Question regarding offset drivetrain wear

[LLRubylady]

I’m trying to increase my knowledge so bear with me. Most aftermarket wheels I see are negative offset. My tire man says that it’s not good for wheels to be further out because it increases wear and can cause instability. But if they made the rubicon axles wider wasn’t that the thinking to accomodate the larger tires and offsets? I thought the wider stance was better?
I have -12 rims on now. I don’t notice any stability issues.
These forums are a tank of great information.

Sponsored

 

[TheEddie]

Wider axles are good, wheels that have a center that sticks out further than stock increases leverage on components (wheel bearings, axle Cs, axle housing etc.) and also impacts your scrub radius (bad things).

 

[AnnDee4444]

I'm not sure if anyone knows for sure why the Rubicon axles are wider, but I can make a few guesses: Since the Rubicon's sway bar disconnect allows for more flex, more clearance was needed at the top of the compressed side. This could have been accomplished with wheels that have more negative offset, but the engineers likely already determined that the steering geometry was optimized, which is why the Rubicon and Sport/Sahara have the same offset. A wheel with more negative offset wheel will also take up more space when turning lock-to-lock (it would rotate in an ark, rather than in-place), which could be more problematic with larger diameter tires also. Since the Rubicon gets different axles and fenders anyway, making them wider was likely minimal cost, and could be sold as a premium option.

Technically, the least load on a wheel bearing (for the rear) would be a wheel with 0 offset, since the loading would be equal on either side of the wheel. The front axle is not the same scenario, but I suspect that there is actually less load at 0 offset than OEM, since the increased scrub radius also means that the tire will roll when steering lock-to-lock, rather than fighting traction by rotating in place.

I would hardly call -12mm extreme offset though (especially since it is closer to 0 than OEM), and would be more concerned with other parts of the steering system & ball joints long before the wheel bearings.

Here's a top-down view that might help:

 

[AnnDee4444]

Here's a top-down view that might help:

I just noticed that the image I attached contradicts what I stated, about how a larger scrub radius is easier to turn. I should clarify that I was referring to steering when the vehicle is stopped or at very low speeds, whereas the image is referring to high speed turning stability.

 

[LLRubylady]

I am just wondering what I can expect as far as increased wear and tear on what parts. There are many folks driving around and wheeling with bigger tires and negative offsets so maybe I have nothing to worry about with the 7000 miles a year I will put on my jeep. But I like to know what I'm getting myself into.

Sponsored