Help with aftermarket rims......

[lorenambrose]

From the wheel article in the tech section, I see that a 15" wheel should have a backspace of 3.75 in. giving it a -19mm offset. However when I look at different wheel manufacturers the sane 15x8 wheel whit a 3.75" backspace has a wide range of offset numbers. If I am understanding this right, offset is in reality the same measurement but expressed metrically. I could be wrong though. Can someone explain this to me?

Also the 7 and 8 inch wide rims have the same 3.75" recommended backspace. This would push the rim out 1" if using the 8 instead of the 7. How can the backspace be the same for both wheels? What is the real recommended backspace for a 15x8 wheel for a 2003 Ranger Edge.

 

[jdm_farmboy]

Backspacing and offset are measured by different locations. Backspace is the distance from the axle pad to the inside bead seat. Offset is the distance from the centerline of the wheel to the axle pad.


The 15x8 and the 15x7 have the same backspace but they will have a different offset numbers.

I'm not sure why the same size wheels with the same backspacing would have different offsets.

http://www.therangerstation.com/tech_library/wheel_fitment.html

 

[lorenambrose]

that is what I am wondering. Also why would a 8" rim have the same recommended backspace as a 7" rim.

 

[Original_Ranger84]

Well it would fit better, if you went to an 8 " rim but the backspacing also increased an inch then the rim would sit farther back and most likely cause something to rub. So a 15x8 with a 3.75 backspacing should be fine... thats what I am running right now.

I stole this from another thread here, but it explains the offset and back spacing and why/how they are different. https://www.rsracing.com/tech-wheel.html#patterns

 

[Jay FX4]

Hey, that link looks familiar....

 

[Original_Ranger84]

Hey, that link looks familiar....

I stole it... i mean borrowed it for the greater good.

 

[jdm_farmboy]

Also why would a 8" rim have the same recommended backspace as a 7" rim.

The 8" and 7" rims have the same backspace because it will place the inside lip of the wheel in the same location based on the hub.