Offset 101 For Dummies
 

http://img406.imageshack.us/img406/2783/offsets2fs4.jpg

Too much positive offset will make you hit your coilovers or chassis, the more negative offset you have will make your wheel stick out. Take note that the width of the rim plays a major roll on your offset. The bigger the rim the less room you have to play with offset sizes.

Conversion: 1 INCH = 25.4mm

example: 17x10 rim is 254mm wide (0 offset for that gives you 127mm sticking out and 127mm going in)

Mods sticky this?

Also please feel free to throw in some exact figures in here as far as whats the maximum clearance you have gotten from rim backspace. Thanks!

wow..

you have no life.. :loco:

best thread ever

I don't like the picture, but I understand it.

Everything could be clearer and concise.

be my guest!!! :bigok:

in regards to offset, i'm truly as noobtastic as they come, so this thread is helpful. thanks much.

Images are very crude but they work fantasmicly. Would suggest a little more info on our cars limits, but I'm not one to talk because I have no clue what they are. +1 for a good thread for the noobs.

Tire stretch also has a lot to do with fitment :D

Your still not that clear, thats why some people don't understand.

Let me help.

Your example for example: 17x10 rim is 254mm wide with a 0 offset means that the offset is dead center, so you have(254/2=127. You have 127mm front and back space. If this same rim was a +35 you would find the center line wich we already did its 127, now add 35(+35) (127+35= 162) now take that away from the total width(254-162=92) so our rim is 92/162 convert that (162/25.4=6.3 and 92/25.4=3.6) your rim is 10" wide with a 6.3" back space.

http://img252.imageshack.us/img252/6861/offsetke5.gif

This is not going to tell you what you can fit unless you know your car, I had a tool that would let me put a car on a jack and check the in and out clearance, but it grew legs. You can also use your stock to do the math on and then mesure from the front to see how it will line up with the fender

I think the original explanation is good enough for me. Call me a cave man but i got it :dunno:

a few said the didnt

his original picture is fine because it shows the relationship of the coilovers to the rim, very nice, post this in my suspension faq thread please, it's stickied

Just because you know they need it this should help in the noob quest to understand the mysterious offset problem that has been unanswered for far to long http://www.1010tires.com/WheelOffsetCalculator.asp

WOOOOHOOOOO!!!!

You should be required to take a test on this before you can post a wheel question.

http://www.raceandroad.com/images/ns...texplained.jpg
For the one below, hub is to the left.
http://kmhafer.datsun510.com/wheel_offset.jpeg

It can't get much simpler than that. Great write up!

That's awesome... Like, for reals.. +1 for you

Good Write-Up fo sho!

If this gets stickied and people post what fits is more/less flush on certain cars, that would be pretty awesome...Just for a refference...

S14
I rock a +0 17x8 Up front and its WAY FLUSH I have to have a fair ammount of camber because my front tires arent very stretched
I rock a +19 17x9 Out back with 225s and they are JUST stretched enough to clear stock fenders with no trimming, rolling, hammering(also a fair ammount of camber)

I would also assume with the above math you could calculate a good offset per the width of your rim...as in if you were to run a 17x10 out back on an S14 with say a 235 or 245 tire, you could probably run a -5 and it would sit fairly NICE/flush in relation to the fender, if my math is correct and my assumptions of fitment are right...


Good thing about those images is that they help to illustrate Wheel Spacers if you understand the math for wheel spacers...that would be a cool piece to add in some of the diagrams

Good Stuff!

Thanks for the responses. Again let me say that this is a VERY VERY generalized overview of learning offsets. It doesn't go into detail about wheel lip and flushness. The lip of a wheel takes one more extra step to figure out. Notice some of the pics that were posted above? The spokes (face) of the wheel has a certain size also. You need to take that into calculation to figure out flushness....

Next thing we could do is a chart on what clears coilovers and what doesn't.

Width---------------------Offset

6.5 Inch------------------ ????
7 Inch-------------------- ????
7.5 Inch------------------ ????
8 Inch-------------------- ????
8.5 Inch------------------ ????
9 Inch-------------------- ????
9.5 Inch------------------ ????
10 Inch------------------- ????
10.5 Inch----------------- ????

^^ If we can get something like that filled in, that would be the best guide to buying wheels. Again remember, its easy to figure out what will clear coilovers or clear a wheel hitting your chassis. BUT it wont necessary mean the wheel will be flush or be sticking out too much.

THE FRONT (Lip part) OF THE WHEEL IS CALCULATED DIFFERENTLY FROM THE BACK

I don't get how offset is such a hard thing to understand

6"+54 or lower
6.5"+45 or lower
7"+40 or lower
7.5"+34 or lower
8"+30 or lower
8.5"+24 or lower
9"+20 or lower

front wheels only, rears should have more clearance for coilovers.

Don't you mean left?

baller should be stickied even though its been covered 1 billion times

just to let you know, a 17x10 wheel is not 254mm wide so centerline is not 127mm.

you need overall width for centerline and offset measuring, which in the case of a 10" wheel will probably be 11".

and there's no reason to convert to mm until after you subtract centerline from backspace, which would give you the offset. it's pointless to convert backspace, overall width and centerline to mm since most people here are in the US and use inches to measure unless they are just trying to be jdm.

any chance we could get this stickied? this is truly helpful for us noobs.

case point and said.
a 10" wide wheel is not 10" physically.

roughly 11" yes.

i measured a 9" wheel, hair under 10".

we all know americans seldom use mm.
so heres a inch table:
http://img338.imageshack.us/img338/8...loffsetue7.gif
if you cant resourcefully use this^
i laff.

no my good man, i have no life.

For those that don't understand english too well (Esedy clutch lol), hope these pics clear up any doubts.:bigok:

http://i64.photobucket.com/albums/h1...fset101new.jpg

:bigok:
Thank you for the wonderful picture:bigok: , hahaha classic

oh your an asshole! LOL good job though.....:keke:

NIce thread Sil40sx. I could had done a better thread but oh well. LOL

If your in the wheel business then it is 10" you dont messure a wheel from end to end, you mesure from the seat to seat.
We always use mm... cus engineers and designers never us anything US.. hehe ... only the metric system. This way its the same world wide.

... these are some nice pics you guys are coming up with....
I will use the hell out of these for trainging..

but the point is when you are figuring out offset you do NOT use seat to seat width, you use overall width. if people tried to figure out the offset of their wheels using what people said earlier in the thread it would be wrong. when a wheel size is not marked most sellers of wheels in the US and some in japan (upgarage) do not correctly measure the wheels and you end up with a different offset and width.

and they were talking about converting to mm which is 100% pointless except for offset, not actually measuring in mm. this thread is not about engineers and their fancy metric measuring tools, it's about retarded people on zilvia trying to figure out what size their wheels are.

Great write up!

Definitely needs to be stickied

This is true, I always just add 12mm to the side im trying to get a tight fitment on. I t would be nice if the width was taken from lip to lip tho.... If someone need to get detailed you would need to messure the wheel by hand.

That is completely irrelevant to this topic.
OP isnt in the wheel business.
You'll HAVE to measure the physical dimensions from lip to lip because ultimately, the seat width doesnt matter for shit when you're fitting the wheels on the car.

Doluck, you're a jackass

we're not talking about how to measure a wheel

we're talking about how to measure the offset of a wheel which is not obtained using the seat width.

Wow ... you guys are tards.... If you read the whole post you woudl see the relevants.

If you have a 10" wide wheel(254mm) with +35mm offset.(254/2+35=162)(254-162=92) so you cant go thinking that you have 162mm / 92mm, cuz when we tell you specs on a wheel its width is from seat to seat. That 10" wide wheel is really 10.8" or so. You back space is really about 102mm not that 92 you would get from that wheels specs. get it... it was just an fyi. So chill out...

hence our response:
10" wheel is not physically 10", rather nearly 11".

you just reiterated what we said.

But the offset is that of a 10" wheel. which means you need to add a few mm to you math if you are doing the math for a perfect fit.

how can you tell the offset from looking at the back of the wheel? what letters are typically used to determin it.

if the wheels are worth a flying fuck there will be a stamping or a sticker showing the size, width, manufacturer, offset, model number etc...

No its not right... thats what im trying to tell you. if the maker says its a 10" wheel its not, and they say the offset is +35 well its not. Cuz the wheel is really 10.8" and the offset (from lip to lip) would change. The offset # we give is off the width from seat to seat.

http://img338.imageshack.us/img338/8...loffsetue7.gif

posted that earlier.
you must've missed it.

but i see what you're saying.

my work vs-ss and work emitz have the sizes stamped on them, the ssr d5r's have a sticker.
my amistad type d, no sticker or marking. my old weds kranze cerberus, no sticker or marking. i guess they are not worth a flying fuck then. :(

that is completely wrong. backspace - centerline (based on overall width of course) = offset. i've measured wheels with marked sizes (rota grid off road, work emitz) and my measurements match what is on the wheel. rota said +10, it was +10, work said +0 and -16, it was +0 and -16.

^ thats wierd

my weds kranze cerberus have stickers


guess yours fell off

I do know Rota do give you the total width.. I found that out when I worked with them awhile ago. Thats why they are one of the brands I carry.
My works, volks,enkei and 99% of the other wheels I have sold have never added up. Rota does it to cut down on weight.

Wow. You should read the "for all you rota haters" thread haha

I did... I know 240 guys dont like them... I love them, but that cuz I can sell the hell out of them to honda guys..

where do i look?

http://img137.imageshack.us/img137/3448/p1020244tk3.jpg
http://img521.imageshack.us/img521/7286/p1020257fy3.jpg
http://img521.imageshack.us/img521/4522/p1020258yd8.jpg

I would IMAGINE the k-50

My Konig Rewinds had the -9 on the inside in a similar area, my Volks had them on the back also(+42)...So do my BBSs(+0, +19)...thats the only number I could see being it...what is the style of the wheel?

they're enkei sporsh

http://img137.imageshack.us/img137/8872/p1020249qh7.jpg

like the pic in post 26! def helps to understand. might show this to a few ppl.

any advice? it appears to have a positive offset, but of what? is the question.

So noobie question
What are the pros n cons of having plus or minus offset is it just for looks
or do certian wheels have certian offsets to fit correctly

Making this a sticky

Keep it clean.

To insulting users, consider being warned.

In a nutshell:
And as for what "scrub radius" is:
Also, lower offset = harder on wheel bearings, so that's something to account for.

Is there any other stickers on it?
usually there is a sticker with the size, and next to a a positive or negative number followed by a number(*in smaller letters)
if not then you would need to get it measured,
or check the manufacturers website to see the different offsets they offer and try to guestimate which one you have!

Wheel fitment with coilovers....
 

Hope you guys dont mind me asking a question here rather then starting a new post. I picked up a set of wheels and some coilovers, there not installed yet. I still have to convert to 5 lug. My question is, would I need front spacers if running a 18x8.5 with a +30 off set when using coilovers? If it matters, Im going to be using Rays Gramlights 57F's with Tein Flex coilovers. Rear wheels will be 18x9.5 +20 off set.Thanks...

16x7 +50
Most oem wheels are stamped like this.
The offset will be a random spot on either the back of the face, or the front near the bolt holes.

http://i25.photobucket.com/albums/c70/MrChow/Offset.jpg
There... Look. 16x7 +51
There all normally posted somewhere just like Yuri said.

dam +51. Teardrops are less than that.

lol ..... here play with this http://www.rims-n-tires.com/info_specs.jsp
.
.
.
.

this is an example of my rear setup im currently using:
Volk CE28N
18x9.5 +28 offset
265/35/18
negative 2deg camber

http://img.photobucket.com/albums/v2...MG_0219_sm.jpg

This rim resembles the 1st illustration on the left showing positive offset. Since the illustrations below are exaggerated a bit to show the differences, it has a curb appearance of the center illustration even tho my rear setup is positive.

http://i64.photobucket.com/albums/h1...fset101new.jpg

These are pics from the back of the rim showing coilover to rim clearance. The clearance between the rim and coilover is about 30mm total. (be sure to leave at least 4mm open space for things to move, otherwise you will rub)

http://img.photobucket.com/albums/v2...MG_0234_sm.jpg

http://img.photobucket.com/albums/v2...MG_0222_sm.jpg

this is how the rear looks with this setup. with minor lip massaging and -2deg. camber adjustment, the wheel tucks without major rubbing.

http://img.photobucket.com/albums/v2...x/dc_92_lo.jpg
http://img.photobucket.com/albums/v2...40sx/dc_91.jpg

Do you have pic of clearance in the front???


Very nice post btw :)

Nice, but it doesn't allow for stretched tires

great thread for people who don't understand offset and wheel fitment. hopefully everyone on zilvia will now have wheels that sit flush.

great explaination. all of them

Does anyone know if a +38 offset is a good offset?

^^ Uh??

It isn't? That's high. Go to the fittment thread.

^Just curious thats all.

:ugh:
It's a pretty good one. The curves of the three echo those of the eight, but the incomplete circles of which it is compose draw the eye to the contrasting right angles of the 'plus' sign, traditionally associated with positive feelings.

or you could search

Oh lol. stock offset is around 40 ish +. Does that help?

I think it'd be alot more useful if we can find out what kind of backspacing clearance we have with STOCK wheels on S13 and S14.

then you can just plug your sizing into a offset calculator on that miata webpage and find it out from there on.

obviously, stock struts and coilovers have different clearances and its all different for every different coilover.

Providing a base of what the clearance would be with ALL stock parts would basically lay a foundation for others to build on, though.

Unfortunately, I dont have any of these informations.

i guess i can learn something new everyday. its simple

wow, looks like it's gone abit lower or negative than 101

good offset calc. find philvia, I would've never gone further than tirerack or some shit of the same! lol. I just study the books and common knowledge. + I have my wheels. haha.


But, ahem. to keep to the current trend subject. I feel it depends on the complete system of the wheel to determine whether the +38 offset is good for a car, let alone FR, if being placed in the
rear?

I could hear these numbers being thrown around the pits of WRC or SCCA rally.

wow that was so easy to understand even a cave man can do it now. lol

sorry i just want someone to tell me yes or no
 

18x10.5 with -7
for front with vertex fenders
18x12 0 offset with vertex rear 35mm fenders

will these fit ???

s14 chassis

^^HAHA I was gonna say the same thing. I was trying to get it to do a 225 on a 10 for like 45secs, but it only would do a 255.
FAIL.

FN01RC's
 

I have a 90 240sx and i want some fn01rc's preferably 17x9 that have a deep dish look what offset do you guys recommend and will these clear a 300zx brake set up and coilovers without them sticking out if not what do i need any opinions or recommendations are appreciated
thank you

fn's don't have dish...

It might be tight on the inner clearence for the front, what size front over fender? Also what brakes. The rears your going to have to MAKE work with proper camber and tire size.

Thanks for sharing this info. It was clear enough for an old fart like me:)

Every Nice!!! Thanks. ^_^

Very nice guide. I had no idea about offset before reading this thread. Now all I have to do is study up on camber and tire sizes and then I'll truly grasp the idea of wheel fitment.

Not quite.........
When a rim is said to be 10" or 7" wide, that is the width where the tire sets.
Actuall rim width is usually about 1" wider because of the lip thickness.
(aprox. 1/2" per lip)

So a 10" rim is actally 11" wide on the outside.
And this 1/2" will sometimes cause clearance problems with shock bodies, tires, etc..

if there is someone who still cant understand this simple examples... ill hit him in the head.

For the life of me I can never keep straight which direction is positive or negative when dealing with offset.

Sorry guys I couldnt find pics or info with anyone running a setup similar to what I am considering for my stock bodied s13 w/coilovers so I figure I just ask for help. The wheels I am considering are 18x9.5 and 18x10.5 with a -10 offset for all.I am assuming I am going to have to do some pulling/rolling but how much? I tried digging up pics but no luck if anyone can find any that would be great. Thanks guys!

can anyone just tell me what width of rims do i need for them not to rub anything with 0 offset and them being as close as possible on both sides i dont want them sticking out i want them under the fenders their 18'' and on an s13

Good Thread
 

Very understandable. But i'm addicted to negative offset. Very good thread.

BEST POST EVER! This post makes it easier to explain to people what and how offset works. Now I dont even have to talk to them, I just link them here. +1 to you