offset and tire clearance

[hkusptac]

I have read recently on these forums a lower offset will create less tire clearance because of the wider turn arc it creates.... I am running a 0 offset with 285/70/17 k02s, fabtech crash bars. at full lock I can barely fit my pinky in between the rear bar and the tire, does this mean crash bar rubbing will occur during flex or has It barely cleared? I am however experiencing minor rubbing during flex + full lock. Cant tell if the rubbing is coming from the bar or the plastic block i may have to shave down a little. How much more clearance would a +15 or +25mm offset create? also wondering if the BDS or readylift beams offer more clearance, the design sure looks better and I am considering switching if it is possible.

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[Steve23]

I have read recently on these forums a lower offset will create less tire clearance because of the wider turn arc it creates.... I am running a 0 offset with 285/70/17 k02s, fabtech crash bars. at full lock I can barely fit my pinky in between the rear bar and the tire, does this mean crash bar rubbing will occur during flex or has It barely cleared? I am however experiencing minor rubbing during flex + full lock. Cant tell if the rubbing is coming from the bar or the plastic block i may have to shave down a little. How much more clearance would a +15 or +25mm offset create? also wondering if the BDS or readylift beams offer more clearance, the design sure looks better and I am considering switching if it is possible.

This https://tiresize.com/wheel-offset-calculator/ is super helpful for that

 

[hkusptac]

thanks very helpful. Im contemplating switching to an almost identical looking rim except it has a 12mm offset. My only hesitation is the rim is a few pounds heavier and a more expensive. According to the calculator, switching from a 0mm offset to a 12mm

The inner sidewall to the suspension and frame is:
0.47" Closer


The outer sidewall is:
0.47" Closer In

Curious if this will gain me a half inch of extra full lock clearance at the rear bar?

 

[Steve23]

thanks very helpful. Im contemplating switching to an almost identical looking rim except it has a 12mm offset. My only hesitation is the rim is a few pounds heavier and a more expensive. According to the calculator, switching from a 0mm offset to a 12mm

The inner sidewall to the suspension and frame is:
0.47" Closer


The outer sidewall is:
0.47" Closer In

Curious if this will gain me a half inch of extra full lock clearance at the rear bar?

I would think you'd want the inner side wall to be farther away to get more clearance, so a negative offset.

 

[hkusptac]

I would think you'd want the inner side wall to be farther away to get more clearance, so a negative offset.

Thats what I was thinking originally but according to others that may not be the case due to the wider turning arch it creates. hopefully some more people can chime in. I believe there is a sweet spot around 18-25MM. but hopefully some more minor modifications can make my current setup work. I really like the look and how it rides.

 

[Steve23]

Thats what I was thinking originally but according to others that may not be the case due to the wider turning arch it creates. hopefully some more people can chime in. I believe there is a sweet spot around 18-25MM. but hopefully some more minor modifications can make my current setup work. I really like the look and how it rides.

I got a guy @DukeCanBuildit

 

[DukeCanBuildit]

Thats what I was thinking originally but according to others that may not be the case due to the wider turning arch it creates. hopefully some more people can chime in. I believe there is a sweet spot around 18-25MM. but hopefully some more minor modifications can make my current setup work. I really like the look and how it rides.

Hey Teo,

How are things in the Kootenays? That’s a nice fat tire for a zero offset wheel. How much is your truck levelled/lifted?

If it’s not, I’d suggest 2 to 2-1/2 inch level or lift. It might just solve your problem. If you’ve already done that, then your offset is the culprit.

Our stock offset is +55mm, as you get lower, you push the tires out. When you get to zero or to a negative offset, you’re pushing them out WAY further. Offset is the distance from center of wheel to hub interface. Zero offset means the hub interface is at the centre of the rim. Negative means it is closer to the inside lip of the rim.

As you lower offset, you increase backspacing, allowing you to clear the knuckle - a good thing. At the same time, you push your wheels toward the wheel well and crash bars - it’s a delicate balance. Go too far out and you rub - a bad thing.

Most guys with stock wheels and 285s only use a 1/4” or 1/2” wheel spacer to poke the wheels out a bit while avoiding the crash bars. That’s like running a +50mm or +42mm offset wheel.

Guys with low offset wheels tend to solve rubbing issues by replacing the crash bars with Fabtech, BDS or ReadyLIFT crash bars.

You’ve ventured into that area of Zero or Negative offsets that sometimes requires a larger lift or can only accommodate certain brands of tires.

With that said, @OFC Ranger has 285/70R17s on a 0 offset. I’m not sure what he’s done with his crash bars but he should be able to help as well. I think it’s his tire choice that is saving his skin on this.

This picture explains what low or negative offset does. The horizontal lines represent the crash bars - the shaded tires show their pushed out position.

Here’s a helpful link - scroll down to read the definitions...

https://tiresize.com/wheel-offset-calculator/

 

[OFC Ranger]

With that said, @OFC Ranger has 285/70R17s on a 0 offset. I’m not sure what he’s done with his crash bars but he should be able to help as well. I think it’s his tire choice that is saving his skin on this.

I had ran stock wheels with 2.5" lift with Toyo OC ATII 285/70/17 without mods to crashbar. 0+ offset will require major cutting or removal.

 

[hkusptac]

@OFC Ranger Thanks for your input. I am running aftermarket bars but coming very close to rubbing on the rear. I am wondering if jumping up to a 12mm offset would make things better without having to jump to a 18mm or 25mm offset.

 

[OFC Ranger]

Dunno, but when I added 2" spacers it made my offset 5+ and I just took the bars out completely. Once I added RTR wheels and ditched factory wheels and spacers that put me at 0+ so I already know that requires them to be modified/removed.

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