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..