offset help

FordFreak

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I have read some conflicting stuff about wheel offset. I understand backspacing just fine, but offset is confusing. Is a + offset put the rim mounting surface farther away from the truck or closer. I want to get a 16X8 Eagle Alloy 184 Series rim with 4.5 backspacing and a +2mm off set. please help me to understand exactly what this means and would this be a good rim for a 35X12.5X16 trie on an f-150 with a 3" spindle lift. Thanks in advance.

Adam
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cleartoy

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Offset is the opposite of back spacing. Offset is the distance from the lug nuts mounting surface to the outside.

94 Toyota stdcab 2x4
99 Yamaha YZ250

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ntsqd

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The way I undestand it, Offset is the distance from the wheel's centerline to the WMS. So an 8" wide wheel with an Offset of +1" would have 3" of backspacing.

TS

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FABRICATOR

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Wheel terminology (from a manufacturer, edited)

Backside setting/Back spacing - The measurement from the mounting pad to the inner edge of the wheel.

Bead seat - The position where the tire rests and seals on the inside of the rim.

Bolt Circle - The diameter of an imaginary circle drawn through the center of each lug hole. Also referred to as the bolt pattern.

Center Bore - The hole in the center of the wheel machined to match the hub of specified vehicles with hub-centric wheels and machined to a generic size with lug centric wheels.

Hub centric - The center bore hole of a wheel matches the hub diameter of the vehicle. This centers the wheel via the center hole rather than the lug nuts.

Load rating - The maximum weight that the wheel is designed to support. To determine load rating requirements take the gross axle weight rating and divide by 2.

Lug centric - When the wheel is centered by the bolt holes/ lug nuts of the wheel, rather than by the center bore. Lug centric wheels should be balanced from the bolt holes.

Mounting pad - The surface area on the back of the wheel's center that contacts the brake drum or rotor surface.

Negative offset - When the mounting surface is closer to the disk/drum (Inside) of the wheel. Or the mounting pad is behind the centerline of the wheel. This type of wheel is commonly referred to as a deep-dish wheel. This offset is common in older vehicles and will bring the wheel/tire combination out away from the vehicle.

Offset - The offset of the wheel is the distance from the mounting pad to the centerline of the wheel.

Positive offset - The mounting pad is forward of the centerline of the wheel, towards the street side of the wheel. This is common in most front wheel drive cars and some newer trucks. Generally speaking a positive offset wheel brings the wheels closer to the center of the vehicle.

Rim width - The width of the custom wheel, measured from bead seat to bead seat not edge to edge.

Rim Diameter - The overall diameter of the wheel's bead seat, not the diameter of the rim edge.

Rim flange - The outermost edge of the wheel's rim that the clip-on weights attach to on most wheels.

Safety bead - The raised area circling the rim of the wheel and located slightly inward from the bead seat.

Zero offset - The distance from the mounting pad to the centerline of the wheel is 0.



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FordFreak

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that explains it. Thanks Fabricator.

Adam
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FordFreak

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That brings up another question then, would the rims I want a good idea for my application? The rim is an Eagle Alloy 16X8 with an offset of +2mm and a backspacing of 4 1/2. I have a 99 f-150 and am currently running a 3" spindle lift and in the future plan to go with another 2.5" with Bilstein 5100 shocks. Any recommendation on other wheels? By the info above in Fabricators post then you would not really care what the offset is more interested in the backspacing cuz in the end that is what we really care about right?

Adam
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