Wheel Offsets

[Ketron10a]

Ok need soem help understanding wheel offsets. Internet explanations i find provide bad explanations for me and really need laymans terms. I know for a fact my buddy is running some Diamo 18's on his 05 f250 with no lift or suspension mods....but it says this wheel has a 10mm offset. The tire dealer told me I couldnt run these wheels because off sets are made for lifted trucks but provided no explantion as to what happens when u stick it on a stock height truck. So....anywaone care to enlighten me as to what an offset is and why its important?

next....what backspacing should I be looking for on an 04 ex to move up to an 18 or 20 in rim? not really looking to lift....plan on doing v/b spring install.

Also whats the deal with hub centric? Most wheels I find are not hub centric so what gives?

[Chillinthemost]

Backspacing is the measurment from the mounting flange of the wheel to the innermost part of the wheel. A wheel with 4in. of backspacing would stick out from the truck more than a wheel with 6in. of backspacing. On an Excursion or 04 or later Ford you need less than 5in. or when turned full lock the tires will rub the leaf springs. 05 and newer coil spring trucks can run up to 6in. of backspacing.
You wont hardly find any aftermarket wheels that will be hubcentric. It is a better and stronger way of mounting but I and thousands of others have 0 problems with lugcentric wheels.
Hubcentric (factory wheels are hubcentric) center themselves on the axle or rotor hub and fit snug on the hub. The lugs only hold the wheel to the truck, the lugs usually have a washer built into them and only clamp. Lugcentric wheels use the tapered lugs to center up and clamp the wheel to the truck. They are considered wealker because the wheel studs carry the weight. I cant imagine 8 14mm studs all breaking, it would take a tremendous amount of load.

[HeavyAssault]

Greg Weld Design, USA Forged by American Eagle Wheels , Alcoa wheels, older Weld Racing wheels are all hubcentric design. Weld offers a better selection of designs but they I think they have stopped production of truck wheels.

[Ketron10a]

OK Had an already good understanding of backspacing. Just needed to know what the Excursion backspacing should be. What I dont understand is wheel offset. Usually described as a positive or negative number in millimeters?

[panteramatt]

I want to know about offset also.

[Ketron10a]

Another Bump?

[Trigger]

Offset is the distance between the centerline of the wheel to the mounting surface.

Look here for more information. I think this will answer a bunch of questions.