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Perfect Wheel Backspacing for 37's on 2" Lift - Rubi Diesel Axles / Fenders

ajkaz

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Happy Tuesday! Whats the perfect recipe for backspacing for most 37's to keep them from hitting when turning but to minimize wheel stick out. Hoping to find the happy medium. Shopping for wheels right now, and moving up.

I have the Kenda Klever 35x10.5 and love them, but.... I should have went bigger form the beginning... My wife even asked why "I bought such small tires." I'll likely move to the Klever in a 37.
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i don't know the backspace, but in my opinion the perfect offset for 12.5 width tires is +25 on the wide axles. outside of the wheel should run flush to the outside of the fender flare
 

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i don't know the backspace, but in my opinion the perfect offset for 12.5 width tires is +25 on the wide axles. outside of the wheel should run flush to the outside of the fender flare
Agreed, ideally on a 8.5" wide wheel.
OP, if you go to AEV's site you can see what they will look like as all their builds with 37" tires are on 17x8.5 wheels with +25 BS, there are other brands of wheels with the same size available also.
 

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ideally on a 8.5" wide wheel.
Doesn't really matter. One of the reasons i prefer offset over backspace is the width of the wheel is (almost) meaningless. Since the tire and wheel share the same mid-line, they also share the same offset regardless of wheel width.

I run 315s at +6 on a 17x9, but a 315 at +6 on a 17x8 would have the exact same amount of poke.
 

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I like 0 offset/4.75BS 17x8.5" for 37's on wide track axles, but they do poke out a little bit.

I have found that when you put longer shock on the maximize droop and trim bump stops for max up travel, the +25/5.72" wheels can get into the inner fenders and some remote/piggy resi shocks at full stuff.

If you are just going to do an off the shelf lift with short shocks and tall bump stops, either will work fine.
 

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i always find it interesting that people refer to 0 offset on a 12.4/12.5 width wheel as "minimal poke"

I run 12.4s at +6 and put XR flare extensions on mine because I did not like the amount of poke, and that's a quarter inch less than 0.

Just funny how taste influences perceptions. i see +6 as too much poke, whereas others see 0 as very little poke.

To each their own!
 

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i always find it interesting that people refer to 0 offset on a 12.4/12.5 width wheel as "minimal poke"

I run 12.4s at +6 and put XR flare extensions on mine because I did not like the amount of poke, and that's a quarter inch less than 0.

Just funny how taste influences perceptions. i see +6 as too much poke, whereas others see 0 as very little poke.

To each their own!
Might depend on the tire design too? Some have more sidewall tread than other and that would make it appear wider.

I was balancing extreme flex and shock clearance with tire poke. If you are willing to relax or more one of those items, you can get by with much less. RIght now I've been playing with the SDi E-Clik shocks and they really need 4.75 to use full turning angle.

I knew I didn't want it like my YJ where 40% of the tire is outside the fender!

The front vantage point is not great, but the rear shows almost the entire tire tread being inside the fender? 38x12.50 Ridge Grappler.

Jeep Gladiator Perfect Wheel Backspacing for 37's on 2" Lift - Rubi Diesel Axles / Fenders 20220830_160023
 
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ajkaz

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Thanks for all the feedback! Looks like factory wheels with a 1.5" spacer would be +6 offset, correct? I'll likely go this route for now.

@Rahkmalla do the XR flares seem to cover the poke at +6? I want to keep as much debris off the front doors as possible.
 

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@Rahkmalla do the XR flares seem to cover the poke at +6? I want to keep as much debris off the front doors as possible.
You'll get more gunk kicked up from underneath the fender (the gap from the end of the fender to the floor) than you will from the fender being too narrow. I'm also looking into these though, I like the tucked look and I get about 2-3-inches of poke (ha!).
 

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i don't know the backspace, but in my opinion the perfect offset for 12.5 width tires is +25 on the wide axles. outside of the wheel should run flush to the outside of the fender flare
I don't really understand how these measurements work and every time I look into it just ends up making my head hurt. Mind posting pics of your setup?
 

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Thanks for all the feedback! Looks like factory wheels with a 1.5" spacer would be +6 offset, correct? I'll likely go this route for now.

@Rahkmalla do the XR flares seem to cover the poke at +6? I want to keep as much debris off the front doors as possible.
6.25" BS factory minus the 1.5" spacer is 4.75" BS? Puts you right at the edge of the fender with a 12.50?
 

Rahkmalla

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I don't really understand how these measurements work and every time I look into it just ends up making my head hurt. Mind posting pics of your setup?
0 offset means the wheel connects to the hub at exactly the centerline of the wheel. So for a 9inch wide wheel, 0 offset means backspace is 4.5 (half the width of the wheel). Offset is measured in millimeters. So +6 offset means the point where the wheel connects is 6mm towards the outward face of the wheel (moving the tire inward). 25.4mm to an inch, so 6mm is roughly a quarter inch.

So why do people prefer one measure over another?

If you're trying to stuff as much wheel/tire as possible in as tight a package as possible measuring directly for the limited amount of space you have just makes sense. Too little backspace you can rub suspension components!

If you're trying to match poke between different wheels, offset is preferable. Because offset is a centimeter measurement off the mid line and wheels and tires share their midline, they also share their offset. So a 12.5 tire on a +6 17x7.5 wheel will poke out a tire the exact same amount as a 12.5 tire on a +6 17x9.5 wheel.

But in reality, most people just feel the most comfortable with whichever measurement they learned first. I'm an offset guy personally. Mechanics tend to be offset guys. Wheelers and truck guys tend to be backspacers. I think tuners tend towards offset but wouldn't bet the house on it.
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