[hwntime]

Anyone know which is a better backspacing fit for the F22? Same dimensions on the wheel but two different backspacing measurements. Does the backspacing measurement affect the concavity of the wheel?

18x8 5x120 +42mm - 5.760 backspacing
18x8 5x120 +42mm - 6.150 backspacing

[dradernh]

Originally Posted by hwntime

Anyone know which is a better backspacing fit for the F22? Same dimensions on the wheel but two different backspacing measurements. Does the backspacing measurement affect the concavity of the wheel?

18x8 5x120 +42mm - 5.760 backspacing
18x8 5x120 +42mm - 6.150 backspacing

My understanding is that if the wheel widths are equal, and the offsets are equal, then the backspacing will be equal. In your example they are not, and I wonder why.

That said, I have been known to get more than a little confused when so far down in the weeds with this stuff, so please take my opinion with a large grain of salt.

You may find this page useful:

https://www.rsracing.com/TechWheel.aspx

[hwntime]

Originally Posted by dradernh

My understanding is that if the wheel widths are equal, and the offsets are equal, then the backspacing will be equal. In your example they are not, and I wonder why.

That said, I have been known to get more than a little confused when so far down in the weeds with this stuff, so please take my opinion with a large grain of salt.

You may find this page useful:

https://www.rsracing.com/TechWheel.aspx

That's what I thought, that if offset is equal on two wheels with the same dimensions, then backspacing would be the same? This threw me off and that's why I'm asking if anyone here has any idea.

[aerobod]

Backspacing is measured from the inside rim lip/flange to the mounting surface, so a different lip profile can give different backspacing readings. A “J” profile flange should be the same profile from wheel to wheel, but there is some variation from what I have seen. Offset (ET) is a much more consistent measurement to compare between wheels.