How to calculate offset from backspace.



[(backspace) - (rim width divided by 2)] x 25.4 = offset?



please see attached file... Found some Cobra R 17x8 wheels. I know stock mustang GT wheels are +30 offset. But according to this summit racing advertisment, the backspace is 5.72. Which means it's 43 mm?



clarify?

 

they're definitely 43mm offset if that's what you're asking.



Mark

 

I like those wheels too. Not too expensive. But they frigging weigh 25 lbs!!!! That is baloney slicer territory

 

I reckon superleggeras are still the best weight to cost wheels around.



Mark

 

you did not include rim lip in your formula, that is not part of the wheel width. 8 inch wheel is actualy wider then 8 inches that is why it doesnt work. here is how to do it.



http://www.rsracing.com/tech-wheel.html#backspace

 

If you take into account 1/2" lips on each side (which seems about right to me) you come up with a 30mm offset. You learn something new every day.



Mark

 

ah!!! that makes sense now