9" wide wheels that poke, and Rubi sized tires - Not digging the ride?

[DDXDesign]

So as I showed in a couple threads, I was very happy to find these cool black MT Classics on 285/70/17 Rubicon-sized tires and snatched them up. I love the way they look on the JLU. But I do 90% highway driving - north to DC for work, south to Quantico to visit my girl, etc - and I've just found that with every highway trip I take, I dislike them a little bit more.

Now, bounce and shimmy I totally know to expect from a Jeep (I've had a couple JKs before this JL), but this setup has surprised me, being really crashy over bumps and such, and feeling a lot more side to side tossing than stock as well. So, knowing that so many people either have a Rubi or put the Rubi shoes on their other trims of JL, and not reporting such, I wonder what is different with these at the same size.

- Is it the fact that the wheels sit farther outboard? They have a -12mm offset, 9" wide, can't remember the backspacing but they poke a bit.
- Is it that I've got too much air in the tires? They're at 37lbs.
- Is it somehow an alignment thing? Seems to track fine even though I get tramlining on some pavement (expected with wider tires tho)
- Something I missed?

I am not opposed to changing the setup again if need be (I really love the wheels but would not mind dropping a tire size if needed, for instance), but it's just made me curious to find out why I don't love these.

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[ChattVol]

So as I showed in a couple threads, I was very happy to find these cool black MT Classics on 285/70/17 Rubicon-sized tires and snatched them up. I love the way they look on the JLU. But I do 90% highway driving - north to DC for work, south to Quantico to visit my girl, etc - and I've just found that with every highway trip I take, I dislike them a little bit more.

Now, bounce and shimmy I totally know to expect from a Jeep (I've had a couple JKs before this JL), but this setup has surprised me, being really crashy over bumps and such, and feeling a lot more side to side tossing than stock as well. So, knowing that so many people either have a Rubi or put the Rubi shoes on their other trims of JL, and not reporting such, I wonder what is different with these at the same size.

- Is it the fact that the wheels sit farther outboard? They have a -12mm offset, 9" wide, can't remember the backspacing but they poke a bit.
- Is it that I've got too much air in the tires? They're at 37lbs.
- Is it somehow an alignment thing? Seems to track fine even though I get tramlining on some pavement (expected with wider tires tho)
- Something I missed?

I am not opposed to changing the setup again if need be (I really love the wheels but would not mind dropping a tire size if needed, for instance), but it's just made me curious to find out why I don't love these.

Try airing down to 30psi and report back...37 psi is too much

 

[Uhdinator]

Door jam PSI is for the max cargo capacity listed. Airing down a bit will help.

 

[DDXDesign]

Quickie update - I aired down to what turned out to be 32 PSI (local gas station's gauge on the air pump is inexact) and it's a much more comfortable ride, at least! Still lost some of its pep so I might still change out the setup some, but the crashy feeling is gone =0) Thanks!

 

[Pig-Pen]

your wheels have 4.5" backspacing fyi

 

[DDXDesign]

your wheels have 4.5" backspacing fyi

Yep, i finally found the spec again, 4.53" BS on these.

 

[BuffaloBill]

I haven’t had any personal experience with a Wrangler having aftermarket wheels yet, but I’m about to. Still waiting for my JLUR to arrive but will be running a 315/70 K02 on an 8.5” wide +25mm offset wheel.

I like the look of a stance a little wider than stock, but was concerned about sticking the wheels out too far. One reason being mud, rock, etc thrown by the tread poking out. The other reason for the possible handling change due to a change in scrub. I’m hoping others who have actually run different offsets to chime in with their experiences.

I did some measuring on another stock JLUR equipped with the 285/70 K02 (on a dealer lot actually). Holding a strait edge (wooden yardstick) vertically along the sidewalls, up to the underside of the plastic fender, the fender stuck beyond the sidewall bulge an average of 1/8” on the front and 1/4” on the rear.

Measuring from the outer edge of the fender to the edge of the outermost tread block of the tire showed an average on the front of 1 1/16” and 1 1/8” on the rear. I say average because the front axle wasn’t perfectly centered with the suspension at rest on this one. I took this measurement by holding the yardstick vertically against the fender edge and measured from that to the tread edge.

The factory wheels I understand have a +44.45mm offset. The 315 tire is 30mm wider than the 285, so that will add 15mm to each side (so-to-speak). So If I use a wheel with +25mm offset the tread edge will extend outward like this (relative to the stock tire/wheel position):

44.45mm - 25mm + 15mm = 34.45mm or 1.36”

This should result in the tread edge poking .23 to .30” beyond the fender edges.

The outer edge of the rim would be outward 1.27” from stock position but I am more concerned about the tread position than the bead or sidewall position.

For different offset wheels, this 315 tire the tread would stick beyond a Rubicon’s fender flare by these amounts (based on the measurements taken off that dealer’s JLUR). I averaged the small difference I measured between front and back. I believe these numbers to make sense. Do these agree with real world experiences?

Wheel offset Tread poke
+25mm 0.263”
+18mm. 0.538”
+12mm. 0.774”
0mm 1.247”
-12mm. 1.719”
-18mm. 1.955”
-44mm. 2.979”

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