Wheel Backspacing and Offset Info

The FJ wheels that measure 16x7.5 +15mm?
Are you lifted?

 

Yes I have 6112s at the top setting.... so about 2 to 2.5 inches.

Its these wheels...



I just powder coated them black. I like the offset with the 1.25 spacer and the 265/70-17s. I'm doing a CMC, and I'm sure they would be fine on the inside at the UCAs. Just not sure about the area above the cab mount.
Thanks

 

Option #3 would clear.

This guy is running 295/75/16 on the FJ rim without a spacer and 2" lift w/ SPC UCA's.
It's about 3/4" taller and 1/2" wider than what you have planned.
He clears suspension and just barely rubs on compressed turns; not enough to justify a CMC.
https://www.tacomaworld.com/threads/295-75-16s.518783/

I'd go with option #3...
-285/75/16 on a 16x7.5 +15mm(without spacer) is pefect, IMO; doesn't change the scrub radius
-285/75/16 has a rim width range of 7.5"-9"; measured rim width of 8"
-option #2 only pokes 1/2" more than option #1; not a make or break deal at that point, considering they both include 1.25" spacers

If you decide you want more stance, because it will poke about 3/4" less than your current set-up, you could always add the wheel spacer later.
If you do, it will add 1.25" of positive scrub radius; same as your current set-up.
Whether it would clear or not...hard to say.

 

No shit. I’m thinking all I want is 285’s and maybe 1/2” past the flares and now I’m in the fetal position with drool on my face!!!

 

Thanks!

So the stock OR wheels with the spacer should approximately place the tire at the same place as a zero offset pro wheel... Just in a different way. I think I may go with the OR wheels and spacers for the 285s.

Even though the FJ wheels would work best, I like them better and want to keep those clean and straight for road use. I don't mind beating up the ORs.

 

I didn't realize you were going to use one set for street, and the other for offroading.

What size tire do you plan on using with the FJs?

 

I have some 265/70-17 Ridge Grapplers on them already. Kind of another reason I want to use the OR wheels for the 285 MTs... I would have stripped sold the tires and used the FJ wheels if the OR wheels were going to be too much hassle to make work for the 285s.

My biggest issue is that I'm running out of time. The Red Clay Rally is a couple of months away and I still need a couple of skids, install and wire some lights, need to do the CMC and get some tires. If I can get away without having to beat my pinch weld in and doing the waterproofing involved with that... it will help me out.

We plan on running the optional difficult routes and the other guys on my team are in Jeeps on 35s. I'm trying to get the truck set up so that I won't be "that guy"... LOL.

 

Sorry but I tried to go thru this entire thread and find my answers but couldn’t...

I am trying to run 17x8.5 6x5.5 with 0 offset and 4.75 backspacing on a stock sr5 2wd...with 265 70 r17 tires. Will this setup work without a lift? If not, what adjustments do I need to make??

 

The tire will poke 1-3/8" more than stock.
The rim will poke 1-3/4" more than stock.
The tire is 1" greater in diameter .

Turn your wheels until you have the least amount of clearance.
Fab something up that is a 1-3/8"x1/2" rectangle. This will give you a feel for the 1-3/8" of poke and 1/2" of radius increase.
Place it on the corner of your tire.
Turn the wheel in and out to see where it might be a problem.
Give yourself a safety margin to account for suspension compression.

Differences in tread design can affect the mock-up.

You might be able to squeak out a little more caster to help clear.

My gut says you'll rub.
I'm on 16x7 +25mm(same as SR5) and 265/75/16(same overall diameter and width as 265/70/17) with stock offoad suspension.
I barely clear under extreme circumstances(suspension compressed, in reverse uphill, with wheels turned) I am confident if I had 1-3/8" more tire poke, I would rub a lot more often.

Sorry I can't give you a more straight up answer; too many variables.
Best you could do is find someone with that exact setup.

 

@splitbolt thanks. I’m new to all this so I appreciate the info!

So if I change the offset will this help so it doesn’t stick out far? I’m guessing not...

 

Ok. So, I’ve read a ton of these threads and posts and I think I have an idea of what I need but gonna run my thoughts by y’all and see what you think. The goal is to run 285/75/16’s on my ‘18 4x4 SR5 Tacoma. So this is my current plan. RC 3 inch lift using the upgraded shocks on the front instead of the spacers. So 3 inch lift, aftermarket American a racing wheels that are 16x8 with 4.5 backspacing and 0 offset. Should this set up have minimal rubbing and have a nice stance (stick out slightly from the fender for a nice aggressive stance) or is this gonna rub like hell and end up being a nightmare and have to cut? This will be my first lifted truck so I’ve been stressing and doing as much research as possible but figured I’d ask the guys that know best from experience

 

Excuse my ignorance with wheels and tires, got an OME lift all around on my access cab and want to get new wheels and some 285s. Whats the best wheel I can get with proper backspacing to avoid getting spacers?

 

4.5" or less of backspacing.

Examples of 4.5" backspacing
-7.5" rim width with +6mm offset
-8" rim width with 0 offset
-8.5" rim width with -6mm offset
-9 rim width with -12mm offset

IMO, 8" rim width with 0 offset is the 'best' choice.
-it is the 'measured rim width' for 285s
-not so wide as to give too much poke and less clearance problems at the cab mount/pinch weld(no guarantees though)
-lots of choices in the aftermarket

 

Thanks for the reply, this is invaluable!!!!

 

I forget, what limits the backspacing? My first set of aftermarket wheels were 18x9+0 (5" bs) with 305/60r18. Had some minor fender trimming to do, but no issues rubbing on the suspension.

 

Suspension...
18x9 +0(5" BS)with 305/60/18 gives 1/2" more tire clearance at the suspension than a stock 2008 Sport 17x7.5 +30(5.5") with 265/65/18.

The other 1/4" or so of width difference can be reconciled in the differences between tire size vs 'measured rim with'.

9" is the 'measured rim width' of a 305/60/18.
8" is the 'measured rim width' of a 265/65/17; not 7.5" as is the stock '08 Sport.

 

That's basically the same results I came up with. So I would have to ask why everyone says 4.5" bs or less, when 5" seems to be acceptable for 285's.

The section width only changes 0.2" per 1/2" rim width.

 

I can only tell you why I recommend 4.5" backspace for 285s.
-8" are more popular and available than 9"
-8" +0 is more available than 8" +12
-8" is the measured rim width for 285s
-safety margin for aftermarket UCAs
-safety margin for different tire 'shapes'

 

Makes sense. I only ask because I'm running aftermarket UCAs. Perhaps they offer more clearance than stock. With the 305s I had, they came very close to the UCA at full droop.

I haven't seen much of any aftermarket wheels offer positive offsets for our trucks. 0, -6, and -12 seem to be common. Btw, the numbers in your post are really for 16" wheels

 

This is true...I'm somewhat 16"-centric.