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Discussion Starter #1
Can someone explain the whole backspacing & rubbing scenario to me?

I know the smaller the number in backspacing you have, the further the wheel will stick out. Isn't it better to have something that sticks out when putting a larger size tire or will that make it rub things more?
 

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truck ~n~ tow
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If the wheel sits too far inboard...
...it can rub the frame rail

If the wheel sits too far outboard...
...it can rub the fender's outer sheet metal radius.

The idea here... is to get the wheel to be centered
in between both those negatives.

The proper back spacing is the best neutral that minimizes rub of either.
Otherwise trimming the fenders sheet metal outer lip...
...may be the only other way beside glass fenders.

Narrower tires fit easier and with less modifications to the fender wells...
...then wider tires...

When a wheel/tire is compressed and the steering is turned
If it is too tall... it can rub various points inside the fender well
Primarily caused by the axis of the inner/outer lugs of that tire during its turning radius.
Wider tires exaggerate/amplify the issue.

^ I'm not sure if I've given a proper understanding...

so I'll leave you with a coupla' links... and hope for the best :D

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

http://www.trailslesstraveled.com/viewarticle.php?id=63&catid=42
 

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Discussion Starter #3
Thank you TacoDell.....I think I understand better now. So possibly a 4" Backspacing would be the most ideal. The wheels I just bought have 3.25" BS. Ehhh, whatcha' gonna do

What happened is I bought 5 8x15 Wheels one of which had a brand new 33x12.5 BFG KM2 on it. I'm trying to figure out what tires size to buy and how to proceed with suspension etc. I plan on getting some Icon Extended Travel coilovers unless I can get away with something else and save some money. But, that's for another thread etc. In here I was basically trying to understand how backspacing affected the whole rubbing(the bad kind :D ) business.
 

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Thank you TacoDell.....I think I understand better now. So possibly a 4" Backspacing would be the most ideal. The wheels I just bought have 3.25" BS. Ehhh, whatcha' gonna do

What happened is I bought 5 8x15 Wheels one of which had a brand new 33x12.5 BFG KM2 on it. I'm trying to figure out what tires size to buy and how to proceed with suspension etc. I plan on getting some Icon Extended Travel coilovers unless I can get away with something else and save some money. But, that's for another thread etc. In here I was basically trying to understand how backspacing affected the whole rubbing(the bad kind :D ) business.
a 33x10.5 will net you a less headache fitting, but not with that backspacing. There are tons of posts about fitting a 33x12.5 on here.
 

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truck ~n~ tow
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Thank you TacoDell.....I think I understand better now. So possibly a 4" Backspacing would be the most ideal. The wheels I just bought have 3.25" BS. Ehhh, whatcha' gonna do

What happened is I bought 5 8x15 Wheels one of which had a brand new 33x12.5 BFG KM2 on it. I'm trying to figure out what tires size to buy and how to proceed with suspension etc. I plan on getting some Icon Extended Travel coilovers unless I can get away with something else and save some money. But, that's for another thread etc. In here I was basically trying to understand how backspacing affected the whole rubbing(the bad kind :D ) business.
3.25" is going to be too much outboard...
with a 33" 12.50 it will make matters worse to impossible.

Generally these trucks roll best with 4" - 3.75" BS'ing
OEM is 4.50"

In some cases with folk running a 33" 12.50...
they have pushed the BS'ing out to 3.50"
But most that I see... end up cutting the radius of the outer fender
to make accommodation for that BS'ing

You could lift yer junk higher... so that the tires would clear...
but that's just the wrong approach IMO.

I run 295/75/16's currently...
I have 4" BS'd wheels...
but the 295's are taller and wider then my previous 285's

so... I plan to add a 1/4" wheel spacer to keep that off the frame better.
But hope I don't end up having to radius the outer fender lip
to make that fit properly.

In yer case... a spacer cannot fix your dilemma.
And tho' you might make fitment with a narrower tire...
It's my guess these particular wheels you have...
are going to make nothing but a headache for you.

I'm also going to guess that the wheels you purchased...
Likely came off a chevy...
Chevy is hub centric... whereas the Toyota's are lug centric.

I personally would not attempt to interchange those...
nor expect them to fit the Toyota without issues.

Some will swear they have... and with little issue...
But I'm not buying into that jive.

Good luck with whatever you choose to do...
But if it were me...
I'd sell what you have... and do things right.
 

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Discussion Starter #6
Thank you for the advice TacoDell....taking the time to explain it all to me and not just spating out a opinion loaded one liner.

All this stuff certainly takes time to learn....I think I've got majority of the rest of it down. That is for the Suspension area though. I'm sure I'll be posting a couple questions up there as I plan on moving forward with the progression of my truck(slowly but surely). Your replies & opinions are informative and most welcome
 

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Discussion Starter #7
a 33x10.5 will net you a less headache fitting, but not with that backspacing. There are tons of posts about fitting a 33x12.5 on here.
Thanks Hoss...

I think I will stay with 31x10.5 for now as I'm getting a set that's already on the Mickey Thompsons I'm getting in trade for the Eagle Alloys.
 

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for all that was said, which is correct, I can tell you from what I've installed on my 1994 and 2004. The best combination for the 1994 was the 33x12.5x15 on 15x8 and a 3.75 in backspacing.

The 2004 best rode on 16X8 with the 4.5 BS and 265/285-75s. 15" were good but hard to find more than a 4" BS. Track was punched out and torsion bars gave way to coil-overs.

Current Tacoma's are just bigger but with much wider tracks. As I've tried the stock 5.25 BS rims, that will need nasty spacers to deal with wide tires, then to a 16x8 and 4.5 BS and 285s, that worked 60% of the time. Heavy and tight trails caused the tires to hit plastic trim hard. Some was trimmed but will not cut metal (4.0-4.5 BS with 315's). Ultimately though I needed something more tucked in without inner or outer rubbing.

To conclude, current set-up is an FJC 16x7.5 +15mm offset (around 4.75 BS) with 285s and 1st gen mudflaps, to me, to be the best compromise.. Included is the FJ and Tacoma Baja 16x7.5 with +10mm fake bead-lock mags... my take.
 

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so... I plan to add a 1/4" wheel spacer to keep that off the frame better.
Dell, did you add a 1/4 inch spacer yet? I've been looking for info on this, not too much out there on opinions for these thin spacers.

What kind did you get?
Stock wheel studs?
Different lug nuts?

Whatever info you you have...

Thanks
 

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truck ~n~ tow
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Dell, did you add a 1/4 inch spacer yet? I've been looking for info on this, not too much out there on opinions for these thin spacers.

What kind did you get?
Stock wheel studs?
Different lug nuts?

Whatever info you you have...

Thanks
No I haven't done anything with it yet.
still intend to...
but a .25" spacer will require I extend my lug bolt(s) thread
and I've just been too lazy to follow thru with that.

Dependant on the thickness of the wheel's hub (center chunk)
You may not need extend the lug bolt's thread...
and may be able to alternatively use ET (extended thread) 60* conical lug nuts in compensation.
8 - 10 turns with the lug nut on the stud/bolt
should offer enough security.

My particular wheel center is too thick if adding a .25" hub spacer...
as I already utilize those type of lugs for fitment.

Wheeler's Off Road sells the correct .25" hub spacers I think.
you want to use spacers that are lug centric

Of my understanding... Toyota Matrix lug bolts fit
and are the necessary length needed for extension of the lug threads.
But I haven't looked into that with any detail as of yet.

Tho' I think I read somewhere that someone else had. :dunno:

stuff to read... if you haven't already

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

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Thanks for the info.

I called AP. They don't have 1/4" spacers. I believe the smallest they carry is the 1 1/4" wheel adapters. They referred me to Wheelers.

I tried one for the hell of it because I was ordering stuff there anyway. Didn't really work. With the thick Pro Comp hub section, I could only get about 5 turns on the lug nuts (ET style). Also, the spacer is somewhat loose on the lug nuts and so it won't center perfectly. I think if the hub section was smaller and you used the ET lug nuts, it might still center it, but maybe not. Maybe having it perfectly on center isn't that critical?
 

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truck ~n~ tow
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I called AP. They don't have 1/4" spacers. I believe the smallest they carry is the 1 1/4" wheel adapters. They referred me to Wheelers.

I tried one for the hell of it because I was ordering stuff there anyway. Didn't really work. With the thick Pro Comp hub section, I could only get about 5 turns on the lug nuts (ET style). Also, the spacer is somewhat loose on the lug nuts and so it won't center perfectly. I think if the hub section was smaller and you used the ET lug nuts, it might still center it, but maybe not. Maybe having it perfectly on center isn't that critical?
oops... sorry... was thinking Wheeler's but typed AP

I really don't know how critical that .25" spacer fitment on the lugs is.
I would think it should fit fairly tight with minimal play.
But then... I haven't installed them yet.

If it has excessive amount of play and does not stay centered
on the hub... It could give some balancing problems.
But if the play in the holes only allows them to turn slightly on the hub's surface, but still stays centered... shouldn't be an issue.

I've seen some in the past that have some oblong holes
so that they will fit other lug bolt patterns.
As long as the oblong hole(s) don't have play in the lug holes vertically,
allowing any up and down (vertical) movement on the hub...
it should work fine.

But it sounds like you'll need longer hub studs.
 
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