Backspace, the wheels not the keyboard.

toy yoda

toy yoda

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Looking at some of the Pro Comp steelies, I'm a little confused by backspacing concept. I'm used to 'offset' in millimeters on cars, have no idea how to convert that knowledge to how backspacing really works. Can someone help clarify?

To my understanding, my stock 5 stars have a 4" backspace and are 16x7. If I move to a 16x8 with a 4" bs that means the wheel will move out an additional inch, correct? I just want to choose a 16x8 wheel that will work well with my 99 tall coils and 265/75/16s. :thanks:
 
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Bootown is correct, the stock wheels have 4 5/8" backspacing. You are correct in that they are 16x7's.

If you move to a 16x8, with 4" backspacing, the edge of your wheel would site an additional 1 5/8" farther outboard than the stock wheels.

One of the best pages I found for explaining wheel specs is this one:

https://www.rsracing.com/tech-wheel.html

Offset and backspacing are related. A 16x8" wheel with 4" backspacing has a 0 offset, because there is 4" on both sides of the centerline of the wheel.

A 16x8" wheel with 5" backspacing has 1" POSITIVE offset, 1" = 25.4mm, so that wheel would have a +25.4mm offset.

The stock rims would work fine with '99 tall coils and 265/75's, and since you're wanting to move to an 8" width on the rim, you can carry that over to your new wheels... you could do a 16x8" wheel with any amount of backspacing, as long as it is less than the stock 4 5/8" I wouldn't go less than 4" though, or your wheels will stick out very far and might look kinda funny.
 
Thank you, and you other two as well. That really helps in relating the two measures. So I'm thinking the 4.25" bs for the pro comp 16x8's is maybe a little more aggressive than I need to go, considering I'm only on the 99 tall coil.
 
You may rub the UCA. I was close with my 3.75" Bs 16x8" wheels when i ran 285's. worst case you run a 1/4" wheel spacer

And thans for searching and reviving :) I like too see this happen
 
Brilliant said:
Doesnt fish run 4" BS with 285s?

This is the best diagram and explanation of BS & offset I've found.

Tech Knowledgebase - Wheel Backspacing and Offset
Click to expand...

I know exactly how Back spacing works, That has a nice picture. im just saying from my experience, Its hit and miss. A LOT HAS TO DO WITH TIRE MODEL. Some tires (MTR, Km2's) have large lugs on the sidewall and they may hit. and keep in mind a 7" wheel will make a 285 skinnier than a 8" wheel. so someone may have no problems with 285's on a 16x7 with 4" bs and then someone will rub with 16x8 4"bs and the same tires. I was about 1/4" from my 285's with the 3.75 bs 16x8s The closest point is usually at full droop. And when i switched to 315s i needed to shave the uca's about 1/2" and run 1/4" wheel spacers and still rub a little at full lock full droop

Here is a good database maybe it will help you out. TTORA - Tire and Wheel Fitment - Faq
 
Brilliant said:
^ thats a great reference, but how does the tacoma reference apply to 4runners?
Click to expand...

Same front end....... Same UCA, same brakes on the 16" model. Same clearance. So if it fits a taco it will fit your 4runner. Make sure your looking at the pre 05 list
 
Wheel Spacers...?

Seems like the folks on this thread are in the know, so I pose this question here...

I have a 1998 T4R and over the summer I bought a set of used American Racing Rally rims with the same 16" size and bolt pattern as my truck has...

Great condition, good look, decent price...but they do me no good as the front calipers do not fit inside of them...close, but no cigar...

I am wondering if anyone knows if either 2 or 3" wheel spacers would work as a cheat to get these rims bolted on my truck - and if so, what sort of other issues with alignment and rubbing could I possibly encounter?

It is likely that after the cost of the spacers, the rims would have cost me just as much as a correct new set...but it would save me the effort of trying to resell the ones I have, plus give the truck a wider stance...

Any information would be most helpful...Thanks!
 
Here is the deal, I would not run a 2" or larger wheel spacer they are too big. The most likely cause is that wheel has a thick inner part and its hitting the caliper. If its close to fitting you can measure how much more you need to go to fully mount the wheel, then buy appropriate spacers. I bet a set of 1" or 1.25" spacers would be plenty. You can also grind the caliper down just a hair to make them fit. You probably wont have too many issues with rubbing your firewall/pinchweld with the spacers as ong as your running 31's or 33's. You may have to get the BFH out and ben the pinch weld over


Trail Gear has nice spacers for about $90 bucks and they are having a sale so you could probably get them for $90 shipped.
 
Money is exactly right, I'm kinda puzzled why the rim won't clear but it can't be by much. A 1.25" max is probably good enough. Mostly just going to be you having to shave the caliper a bit and it should clear. Just get under there and see where its hitting. This is what I had to do to fits my 15" cragars.
 
I don't want to do this but I have to....From all of the information that I have gathered on wheels and spacing I think I want a 16x8 with a 4" backspacing but now I am coming to find that most steely wheel manufacturers don't offer this. Am I an idiot? Possibly. I have a 2000 Limited with the flares, SS1.2A and some 285's. I want the wheels to stick out past the fender (ever so slightly). I want a style like the ProComp series 52's but they seem to not be offered. I am missing something I know it. Any advice on wheels here?
 
I have an 8" wide wheel with 4.1" backspacing and 285s and its just about even with the flares. So 4" BS should put just a hair outside the fenders.

Also, stay the heck away from steel. Steel wheels are so heavy. When I went back to alloy from having steelies I could feel the difference in the weight of the wheel by how the truck performed. Less power to get moving and more efficiency.
 
4-Ripcord said:
I have an 8" wide wheel with 4.1" backspacing and 285s and its just about even with the flares. So 4" BS should put just a hair outside the fenders.

Also, stay the heck away from steel. Steel wheels are so heavy. When I went back to alloy from having steelies I could feel the difference in the weight of the wheel by how the truck performed. Less power to get moving and more efficiency.
Click to expand...

Interesting. I never thought about the weight being a major factor in all of this.... I am going to have to rethink all of this now. Thanks for all your help Rip I'm sure you're already tired of my questions.
 
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