Rim offset help?

[bruni911]

Hi i currently have a 19" by 10" rim with a 62mm offset, i am going to a 19" by10.5 rim with a 45mm offset, how much spacer will i need.. 17mm? thats what i a am guessing? Thank for your help.

[DougM]

Actually the opposite. Less offset means more "lip". The less offset will push your wheel 17mm more out and the extra 1/2" width add an additional 1/4" or 6.5mm to that (1/2" will add 1/4" to both sides of the offset). You will be pushing your rim almost 1"(@26mm) more toward your fender lip.

----I---- "0" offset absolute center of the rim with equal frontspace and backspace
---I----- "-" offset mounting point toward inside of rim with less backspace and more frontspace (larger lip)
-----I--- "+" offset Mounting point toward outside of rim with more backspace and less "lip"

[bruni911]

Thanks doug, so right now i have a 2" spacer, so i would have to machine it down one inch? how can i find out the exact measurement, Thanks again.

[DougM]

1"=25.4mm
Your offset difference pushes the rim out 17mm
The extra 1/2" width adds @6.5mm more to that inside and out.
The new rim will have 23.5mm more "lip", just shy of 1"
You may have some extra space under there to accommodate the offset, but with a 1" you will push your rim 2mm inward.

[bruni911]

Thanks for you help Doug, i finally understand it..