What front offset for custom wheels on 86 Carrera?
 

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
http://members.rennlist.com/1976c38/...AQ-diagram.gif

what width and is it front or rear

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.

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

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

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

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

all of the above include the lip

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

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



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



true

true

many wheel manufacturers, perhaps most do include the lip

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