rim help

[shane-xlt]

hey everyone im looking at these rims.

http://www.1010tires.com/Wheels/TSW/Vortex/Chrome/Chrome

The tire size im looking at is 255/50 20 that would keep my speedo right.

im just wondering about the offset, would it work or would i need some spacers?

 

[Sp0rtTr4c]

I would think they would work since they are 20's they might clear the spindles, but you will want spacers with an offset that high or they will be no where near flush with fenders. You will narrow your track which will result in poor handling and looks.

 

[shane-xlt]

ok so if i got the ones with the 20x8.5 with 40mm offset how much of a spacer will i need? I also will be lowering the truck. If that makes any difference.

 

[shane-xlt]

anyone?

 

[05dakotatrac]

honestly going off the common wheel swap of 15X 8 cragar soft 8's with 4" backspace leaves an offset of 0" or close to it. this gives a little extra wide stance but within factory settings.

for 20"X 8.5" inches a 3.5" or 3.75" backspace would be perfect for your setup it would keep a more fender flushed look. as for offset that leaves an offset of .75"

 

[shane-xlt]

so your saying a 3.5" or 3.75" spacer is what i would need?

 

[OffTrac]

A 20x8.5 with 40mm offset is a little over 6" backspacing if my mental math is correct (could be way wrong, sorry, no guarantees). A 2" spacer would put you about where you want to be.

I think. The wheel thing is kinda confusing but anyone is welcome to check my math. I've never been wrong in my life before, though, so it's pretty safe to spend big money on the advice of a stranger on a forum.

 

[shane-xlt]

lol what is the stock offset. i have a 2005 xlt with stock 16's

 

[OffTrac]

Not sure but it's whatever 1" converts to in mm...I think.

The stock rim is 7" wide. 0 offset would be at 3.5". Stock backspacing is 4.5", so the offset would be the difference between the backspacing at its center point (0 mm offset). So, whatever 1" is in mm is what the offset would be.

 

[05dakotatrac]

i was referring to back space which refers to the distance from the back (inside) wheel to where the mating surface is (the part that touches the brake rotor). stock wheel is 16"X7" with a 4.5" backspace meaning the offset is +1". now take that same stock backspace on what you are looking at 8.5" wide rim divided by 2 equals 4.25" for the center line with the stock backspace that gives an offset of +.25". rule of thumb is the wider the rim the less offset you want (offset can go into the negatives as well) and the higher backspace you need. if you go wider rim and never change backspace then the extra width is put inside the wheel well which results in rub at full lock.

40mm = 1.574"

for that width of rim to keep the factory spec. of 4.5" of backspace you need an offset of closer to 6mm or 5mm