Help with backspacing doubt

[Don Bulee]

Hello, I'm about to get new 35s for my 06 Rubi, and the search has been narrowed to this wheels (since my moabs will rub in the control arms and I don't like spacers)

https://www.extremeterrain.com/mammoth-boulder-bl-charcoal-15-8-J100624.html

(I think they look good and are cheap)



but the problem is that they are available in 15s and 16s with the 15s having 3.75in of backspace with -19mm offset and the 16s having a 4.5in backspace with 0mm offset, so.... I was thinking in getting the 16s so in the future I'll be able to get the big brake from Mr Blaine, but so far with my current 285s (33s) the BMB pads and rotors have been more than enough... so maybe the 15s will be okay for my needs and the big brake won't be needed... anyway..... for the MT Baja Legend MTZ 35x12.50s the 4.5in of backspace of the 16s would be enough for not having rubing against the control arms or I should just stop messing around and just get the 15s with the 3.75s of backspace which (according to my understanding) will be enough backspace for not rubbing.... thanks..!

Ps. one of the pros of getting the 16s is that I can get the wheels now and keep my 33s until I get more money for the tires (a few months).... with the 15s I would need to spend all at one time....

Ps2. I usually wheel at rocks, mud, and daily driver

 

[JMT]

Not on your options, but I’d go with 17’s.

 

[Don Bulee]

Not on your options, but I’d go with 17’s.

the 17s that looks kinda cool are at least more than 80 bucks more expensive that these ones... but, what would be the reason for 17s instead of 15/16s?

 

[Apparition]

the 17s that looks kinda cool are at least more than 80 bucks more expensive that these ones... but, what would be the reason for 17s instead of 15/16s?

More tire availability on 17’s

Also I have a 16” BBK in my 15” wheels, can’t confirm they all work though.

 

[Don Bulee]

But the Mickey Thompson MTZ are available for 15s and 16s... Beside that, is there any other reason to go with the 17s? And... Would the 4.5in of backspace with 0mm off set for the 16s be enough for not rubbing?

 

[Mike_H]

But the Mickey Thompson MTZ are available for 15s and 16s... Beside that, is there any other reason to go with the 17s? And... Would the 4.5in of backspace with 0mm off set for the 16s be enough for not rubbing?

Probably not. I'm running 4.0" backspacing and 35x12.5-17 tires. They rub my control arms and swaylock links.

 

[Don Bulee]

Probably not. I'm running 4.0" backspacing and 35x12.5 and rub my control arms and swaylock links.

Thanks.. That’s what I was looking for.. Then I would get the 15s with 3.75"

 

[Rickyd]

I don't understand why mammoth adds more and more backspacing as the rim size grows. In that lug pattern it just doesn't make sense to me

 

[Mike_H]

I don't understand why mammoth adds more and more backspacing as the rim size grows. In that lug pattern it just doesn't make sense to me

Agree. It’s very tough to find 17” wheels with decent backspacing for our rigs

 

[JMT]

But the Mickey Thompson MTZ are available for 15s and 16s... Beside that, is there any other reason to go with the 17s? And... Would the 4.5in of backspace with 0mm off set for the 16s be enough for not rubbing?

More tire options in 17”.

16’s poor for tire choice. 4.5” bs would not be enough. I have run a 4.5” bs with a .25” spacer and it drove great on the road. I added two washers to the steering stops and the rubbing off-road was acceptable (35x12.5r15)

Now I run 3.75” bs and my Mickey Thompson Legend MTZ’s (35x12.5r17) still rub some on my Swayloc when off-road. I’m not worried about it though.

Even when I had 3.625” bs (33x12.5r15) I had rubbing on the upper spring perch. It’s irrelevant. Don’t worry about it. You have to compromise somewhere.

You can do a 10.5” wide tire with slightly less backspace. My happy spot is 3.75” bs with 35x12.5r17

 

[psrivats]

Agree. It’s very tough to find 17” wheels with decent backspacing for our rigs

Gets even more tougher when you add the condition of "good looking and fits within the design language of a TJ".

 

[psrivats]

I don't understand why mammoth adds more and more backspacing as the rim size grows. In that lug pattern it just doesn't make sense to me

They make what sells. And most people buy for looks/tire poke and do not really understand what is needed for good steering.

 

[Don Bulee]

More tire options in 17”.

16’s poor for tire choice. 4.5” bs would not be enough. I have run a 4.5” bs with a .25” spacer and it drove great on the road. I added two washers to the steering stops and the rubbing off-road was acceptable (35x12.5r15)

Now I run 3.75” bs and my Mickey Thompson Legend MTZ’s (35x12.5r17) still rub some on my Swayloc when off-road. I’m not worried about it though.

Even when I had 3.625” bs (33x12.5r15) I had rubbing on the upper spring perch. It’s irrelevant. Don’t worry about it. You have to compromise somewhere.

You can do a 10.5” wide tire with slightly less backspace. My happy spot is 3.75” bs with 35x12.5r17

Thanks man.. That was the answer/knowledge I was looking for...