I read somewhere that 2nd Gen backspacing is 3 5/8". I've seen folks with aftermarket wheels putting backspacing of 4 3/4" and other sizes on. Can someone explain backspacing and offset in layman's terms? What effect will 4 3/4" backspacing have on rubbing while turning or full stuff.

I'm :confused: about this subject.

Thanks.

 

Roger Brown has graet diagrams on his site for visual learners like me.

Backspacing and offset explained.

In these illustrations the right side is the inside of the wheels.

More backspacing puts the tire in closer to the center of the truck. More offset makes the tires stick out farther and makes the fronts more likely to rub on the back of the fender.

 

Hi Cebby,
I have solid axles on my landcruiser and an 85 Toy 4x4. The backspacing is about 3 3/4 inch (maybe less, but this is the most I can install). The backspacing on those cool SR5 mags on a newer toy is about 4 1/2. I bought and mounted tires, and tried to install. Too much backspacing ment the wheel was setting closer inboard than orig wheels. Found out the wheel was pressed TIGHT into the tie rod end and wouldn't rotate.

To measure the backspacing on a wheel:
1. Lay the (usually) shiney side down
2. Place a straight edge across the open back (rim side to side, not the tire)
3. Measure distance from mounting surface to the straight edge



____________________ <------ straight edge
]........./\......... [
\______\/_____/ <-------wheel
/.................... \

The distance from /\ to \/ is the backspacing

To little backspace moves the tire/wheels out away from the vehicle, too much moves it in.

 

OK, then does anyone know the most offset you can get for a 2nd gen runner?

 

Wow - that was some good reading. Thanks guys.

I'd like to know the answer to that also, except I want to know the max backspacing that won't interfere with the suspension components.

Let's see if I understand all of this info correctly: If I keep my stock backspacing, but go up in width (from my stock 15x7 alloys) to maybe 15x8 or 15x9, all of the width increase would be on the outside (face) of the wheel. This will likely cause fenderwell rubbing at full lock, not to mention interference when going for full stuff.

Am I on the right track?

 

Cebby, I have 2nd gen. Running 15x10 Centerlines with 5" backspacing and 32x11.50 BFG AT's. No rub. Used to with Cepek FC 31x12.50 only at full turn. I do have a 1 1/2" lift.

 

Cebby I have zero probs with my 15X8's. Did I read somewhere you finished your Aisin conversion? I think my modding just got put on hold. Watch CNN you'll know why.

 

Joey - all I have to say is Holy ˟˟˟˟˟! We civilians are forever in your debt. Give 'em hell. Kinda makes the Yotatech mod mania seem trivial.

Yep, finally got the hubs done. They look pretty good and work great. I need to take a road trip to see if it improves acceleration/gas mileage. I've had to leave them locked since we keep getting socked with snow.

Back to the backspacing question. If I go to a 8" wheel, what backspacing should I use? What about a 9" wheel? If a 10" is 5" BS, (with 1.5" lift), is a 9" - 4.5"BS? What about an 8"?

 

Well Cebby, you dog, I finally got my Aisins on my rig. Mod #2 (yeah, I'm a big time Toy modder)
Only thing is, I didnt freeze my tail off outside, I brought it in to work. Got PAID to install my hubs INSIDE @ work! YEAH!! How ya like me now Cebby???? That nasty frostbite clear up ok?

(for those who dont know, I sent some goons to Cebby's to slow him down on the hub conversion.... only they went to the wrong house and beat-up poor Mr. Tinsdale across the way.)

Next step, the digi camera and some pics.....

 

- even if it is off-topic.

I now understand the difference of backspacing vs offset and the effect each has on wheel fit, but I am still looking for what the recommended backspacing is for wider wheels. I obviously want to minimize rubbing and will be adding probably another 1 1/2-2" of lift prior to getting new wheels.

 

Hi everyone! This is actually my first post ever! I'm trying to find out what the best off-set/back-spacing is for my 1976 TLC. I have heard 3.5 inch back-spacing in optimal, but I would like to put some new wheels on and notinced that everything is measured in off-set now-a-days instead. What OFF-SET is optimal? Like many others, I wanted to put the new FJ Cruiser wheels (17X8) on my '76 FJ40 but have been told that the 15mm of off-set they come with is too extreme for my application...and I don't want to use wheel spacers as they cost $400.

Thanks to anyone that can help shed some tech light on this!

~JOHN

 

I know this post is old but I thought i'd give the corrected link for those of us that are using the search feature.

Backspacing/wheel measurements explained: http://4crawler.com/Diesel/Tires.shtml#WHEELS