35" vs 37" Tires (and lift) on a JLRU for Daily Driver at 70-90 mph

Beaching631

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Well, the stock wheels are 17x7.5 with +44.5 mm offset. Offset indicates where the mounting surface of the wheel is, in relation to both the face and back of a wheel. Zero offset would be dead center. The higher the number gets on the positive side, the face of the wheel will get flatter. The higher it gets on the negative side, the more sunken in the face gets.

To maintain the factory distance between the wheel and frame, you'll want the extra 1.5" of that 17x9 wheel on the outer face side. 1.5" = 38.1mm. 44.5mm - 38.1mm = 6.4mm.

All that means you'd want nothing higher than a +6mm offset wheel.

One of the many things told to me since I was a very young child, is that the only thing dumb about a question is not asking it.

Cheers!
Great explanation thank you!
So negative offset: more of the wheel is outside center of rim, positive offset: more of wheel is toward the inside of rim. So even with the 9 inch wheel I would be fine getting a zero offset wheel because the Stock wheels are 44.5mm positive offset.
I guess my only question is why are the stock wheels so positively offset on the JLUR? Are the brake lines, etc so fragile that they require that? And has anyone run into problems with debris screwing things up after going to a zero or negative offset 9 inch wheel?
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Headbarcode

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Great explanation thank you!
So negative offset: more of the wheel is outside center of rim, positive offset: more of wheel is toward the inside of rim. So even with the 9 inch wheel I would be fine getting a zero offset wheel because the Stock wheels are 44.5mm positive offset.
I guess my only question is why are the stock wheels so positively offset on the JLUR? Are the brake lines, etc so fragile that they require that? And has anyone run into problems with debris screwing things up after going to a zero or negative offset 9 inch wheel?
Glad I could help. Yes, you are spot on with the positives and negatives. And yes, a 0 offset would give you another near 1/4" of wheel to frame clearance over the +6 I previously mentioned.

The factory offset keeps the tires tucked in and under the fender. This not only keeps the body sides cleaner, but makes the vehicle compliant across multiple countries and the individual states within. If memory serves, both Connecticut and Pennsylvania will fail a vehicle inspection of tires are poking.

There's also the mechanical reasons, but that will make offset conversation seem like child's play. If you're interested, explore scrub radius. Just bring a change of clothes, because you'll be there for a while.
 

Headbarcode

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@Beaching631 Forgot to answer your last part.

My pic you originally quoted is of an earlier version of my Jeep. I'm now on 17x9 -12 wheels wrapped in 38x13.50's. Yes, any tire poke will result in dirty sides. More poke, more dirt.
 

Beaching631

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Glad I could help. Yes, you are spot on with the positives and negatives. And yes, a 0 offset would give you another near 1/4" of wheel to frame clearance over the +6 I previously mentioned.

The factory offset keeps the tires tucked in and under the fender. This not only keeps the body sides cleaner, but makes the vehicle compliant across multiple countries and the individual states within. If memory serves, both Connecticut and Pennsylvania will fail a vehicle inspection of tires are poking.

There's also the mechanical reasons, but that will make offset conversation seem like child's play. If you're interested, explore scrub radius. Just bring a change of clothes, because you'll be there for a while.
Awesome, can't thank you enough for the help!
I was more concerned about debris on the inside messing up connections at the wheel, not too worriesd about mud, etc...although extra flying pebble scratches would suck
Now I just have to pull the trigger on the wheels and tires. Hopefully there's a market to sell stock Rubicon wheels and tires with 11k on them.
I notice you are also from L.I. Me and my two sons, age 12 and 9 (every once in a while the wife too), are on the outer beach at Smith Point, Cupsogue, and Shinnecock most of the summer. Say hi if you ever see us! We have a granite metallic color JLUR.
Thanks again!
 

Headbarcode

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Awesome, can't thank you enough for the help!
I was more concerned about debris on the inside messing up connections at the wheel, not too worriesd about mud, etc...although extra flying pebble scratches would suck
Now I just have to pull the trigger on the wheels and tires. Hopefully there's a market to sell stock Rubicon wheels and tires with 11k on them.
I notice you are also from L.I. Me and my two sons, age 12 and 9 (every once in a while the wife too), are on the outer beach at Smith Point, Cupsogue, and Shinnecock most of the summer. Say hi if you ever see us! We have a granite metallic color JLUR.
Thanks again!
Oh, some of the seemingly sensitive wheel end bits. Honestly, I've yet to hear or read about anyone having any damage to brake lines, abs cables, etc. Not saying it's impossible, but it'd be like winning the unlucky lottery. Damage to the body is far more common.

List your stock wheel and tires in the members marketplace section. There's definitely a healthy market for them. The other listings will give you a range of what to ask for.

My nephew has worked the summers at smith's point, over the last couple years. This summer, he was working the toll booth for driving out on the beach.

I'll keep an eye out for you, so if you see a bearded guy waving you down from a StingGray JLUR, that'll be me not some random lunatic.
 

MARSHMELLA

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I’m on dirty life bead locks, 37/12.50/ 17s. -12 offset, 4.5” backspace. Travel sometimes an hour or two on freeway to get to wheeling destinations. At 75-80 mph, like being in a car. I can’t pinpoint why it drives so good, could be the tire/rim combo, or my Frankenstein lift I honestly don’t know. Here’s how much they stick out. I realize not everyone has the same taste in rims but I’m really impressed by these bead locks, they balanced out with not much weight. They’re a little heavier than most rims, maybe that has something to do with it, it’s above my pay grade.....:)

84307A8E-CF58-4B49-BC0D-0C8269767AEC.jpeg
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Greetings Rocky!
Your rig in these photos look perfect to me. I’m about to lift and add 37s myself.
Does this wheel and tire combo mount in the spare space ok? How about the rear camera, does the camera stick all the way out?
Thanks!

P.S. what is your lift method? Is it a comfortable lift?
 

Roky

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Greetings Rocky!
Your rig in these photos look perfect to me. I’m about to lift and add 37s myself.
Does this wheel and tire combo mount in the spare space ok? How about the rear camera, does the camera stick all the way out?
Thanks!

P.S. what is your lift method? Is it a comfortable lift?
Hi Kirt .....

Yes you can put that wheel on factory cattier, I ran it on there for several months. I’ve since gone to an EVO mfg. tire carrier. It replaces the factory hinges, not just reinforce them. I wheel the crap out of my rig and the factory carrier rattled a lot. Here’s pic of the camera, the evo carrier has you use factory camera bracket and location. It just has a different third brake light assembly.
C5328815-443A-4B3B-A2DB-6902C93C2408.jpeg


Here’s a link to my build page, it explains everything I’ve done up to now.........:)

https://www.jlwranglerforums.com/forum/threads/crystal-rubi-build.61821/

What part of Florida?
 

MARSHMELLA

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Hi Kirt .....

Yes you can put that wheel on factory cattier, I ran it on there for several months. I’ve since gone to an EVO mfg. tire carrier. It replaces the factory hinges, not just reinforce them. I wheel the crap out of my rig and the factory carrier rattled a lot. Here’s pic of the camera, the evo carrier has you use factory camera bracket and location. It just has a different third brake light assembly.


Here’s a link to my build page, it explains everything I’ve done up to now.........:)

https://www.jlwranglerforums.com/forum/threads/crystal-rubi-build.61821/

What part of Florida?
Awesome! Thank you for the info. I’m going to check out your build.........
Oh, I’m in the Pensacola area.
 

cool_it

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Wish I would have read this chain earlier.
I bought the 37s SST's and 2" lift for my JLUR and it looked perfect but for a daiy driver in PA it was challenging. Everytime I hit the construction zone it was a white knuckle experience. Those that drive PA 78 look know what I am talking about. This time around I'm trying 35's. The 37's x 13.50 always found thier grooves so I am hoping the 35's x 12.50 behave differently.
 

Zandcwhite

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A 37x12.50 fits on the stock wheel exactly like a 35x12.50. We did a budget 2.5" spacer lift with shock extensions and 37's right before our moab trip. 1,100+ miles each way, cruise control set at 85mph for the majority of it. Rides great, handles great, plenty of power. Since that trip we have upgraded a few things. New shocks, for more travel not because the factory ones didn't work or handle the larger tires. New steering stabilizer with relocation kit because we smashed the old one on a rock in big bear. 1.5" wheel spacers as the tires did rub on the lower control arms a bit at full lock. We also went with the Yokohama geolander x-mt, one of the heaviest and most aggressive 37's on the market. An AT or hybrid tire would have even better handling characteristics.
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20210103_112857.jpg
 

kkuntz01

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Wish I would have read this chain earlier.
I bought the 37s SST's and 2" lift for my JLUR and it looked perfect but for a daiy driver in PA it was challenging. Everytime I hit the construction zone it was a white knuckle experience. Those that drive PA 78 look know what I am talking about. This time around I'm trying 35's. The 37's x 13.50 always found thier grooves so I am hoping the 35's x 12.50 behave differently.
I've got a curious question, what PSI were you running in your tires? Asking as I've been running 37x12.50x17 Cooper STT Pro's with a 2.5" budget boost basically since I took delivery in 2018. The only time I've ever had a handling issue is when the PSI climbed above optimal, between 34-37 on my junk. Mostly I try to keep things in around 32psi (your sweet spot may be different) and it's ridden like a dream everywhere we've driven.
 

cool_it

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Mine were between 32-34psi. I tried lower as well but was annoyed with the low-pressure lamp and wasn't much better. Unfortunately, I added the lift, adjustable track bar, steering stabilizer, and tires at the same time. Immediately noticed the steering pulling to the right and had everything aligned and it was still in spec. Don't get me wrong, I didn't mind the tires, but driving 36k miles in 20 months, some drives as long as 10 & 12 hours straight. In the end, I probably should have gone with 35" which is what I am about to do on my replacement Jeep.
 

kkuntz01

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Mine were between 32-34psi. I tried lower as well but was annoyed with the low-pressure lamp and wasn't much better. Unfortunately, I added the lift, adjustable track bar, steering stabilizer, and tires at the same time. Immediately noticed the steering pulling to the right and had everything aligned and it was still in spec. Don't get me wrong, I didn't mind the tires, but driving 36k miles in 20 months, some drives as long as 10 & 12 hours straight. In the end, I probably should have gone with 35" which is what I am about to do on my replacement Jeep.
While I won't discount the possibility the tires could be playing a part in your issues, it's a possibility you may have something else going on in your suspension/steering that is causing and/or contributing to your issues. Purely spitballing, but inclined to think a geometry issue issue in one of those things.
 

damageinc321

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A 37x12.50 fits on the stock wheel exactly like a 35x12.50. We did a budget 2.5" spacer lift with shock extensions and 37's right before our moab trip. 1,100+ miles each way, cruise control set at 85mph for the majority of it. Rides great, handles great, plenty of power. Since that trip we have upgraded a few things. New shocks, for more travel not because the factory ones didn't work or handle the larger tires. New steering stabilizer with relocation kit because we smashed the old one on a rock in big bear. 1.5" wheel spacers as the tires did rub on the lower control arms a bit at full lock. We also went with the Yokohama geolander x-mt, one of the heaviest and most aggressive 37's on the market. An AT or hybrid tire would have even better handling characteristics.
20210103_100849.jpg
20210103_112857.jpg
Are those the pics with the 37's and wheel spacers?
 
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