billytoad631

im gettin either crager soft 8's or street lock D in 15x8 im gonna be running 32's with cut fenders but im really not sure what offset/backspacing i should get

help?

askingxforxit

Probably a 4" bs

billytoad631

what about offset? there was a set with -13mm offset and one with 6mm offset, i dont really know what offset is. but i understand how the backspacing works

askingxforxit

This might help

http://www.tirerack.com/wheels/tech/...jsp?techid=101

billytoad631

i get it now, kinda. the lift i have recomends 3.75 bs so im probally going to get that instead of 4 bs, but i still dont know what offset to pick. should i just get 0 offset?

Driver X

-19 is 3.75" backspacing. -12 or -13 is 4" I believe and -6 is 4.5"...
My 15x8s had 3.75" backspacing and the box said -19 offset


Back Space to offset conversion:
Take overall rim width including outer lip (usually listed rim width + 1"), then divide by 2, then subtract that number from the measured backspace, then convert that number to metric by multiplying by 25.4.

so: 15x8 inch wheel with 5.5 inch BS
8"+1" = 9" /2 = 4.5"; 5.5" - 4.5" = 1" *25.4= 25.4 offset

Offset to Backspace conversion:
Take offset, divide by 25.4, then add the overall rim width divided by 2

so: 15x8 with -19 mm offset
-19mm / 25.4 = -.75" + (((8"+1")/2)= 4.5") = 3.75" BS