Wheel Offset - How to Measure?

[Duffman]

Probably a dumb question, but I have a set of aluminum wheels I am selling and want to confirm if there is any offset on them. Is there something stamped on the wheel to tell, or is there a way to measure it?

Thanks!

[240ZX]

Wheel offset.......half way between the outer/inner bead of the wheel would be "0" offset. If the mounting flange is inboard of the center you'll have positive offset and if the mounting flange is outboard of the center you'll have negative offset. Now its just a matter of measuring! Hope this helps you to understand wheel offset.

Tom

[Arne]

Stephen, measure the overall width at the outer lips. (This is typically about one inch larger than the true rim width at the bead seats.) Divide this number in half and save it. Then set the wheel face down on the floor. Place a straightedge across the back of the wheel. Measure from the straightedge to the mounting flange surface, where the wheel sits against the drum. (This measurement is also known as 'backside'.) Subtract the first saved measurement from the face-down number. The result is the offset.

If the numbers are equal, that's zero offset. If your end result is a negative number (your backside is smaller than half the width), that is negative offset, which gives deeper dish. If the backside is larger than half the width, it's positive offset, which tucks the wheel inside the fender farther.

In the case of the 14x7 Appliance Wire Mags you have for sale, Here's what I expect you will find (approximately):

Overall width === 8.00"

Half of overall = 4.00"

Backside ======== 3.62"

Offset ========= -0.38"

That'll be the same as a -10mm or -3/8" offset. Similar to a 14" Konig Rewind.

Of course, I could be wrong since I'm going from 15-20 year old memory here, and I'm very interested is hearing your measured results on these wheels.

[Duffman]

Thanks, Arne and Tom, appreciate the quick responses.

Will let you know what I come up with, Arne.

[Duffman]

Arne, you are right on, it measures out to -10 mm or -3/8" offset. Should have just used your measurements and saved myself the effort!

[Arne]

That's what I recalled for those older Appliance wheels. Both the Wire Mag (like yours) and the Dish Mag (slots) in 14x7 came with a relatively deep negative offset. (Not surprising, they were originally designed to fit 4-lug Mustangs and such, not import cars.) We ran into occasional rubbing issues with those on the front of 240Zs back in the day. Weren't no modern low profile tires back then to compensate.