What front offset for custom wheels on 86 Carrera?

[Ho Hum 74]

I'm trying to get a replacement custom wheel for a 1986 Carrera. The wheel is a 17" Kodiak. The OEM has no idea what size to make the wheel to and has no record of my purchase. I have measured the back spacing as 137mm from the face of the wheel hub to the outside rim of the wheel. There is about a 9mm lip which makes the backspacing 128mm.

Does this sound correct? Anyone, please help.

Thanks
Tristan

[Bill Verburg]

Originally Posted by Ho Hum 74

I'm trying to get a replacement custom wheel for a 1986 Carrera. The wheel is a 17" Kodiak. The OEM has no idea what size to make the wheel to and has no record of my purchase. I have measured the back spacing as 137mm from the face of the wheel hub to the outside rim of the wheel. There is about a 9mm lip which makes the backspacing 128mm.

Does this sound correct? Anyone, please help.

Thanks
Tristan

No
backspace includes the lip


what width and is it front or rear

[PcarPhil]

I just recently measured the backspace of my 9x16 Fuchs that I'm using on the front of my widebody conversion and it measured 138mm.

Disregarding the widebody aspect of my car and focusing on the backspace then yes your first number (137mm) sounds absolutely correct to me.

Edit: I'm saying the same thing that Bill is saying. Your 137mm measurement is the backspace.

[Ho Hum 74]

Bill,

I agree, and in your picture it is measured that way. Just Kodiak's measurement is to subtract the lip...don't ask me why.

This is a front wheel and it is an 8" front width.

Thanks for your help.

Tristan

[dickepoohp]

I understand the backspace...what would/should the offset be?

[Jeff Alton]

accoridng the tire and wheel guide width and backspace do not include the lip....

I replied to your email, we will get one built based on the measurements you sent me and confirmation with the build sheets from the folks you got the wheel from originally.

Cheers

[Bill Verburg]

Kinesis 8 ET25 has ~139mm bs
Fuchs 8 ET23.3 has ~132.5
Fikse 8 ET31.3 has ~145.7

[Bill Verburg]

all of the above include the lip

[Jeff Alton]

Offset is the number that counts. lip has nothing to do with where the tire sits. There is variance with the lip from manufacturer to manufacturer and from run to run of product from a single manufacturer.

Using the lip though makes it very easy for anyone to measure.

The width of the wheel does not include the lip either.

Cheers

[Bill Verburg]

Originally Posted by Jeff Alton

Offset is the number that counts.

true, all you need to know is the width and ET

Originally Posted by Jeff Alton

lip has nothing to do with where the tire sits.

true, but it does extend the space needed to clear various things like suspension components

Originally Posted by Jeff Alton

There is variance with the lip from manufacturer to manufacturer and from run to run of product from a single manufacturer.

true

Originally Posted by Jeff Alton

The width of the wheel does not include the lip either.

Cheers

true

Originally Posted by Jeff Alton

wheel guide width and backspace do not include the lip....

Cheers

many wheel manufacturers, perhaps most do include the lip

[Jeff Alton]

All true!

I actually just ordered an updated "tire and rim guide" to make sure I am up to date.

The lip varies quite a bit depending on the construction method. A one piece wheel typically has a smaller lip that a wheel with a spin formed wheel half. A fuchs 7 inch wheel is around 7.6 inches in total width (lip to lip) while a typical 3 piece wheel is around 8 inches lip to lip. In both cases the centerline and sidewalls of the tire are in the relative location to the vehicle, depsite having different "backspace" measurements. (assuming the same offset)

I know you know this Bill, but felt it may be good info for others who are interested.

Cheers