 3/4” to the wheel another 3/4 +
This is at full lock, strap the steering to the rock rail?, stock 7.5 wide mojave wheels, with 35x12.5x17 BFGs

 

[JT1]

To the tire 1 3/4” to the wheel another 3/4 +
This is at full lock, strap the steering to the rock rail?, stock 7.5 wide mojave wheels, with 35x12.5x17 BFGs

I'd say you're safe then, no spacer needed on the 8.5" wheel you're looking at.

 

[Planerdude]

Patience grasshopper...

Out of the 3 pages of non-answers to my questions, your response is the winner, i am going to wait for the 8.5x18x34mm offset to become available. Thanks

 

[Planerdude]

Why is this always so hard for people to wrap their heads around?

Same offset + different width = different backspacing
Same backspacing + different widths = different offset

This is why backspacing is SOOOOOO much easier to deal with when you are working on a Jeep. A 15" wide wheel with 3" of backspacing is going to be the exact same distance from your suspension components/frame as a 4" wide wheel with 3" of backspacing. If you've got a bigger tire with more bulge in the sidewall then get something with LESS backspacing.

GENERALLY SPEAKING... the inside of the wheel is the important part on a Jeep. Sure, if your setup is too wide with too little backspacing, and you actually wheel your Jeep, then you can have issues getting into your fenders when you are flexed out.

Keep it simple. Life's easier that way. I feel like the debate about how to make these measurements comes up way too often and it's always someone trying to flex their muscles about how smart they are since they can do simple math. Doing it all based off of offset calculations is like a young engineer that's never gotten his hands dirty but wants to prove his concept with math vs the backspacing route being an old callus-handed farmer just knowing what works. HAHA!

So tell me why, given 2 tires @ 12.5 inches wide, on 2 wheels with the same +37mm offset,
one wheel @ 7.5" wide and the other wheel @ 8.5" wide, the dimension of the tire to the inside of the Gladiator does not change? See attached pic and tell me what is wrong.
The only change is the backspacing, not the clearance of the tire to the control arms or shocks.

 

[LostWoods]

You likely won't need to replace wheel studs to use them but nobody here can answer that question unless they have the setup you desire - wheel thickness at the seat varies across the board and the only way to know is to try it.

But really, just say no to shitty spacers. They're fucking dangerous and cause more issues than they're worth. Buy the right wheels or go with actual adapter-type spacers.

To tie it into the conversation, offset is not comparable unless the wheels are the same width, as was stated. The only measurement that matters within reason is what backspacing directly measures so you can either work with offset and wheel width to see what you need or you can just convert each to backspacing and use that measurement. Try to keep the backspacing less than what your stock wheels have to maintain clearance with lifts.

Adding width with the same offset adds equally to both sides, adding width with the same backspace adds width only to the outside. If your new wheels are 15mm more positive on the offset and wider, you are going to have issues because you are both moving the wheel inward and adding width to the inside.

 

[LostWoods]

So tell me why, given 2 tires @ 12.5 inches wide, on 2 wheels with the same +37mm offset,
one wheel @ 7.5" wide and the other wheel @ 8.5" wide, the dimension of the tire to the inside of the Gladiator does not change? See attached pic and tell me what is wrong.
The only change is the backspacing, not the clearance of the tire to the control arms or shocks.

Because tires are not a perfect shape. The width between the beads determines the maximum width (and height as well) of the tire. A wider wheel spreads the bead outward and the sidewall extends out with it until you get to a point where the wheel itself is wider than the tread. If you go up an inch in wheel width, I'd expect roughly the same gain in total width of the tire as wheel width approaches the tread width.

Go look at at tire before and after it's installed on a wheel. Before, the sidewall is generally barely wider than the tread. Once it's installed on an appropriate wheel and inflated, the sidewall will push outward significantly.

Sponsored