Rim Offsets

[Bumbo]

I am a bit new to calculating how this is done...

The goal is basically to find a set of rims that would accomplish the same thing as just adding 1.25" spacers.

Currently I am running OEM 17" FJ Rims with a BFG MT 255/75/17 (32.1") tire.

17 x 7.5 J 15?

I was thinking of reducing the rim width by a small amount (0.5") to create a little more "bubble" on the sidewall. Essentially protecting the rim a little bit since I started enjoying a 255 which I plan on keeping.

What are you thoughts... and how do I figure out what backspacing / offset I need?

Alternately I could just add some spacers... but between two sets of spacers and the money from selling the FJ rims, I could essentially get close to the cost of just "doing it right".

 

[pipo6007]

Wheel Offset to Backspace Calculator | GTSparkplugs

 

[blackoutt]

So if you want to go skinnier by .5" and center that up, plus equivalent to 1.25" spacer you want your new wheel outside to stick out by 1" more than existing. Your ideal wheel would be 17x7" -17 offset. Good luck finding that! Most people run a 17x8.5 -12 or somewhere around there for a good fit on our rigs. Extreme pokers run those with spacers added. For your wants I would say simply add spacers.

Online Wheel and Tyre Fitment Calculator. Offset, Tyre Stretch and Speedo Error | Will They Fit

 

[Macallan]

Wheel / Tire Size Comparer

 

[Yota_Noob]

What [MENTION=117708]blackoutt[/MENTION] said. There are some negative offset wheels out there but they’re few and far between. I believe Konig makes a wheel or two for our rigs that are available in a negative offset. I had TRD pro 5th gen t4r wheels on my sr5 and they were just about even with the side of the truck as far as poke goes. If I remember correctly, those wheels had a +4 offset

 

[BackOff]

I had the same idea, more sidewall bulge to protect the rim. 16x7, -16 offset.
With the 285s I had on, my impression was that they are louder than the 16x8 rims they are on now. Made the flat of the tread area curved? Made my T4R vibrate all weird at slow speed on pavement. Not as much an issue with a narrower tire I would guess.

The steering felt a little heavier.

With the low lift I have, the 16x7 -16, was hitting the tires on the fenders and the front body mount.

Really messy in the wet...poking out.

Cops look at you.