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Old 12-13-2012, 02:43 PM
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Default Re: What Offset For 20" Wheels / 14" Tires

IMO it's easier to think about it from a strictly 'backspacing' point of view. Everyone on this site seems to be worried about what 'offset' their rims have, but offset really doesn't tell you much by itself. You still need to know the width of the rim to determine how much of the rim will be under the truck and close to the suspension to determine if you'll get rub. They're using offset and width to calculate 'backspacing,' so why not just talk 'backspacing' from the get-go? LOL!

I found that with the stock rims which are 8 1/2" wide and have a 5 5/8" backspacing (in other words, 5 5/8" of the rim go inward toward the suspension and the remaining 2 7/8" go outward from the hub) my 37x12.5 BFG MTs rubbed in both directions at full lock. When I went to the Rockstars (9" rim) which have a shallower 4 1/2" backspacing I had about an inch less rim/tire going in toward the suspension, so the same tires exhibited no rubbing. This also gave the truck a more aggressive look since it pushed the tires outward about an inch and a half as well.

When trying to figure out what's gonna cause rubbing...it just makes more sense to me to look for the 'backspacing' first...'cause that tells you exactly how much rim/tire is going 'back' toward the suspension. I only look up the 'offset' if the backspacing isn't published.

For 14" tires I'd think you'd need to get an even shallower BS if possible. 'Cause if 4 1/2" BS makes my 12.5s not rub, adding another 1 1/2" to the overall width will put another 3/4" of rubber back toward the suspension. I don't know how much clearance I have at this point, but I'd think you want to at least try to push the tires out another 1/2" to make up for the additional rubber...which would put you at a rim with a 4" BS...3 3/4" would be ideal, but I don't know that I've seen rims wide enough to run 14s with that shallow of a BS. 14s seem pretty damn wide for a leveled truck...I'll see if I can get pwrhse2k to chime in. I think he was running tires close to your size on his truck when it was leveled.
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Last edited by guruerror : 12-13-2012 at 03:05 PM.
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