Backspace for rubicon VS other models

[5foot19]

So I know that many lift kits ask for wheels with a BS of 4.75-4.5 or less to make sure sure there is no clearance issues. Normally these guides dont typically specify different backspacing for the same lift on which model JLU. When I look at something like this, it indicates that the rubicon has axles that are 1.5 inches wider (so .75 inches more clearance per side). Does this mean a rubicon with wheels, with a 5 inch backspacing, has as much or even slightly more clearance as a sport or sahara with wheel with 4.5 inch backspacing?

I like having my wheels poke out a little, but I prefer a hint/tease of tire poking out rather then a couple inches, so I want to meet the need without it poking out farther then needed. If 5 inches on my rubicon will give me as much clearance as 4.5 on other models, will that not give me the clearance needed while putting a little less stress on the driveline?

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[shekmark]

I also find this confusing even after researching. I went with AEV wheels and they have 5.77, which is probably more than most. AEV supposedly did lots of research on handling etc and came up with this and they say it works on all their lifts. I have about an inch of poke with my 12.5 wide tires ( labeled 12.5 , actual I never measured) . I have a 2 in lift and dont feel any rubbing

 

[5foot19]

I feel your pain Shekmark, I just don't understand the claims/needs for backspacing that gives 2+ inches of clearance then OE wheels. Do some lift springs maybe have much wider coils?

 

[shekmark]

I feel your pain Shekmark, I just don't understand the claims/needs for backspacing that gives 2+ inches of clearance then OE wheels. Do some lift springs maybe have much wider coils?

No I think some lower control arms are more straight and tire hit them. Taller tires would also hit things. I am only tunning 35s so no issue.

 

[sourdough]

Rubicons have wider axles. AEV JL wheels with 5.77 B.S. and +25 offset works with 37x12.5r17 Cooper Pro STT and a Mopar lift. Turn the steering stops out 1/4” and modify rear wheel liners with a hair dryer and you are good to go. Shorter 37” tires like BFG work even better with this set up.
I never have been a fan of 4.7-4.5 B.S. wheels on a Wrangler. The tires sticking outside the fenders allow, sand, gravel even road spray to be slung on the body and just looks wrong IMHO. Also with generic wheels, the tire won’t tuck into the fender liner when it’s stuffed. The extra expense of after market liners is not required with AEV JL wheels which are engineered to fit a Wrangler with 12.5 wide tires. They also offer better wheel bearing and ball-joint life. Moper’s lift isn’t for extreme rock crawling but for most folks it works and 37’s are pretty much the limit for a Wrangler D44.

wheel stuffed with steering at full lock steering.

 

[Jerrybizzle]

17x9 +12 on my rubicon with 37x12.5 17 and the mopar lift. Rubbed a little bit on the inner fender liners in the rear at full flex but not enough to be bothersome. Have motobilt inner fenders now and the fronts rub a little in extreme situations off roading. Setup tucks up in to fenders vs rubbing on the fenders with a -12 offset 9 wide wheel. Don’t poke much.

 

[MarkY3130]

I’ve posted this a few times but seems relevant here as well.


I have a Rubicon with 37x12.50 tires with the mopar simulated beadlocks which have a 5” backspace. The issue occurs at full stuff on one side of the front, with the tire at that location turned all the way in. It presses the sidewall into where the sway bar link attaches to the sway bar.

This is with the Metalcloak end link which is quite long and puts that connection point up pretty high. It may be possible that shorter end links may clear the tire.

The trade off of some kits like the AEV (or any kit that doesn’t have long travel springs and long shocks) compared to the MC kit is much less articulation (MC has 30” shocks), and with that you need longer links to keep your sway bar from flipping.

Ultimately I sold the mopar simulated Beadlock wheels and went with something with less backspacing. No problems now.

As another data point, I did not have the issue when I had those same wheels, with 35x12.50 tires, with only a 1” spacer lift and the stock sway bar end links.

The problem with many forklift clearance checks and articulation trailers is the wheels are straight. Turn those tires full lock and you’ll find more clearance issues.

 

[shekmark]

I’ve posted this a few times but seems relevant here as well.


I have a Rubicon with 37x12.50 tires with the mopar simulated beadlocks which have a 5” backspace. The issue occurs at full stuff on one side of the front, with the tire at that location turned all the way in. It presses the sidewall into where the sway bar link attaches to the sway bar.

This is with the Metalcloak end link which is quite long and puts that connection point up pretty high. It may be possible that shorter end links may clear the tire.

The trade off of some kits like the AEV (or any kit that doesn’t have long travel springs and long shocks) compared to the MC kit is much less articulation (MC has 30” shocks), and with that you need longer links to keep your sway bar from flipping.

Ultimately I sold the mopar simulated Beadlock wheels and went with something with less backspacing. No problems now.

As another data point, I did not have the issue when I had those same wheels, with 35x12.50 tires, with only a 1” spacer lift and the stock sway bar end links.

The problem with many forklift clearance checks and articulation trailers is the wheels are straight. Turn those tires full lock and you’ll find more clearance issues.

And that would be a big deal I’m sure, for serious rock crawlers. I think, for me, green and blue trails four or five times a year, my setup is good. My Dynatrac 2 in lift probabuy doesn’t flex nearly what your MC does. I did just order a MC rear diff skid!

 

[MarkY3130]

And that would be a big deal I’m sure, for serious rock crawlers. I think, for me, green and blue trails four or five times a year, my setup is good. My Dynatrac 2 in lift probabuy doesn’t flex nearly what your MC does. I did just order a MC rear diff skid!

Totally agree. The situations where it becomes a problem are pretty limited.

 

[MarkY3130]

That is the reason I did not go with a MC lift. Flex is beyond my trail needs (I don't do extreme)and 4.5 BS wheels are recommended for tire clearance. 4.5 BS wheel have tire poke past the fenders and will not stuff without a fender chop and after market liners. Plus lift cost is higher specially with the aftermarket fender liners

I haven't chopped my fenders and the tires stuff into the fenders fine (rubicon) with the 3.5" backspacing wheels I have. I did replace my rear liners but for sure the 3.5" backspacing have less clearance issue in the back than the 5" wheels I used to have did. Moving the tires out actually helps with clearance in the wheel well as long as you can clear the lip of the fender.

I had to cut the rear corner of the tub in the rear wheel well. Tires were hitting it pretty good. That is more a function of tire size, bump stop amount, and control arm length than it is with wheel backspacing.

I'll try and find some pics or video of the tires stuffed into the fenders

 

[MarkY3130]

Here’s a couple from a very rainy day on Holy Cross

 

[MarkY3130]

Removing the liners is a fender chop. Cutting the tub is also something I have not had to do with 5.77 and +25 AEV wheels and 37" tires.

I’m not going to argue semantics, but I don’t think most would call a liner change a fender chop. Now that I’m on the 3.5” wheels I don’t need the rear aftermarket liners. Still have my stock fronts on.

Cutting the tub has nothing to do with the wheels as I mentioned above. Your control arms must be set shorter or you run a lot of bumpstop. Most likely just shorter control arms.

 

[David P.]

I’m a little confused. I’m thinking of running a Mopar lift next month on our new JLUR with 37x12.50x17s. I don’t want to kill the ball joints too fast, would prefer somewhat tucked tires, but no preference there. I’d really like no rub at full turn or the rare occasion of full flex, but am open to some liner trimming/melting, etc.

What target backspacing and offset should I look for on a 17x9 or 17x8.5 wheel?

Lighter the wheel / tire combo the better.

 

[David P.]

What backspace are your wheels? What brand wheels/tires?

17x9 +12 on my rubicon with 37x12.5 17 and the mopar lift. Rubbed a little bit on the inner fender liners in the rear at full flex but not enough to be bothersome. Have motobilt inner fenders now and the fronts rub a little in extreme situations off roading. Setup tucks up in to fenders vs rubbing on the fenders with a -12 offset 9 wide wheel. Don’t poke much.

 

[Jerrybizzle]

What backspace are your wheels? What brand wheels/tires?

Mine are 17x9 +12 offset. They work great but do rub a little bit at full stuff off road. I think the perfect offset would be about 0 on a nine inch wide wheel for rubicons. They are gfx tr 10 wheels from discount tire. Normal price is about $115 a wheel I think but with Black Friday or a holiday sale I got them at $100 per wheel. Tires are 37x12.5 17 mastercraft mxt

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