18" wheel back spacing?
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18" wheel back spacing?
okay so im putting 18" wheels on my truck. (i have a brand new set of 35x12.5x18 tires) so i need to know what would the best back spacing be for the wheels. i have a rough country 4" lift on my 94 bronco. the paper in the kit said 3.75 back spacing. would i still use that even though its an 18" wheel?
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From: Gateway to the West
Diameter is only one dimension of the wheel in question. Can we assume a proper rim width of 10" for these 18" behemoths? If so, then a 35 is going to just barely make it under most 92+ models. You may still get some rub on radius arms at full steering lock. 35's fit best with a little more lift typically. But I know many folks who have gotten away with them on 4" of lift. The recommendation for 35's for unfettered operation at full articulation is 6" of lift in 92+ models.
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18x9 actually. i know i'll need to trim the front bumper and thats fine with me. i've been playing with the idea of newer ford cut out fender flairs. i dont like the ones for my body style. i loke the ones with the pocket style. i've got some rust so i can kill two birds with one stone with cut out flairs.
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From: Gateway to the West
I will caution you that no tire manufacturer will guarantee their tires mounted on a rim 3.5" narrower than the tire section width. If that and the extreme additional strain on the bead is not a concern for you then go for it. Personally, I wouldn't mount those tires on those rims. Bead failure especially at on-road tire pressure is rather likely in that situation.
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huh, i've got those size on my f250 right now. had them on for a year and a half. hell had over 5Klbs in the bed...granted it wasnt supposed to but it handled it just fine. i only went a couple miles at about 20mph tho. then had 3K lbs in the bed for 50 miles at 70mph and had no issues at all with them. i figured my tire guy would have said something about the width issues...
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From: Gateway to the West
I can only go by what the tire manufacturers list in their documentation. I won't say its wrong, I just say it is a tight fit to have a full 1.75" (nearly 2") of section width OUTSIDE the support of the wheel on each side of the tire... that would be MOST of the sidewall and probably even a little bit of the tread width that is unsupported by a 9" wheel with a 12.5 section width tire. Its just the math the tire makers use... 12.5" - 9" = 3.5" wider than the rim. 3.5 / 2 = 1.75" hanging out beyond the support of the rim on both the inboard and outboard sides of the wheel. Some folks run that way all the time... just be careful if you end up needing tire warranty service. I know BFGoodrich, Bridgestone, Goodyear, and several others have the 2.5" difference between wheel and section width limit in the wording of their warranties. It is considered undue bead stress and constitutes misuse under the terms of the warranty.
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interesting, however isnt a 12.5" wide tire really only like 11.8 at the tread? i run nitto's on my truck and on my mustang. the stang has a 295/35/18 on a 18x10 rim. so thats a bit better...lol
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Lead Driver
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From: Gateway to the West
Has nothing to do with tread width. Section width is the key because it is the entire supporting structure of the tire not just the part that grabs the road. The sidewalls do more to support the weight of the truck than the tread does anyway.
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right i understand that the side wall is the load bearing part of the tire. its just almost impossible to find an 18x10 rim. mickey t has the classic lock, but the classic II is 18x9. most of the 18's i've found are all 18x9 or 18x8.5's im just surpised that they are making more 9" wide rims than 10's being that you wont find a 35x11.5x18 or even a 33x11.5...im not going to say the dont exist. every web site and ad im a magazine all have a good selection of 18" tires and wheels but i've been hard pressed to find more than one or two out of hundreds that are 10" wide. like i said i would have never given this any thought at all, untill you mentioned something. its just odd to me...lol
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From: Ottawa, Ontario
okay so im putting 18" wheels on my truck. (i have a brand new set of 35x12.5x18 tires) so i need to know what would the best back spacing be for the wheels. i have a rough country 4" lift on my 94 bronco. the paper in the kit said 3.75 back spacing. would i still use that even though its an 18" wheel?
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