Fitment Sanity Check

[Betelgeuse]

Can someone look at the pics I posted and double check my math? I'm using Speedways Tire fitment tool and I came up with +1/4" or +6mm.

[SinisterBuilt]

What where your measurements just so we can make sure where doing the math correctly and not any incorrect info from the pictures?

Generally it would be Wheel Width minus 1”
Then you find the Centerline of that measurement and then you would find the backspace measurement and minus the centerline from that. Sooo In math form

Centerline - Backspace

If you got +1/4 which is 0.250 that would be 6.35 mm

Your tape measure looks like it’s reading 12” wheel width which be 11” wheel so half of 11 is
5.5” take the wheel off and with a square or straight edge layed across the tire measure from the back of the tool where it touches your rotor to the straight edge and that’s your backspace whatever that number is minus your Centerline 5.5” from that. Once you have that number you can do the MM conversion math to find the offset. Hopefully that helps 1” in MM is 25.4

[Betelgeuse]

I set the fitment tool up for a 12" wheel, 13" overall width with outer lips. The tape measure is on the inner lip, so 6" would be centerline and I'm just past the 6" mark. That's how I got +1/4 inch.

[SinisterBuilt]

Yeah if after the math your getting 1/4 then 6mm is right for the offset

[Betelgeuse]

Thanks! Now to try to find some wheels in 18x12 with the correct offset. Probably going to settle with ET Wheels knock off Minilites.