The ole backspace question

Guys,
I’ve been a member here for a few years. I remember finding threads all about tire size wheels and backspacing.
Maybe someone can point me to that thread because I cannot seem to find it.
My setup,
2015 DCLB
2.75 OME LIFT WITH 885’s and new Dakar’s new upper control arms.
At the moment I’m running 285/70R17’s on stock wheels with 1.25 wheel spacers.
I’m due for some new tires, and I want to eliminate the wheel spacers and go with new wheels. 20x9 rockstars with 4.53 backspacing. Is this the correct size back spacing to eliminate the wheel spacers?

Thanks in advance for any and all responses.

 

What’s your current wheel width and offset?

 

Knowing offset is easier but.... i think 4.5 is still on the high side

 

Running stock wheels at the moment with 1:25 wheel spacers

 

I’m just having a hard time wrapping my head around it.

 

That’s didn’t answer the question. Do you not know the width and offset? 4.5 backspace should be fine, the 20” wheel may more of an issue, you may need less offset because of that. Knowing your current width/offset will help determine if the outer lip of the wheel you want go to will be sitting in approximately the same spot.

 

Not sure what the stock wheel offset is.

 

Got it. It definitely would help knowing. If you get it. Post it.

 

https://www.tacomaworld.com/forums/wheels-tires.15/

 

To get a good answer, everyone would need to know what you current stock wheel backspacing, or wheel width & offset is. I quickly googled 2015 stock wheels and it looks like only two 17" wheels were offered for 2015s. They were both 17x7.5 with +30 offset. That width/offset combo converts to 5.43" backspace. So, with your 1.5" spacers, your backspace right now would essentially be 5.43-1.5= 3.93". If my Google guess of what your stock backspacing is correct, your proposed new wheels will have a difference in backspacing of .6" (.6" less the wheel will be pushed out, .6" more in backspacing value).

Whether or not that'll work for your setup, I dont know. Honestly, I don't know shit about 20s and potential issues fitting those.

With 4.53 BS your wheel won't be pushed as far out anymore, which decreases the likelihood of rubbing on your cab mount/firewall, but you are a little closer to your UCA, coilover, spindle, etc (typically less of an issue compared to contacting your cab mount/firewall).

I recommend you figure out exactly what your backspace is for your stock wheel and provide that here for feedback. Also, if you wheel, why not just stay in the 16-17" wheel range? You could find one to eliminate the need for spacers. 20s aren't really wheels for for wheeling. However, if it is just the look you're after and it's a street truck, than do what makes you happy.

If my assumptions are correct, and you want to run the same backspacing you are now without spacers (or within .1" of it), than seems like that wheel is not what you're looking for.

 

@EatSleepTacos @singletrack_ftw

Perhaps you could provide a better answer

 

Backspacing is really the only spec that matters then wondering if you’ll rub on suspension components or not. 4.5” or less is fine for 285s so to answer your question, yes those will be fine. That said, a 9” wide wheel will give you rubbing issues at the firewall/cab mount. An 8” wide wheel with 4.5” BS is ideal for 285s.