Ok. I want to put some Mickey Thompson Baja Claws that are 38.5x16x16 on and I need to know what amount of backspacing I am gonna need? I already have 16x10 with 4.?? and my tires are BFG 315/75/16=35x12.50-16 how much more backspace do i need? thanks! James

You have upgraded UCA's yet?

no. i am awaiting word back from another TS member about buying them from him for cheap...later!

It's not just the backspacing that will get you, it's the width. You're going to need the aftermarket UCAs for the space they provide.

(btw that's not me you're waiting on, is it? Just the lowers?)

With 4.5" backspacing, you can fit 2" of section width inboard of the wheel...so 12" section width on 16x8 with 4.5" backspacing (BFG AT/KO 315/75/16 on 16x8 has 12" width, not 12.8).

Find out exactly how wide those 38.5x16 tires really are, subtract four, and you need a wheel at least that wide with 4.5" or 4-5/8" backspacing.

It will be tight to the frame, it will stick out farther, and you're asking for busted axles unless you're gentle with the skinny pedal...but it can be done according to Arctic Trucks.

You're probably looking for 16x12@4.5" backspacing, hopefully width on that tire is something like 15.7 not 16.8.

Also ask how much the section width will change if you change rim width. Usually it's about 0.2" per 1/2" of rim width but on a tire that large I don't know if the relationship holds.

-Sean

It's not just the backspacing that will get you, it's the width. You're going to need the aftermarket UCAs for the space they provide.

(btw that's not me you're waiting on, is it? Just the lowers?)

With 4.5" backspacing, you can fit 2" of section width inboard of the wheel...so 12" section width on 16x8 with 4.5" backspacing (BFG AT/KO 315/75/16 on 16x8 has 12" width, not 12.8).

Find out exactly how wide those 38.5x16 tires really are, subtract four, and you need a wheel at least that wide with 4.5" or 4-5/8" backspacing.

It will be tight to the frame, it will stick out farther, and you're asking for busted axles unless you're gentle with the skinny pedal...but it can be done according to Arctic Trucks.

You're probably looking for 16x12@4.5" backspacing, hopefully width on that tire is something like 15.7 not 16.8.

Also ask how much the section width will change if you change rim width. Usually it's about 0.2" per 1/2" of rim width but on a tire that large I don't know if the relationship holds.

-Sean


OK. Here is pic of the tires I bought. I paid $280 for all 4 off of eBay.
http://i6.ebayimg.com/01/i/000/d5/87/bb63_1.JPG

http://i8.ebayimg.com/01/i/000/d5/87/cbe8_1.JPG

prepair to cough up a WAD of cash when you go to replace those.......not to mention I bet you will have some serious steering issues....

HEY, please ask the guy balancing the tires for the numbers before and after. See if you can beat my old BFG's, they were almost 18 oz. ooff on all four corners.

haha ok