For those that dont understand backspacing and offset

[98layinframe]

Alot of people on here keep asking about how to measure backspaing and offset, so heres a pic i had.

The correct or should say best offset for our trucks is 0 - 4 mm offset.and the best backspace is:
4" with a 7" rim
4.5" with a 8" rim
4.75" with a 8.5" rim



feel free to add extra rim sizes and widths if you want.

EDIT! I was looking at my original post, and now realized why it is confusing some people, the offset desired will change for the width of the rim. I posted a 0-4mm offest... I should of posted this

7" --- 0 - 4mm
8" --- 4 - 10mm
8.5" --- 5 - 15mm

now these are just approximations, the wheels you chose can vary from these measurements a little and still work.

[acrofobia]

and backspacing determines offset

[edthegm]

so will 15x8s with a 4 inch bs work on a stock 2002? i'm looking at putting 235/65R15 on them.

[acrofobia]

4x4 or 2wd?

[BigLarryT]

So how can u determine all of this information(backspacing-offest)? I bought a couple set sof wheels off of buddies and I don't know any of this info. Ths first set was off of my buddies '86 Z-28. The wheels are 15x8. I put a set of 235/60R15 BF Goodrich Radial T/A's on them. I have a slight frame rub and the inside wheel weights shear off. so i'm guessing i'm a lil snug in there. So how do figure this info OUT!?!?

[acrofobia]

Measure the backspacing of them wheel, to me it sounds like it tucks too much if your getting frame rub

[edthegm]

mine is a 2wd.

[ffbrass]

how is 0-4mm offset correct for our trucks if an 8" rim with 4.5"bs has 12.7mm of offset?

[98layinframe]

total backspacing, including offset ... basicly to put it simple terms .. on our trucks the mounting flange should be about right in the middle of the wheel

13mm = 1/2" so..

[ffbrass]

lol.....so? Im asking cause I dont understand. The charts on the site and you suggest that an 8" wheels should have 4.5" of bs. That means the flange is 13mm offset from center but you also said our trucks should only have 0-4mm of offset.

[low2000s10]

ok so will a 19x8.5 with a 35 offset fit?

[ffbrass]

why is it that some wheel co. dont even list their wheels with the bs included? I was looking at the Foose Spank 5's and you can get them (18x8) with an offset of 19mm or 34mm. So is 19mm = 4.75bs and 34= 5.34bs? and also why is it that some wheel co. list the wheels with bs and offset???

[slammed2001]

SIZE AND SPECIFICATIONS: All four rims are the same size on this set.

17" x 9" (+26mm, 6.11" backspace). They are 5-lug (5 on 4.5).


are these going to fit decently or are they going to be a pain in the ass? I have no clue on wheels and spacing and such. This will be on a 4/5 drop

[98layinframe]

Quote: Originally Posted by slammed2001

SIZE AND SPECIFICATIONS: All four rims are the same size on this set.

17" x 9" (+26mm, 6.11" backspace). They are 5-lug (5 on 4.5).


are these going to fit decently or are they going to be a pain in the ass? I have no clue on wheels and spacing and such. This will be on a 4/5 drop

you will need a 1" - 1 3/8" adaptor to run those wheels, the backspaceing is wrong, but that is a good thing, cause the bolt pattern is wrong also... so the adaptor will take care of that. those wheels have a 4.5" bolt pattern, our trucks have a 5.75" pattern.

[the buddman]

Quote: Originally Posted by 98layinframe

you will need a 1" - 1 3/8" adaptor to run those wheels, the backspaceing is wrong, but that is a good thing, cause the bolt pattern is wrong also... so the adaptor will take care of that. those wheels have a 4.5" bolt pattern, our trucks have a 5.75" pattern.

5 x 4.75

[98layinframe]

whops... sorry.. that was a typo.. jeesh

[98SS]

I thought I could contribute a bit here. That diagram in the first post shows a negative offset, if I'm not mistaken. You guys may have covered that in the posts that followed, but I haven't read it all.

Anyway, here's one that shows Positive offset, which (also to my understanding) is what our stock rims have.

[98layinframe]

correct you are.

[98SS]

Thought it would help everyone visualize the characteristics of the wheels.
Glad I could help.

[98layinframe]

EDIT! I was looking at my original post, and now realized why it is confusing some people, the offset desired will change for the width of the rim. I posted a 0-4mm offest... I should of posted this

7" --- 0 - 4mm
8" --- 4 - 10mm
8.5" --- 5 - 15mm

now these are just approximations, the wheels you chose can vary from these measurements a little and still work.

[Kevs10]

Quote: Originally Posted by Tims98SS

I thought I could contribute a bit here. That diagram in the first post shows a negative offset, if I'm not mistaken. You guys may have covered that in the posts that followed, but I haven't read it all.

Anyway, here's one that shows Positive offset, which (also to my understanding) is what our stock rims have.

Guess I don't quite have it right yet.... I can only get Eagle 211's here with a 4" or 4.75" backspacing (17 x 8's) and I know the 4" BS will stick out too much because I tried some 16's @ 4" BS and they moved the tire out quite a way.... The 4.75" BS version will solve that problem but maybe go a little too far the other way by insetting the rim too much - but does the +2mm offset that they have built in, do anything toward bringing the actual rim centreline close to the 4.5" BS that I probably need to make these wheels fit my S10?
My dad also wants to get a set of these 17's for his 1968 Z/28 which only has rallys with 43/8" - 4.5 BS - are these Eagles going to come close with this type of BS and offset numbers or will the tire sit inwards too far compared to the rallys?
Why do many of the manufacturers not make 4.5" BS anymore if many vehicles, S10's included, require them and a 4" or 4.75" won't work well?

Thanks -- Kevin

[98layinframe]

4.5 and 4.75...... there is only 1/4" difference. if you get the ones with the 4.75" backsacing they will fit just fine. as for your dad, have him take one of his wheels off and measure the backspaceing on his wheels, im not sure if camaros are excatly the same.

[DROPTSBLAZE]

It might not be exact w/ the Camaro but it will be pretty close. My dad used to swap rims w/ our old S-10 and my mom's '72 Nova. And I swapped rims w/ my S-10 and my bro's '79 Malibu.

[98layinframe]

well you are correct and wrong at the same time the earlier camaros thru 92 had the same owheel ffset as our trucks, so the earlier wheels do fit on our trucks just fine. The newer gen camaros have a higher offset wheel, so no they are not going to fit correctly without an adaptor. All camaro and s10's have the same bolt pattern so the wheels will physicly fit on the truck, but they will look dumb sticking in like that, and also your turning will be shit.

[thestickboy]

Question for you experts on offsets. Will a 20" x 8" wheel with a 5" backspace work. The website that I am ordering from says that will fit an S10 but is that too much backspacing.

[98layinframe]

yes they will fit, the only thing with the 5" backspace, is that when turning you might rub pretty good on the frame and inner fenders. you would most likely want to run a 1/2" spacer with those wheels.

[thestickboy]

I don't think there is enough room on the studs to allow the nut to go on with a 1/2" spacer. I have a set of 1/4" spacers so I will try them first. Wheels are on order. Thanks

[98layinframe]

Quote: Originally Posted by thestickboy

I don't think there is enough room on the studs to allow the nut to go on with a 1/2" spacer. I have a set of 1/4" spacers so I will try them first. Wheels are on order. Thanks

no there is not enough room, there is barly enough to fit a 1/4" spacer on there safely. Im running a 1/2" spacer on my truck currently, but i also called up summitracing and ordered a complete set of longer drag racing studs, they are 1" longer then the factory studs. they were 40 bucks, so it wasnt an expensive upgrade.

[IOWABOB]

Quote: Originally Posted by edthegm

mine is a 2wd.

4" will work fine-

[IOWABOB]

Quote: Originally Posted by edthegm

so will 15x8s with a 4 inch bs work on a stock 2002? i'm looking at putting 235/65R15 on them.

I had 15x8 with 4" backspace on mine, it worked fine_ (96 S10)

[mmxxiii]

Here's a page that explains backspacing and offset pretty well. It's oriented to f-bodies, but the info is still relevent.
They also sell billet adapters/spacers.
http://www.skulte.com/adapterfaq.html

[DROPTSBLAZE]

some good info on that site...nice find