Correct wheels and offset

[bhayden]

So all the 16" wheels "Trailer Tires & Wheels" have a 5.5" bolt circle and a 4.25" center bore. Hopefully that's correct for my '78 Argosy? But the different styles have different offsets. All the way from -8 to +5mm. How do I figure out which one will give me the best fenderwell clearance? -Bernie

[bake315]

Originally Posted by bhayden

So all the 16" wheels "Trailer Tires & Wheels" have a 5.5" bolt circle and a 4.25" center bore. Hopefully that's correct for my '78 Argosy? But the different styles have different offsets. All the way from -8 to +5mm. How do I figure out which one will give me the best fenderwell clearance? -Bernie

Bernie -

If I'm not mistaken, mine are zero offset.

[Bob Thompson]

Hi Bernie, You can compare the new wheels to your existing wheels by comparing the "back spacing". Back Spacing is the distance on the back side of the wheel from the bolt mounting surface to backside edge of the rim. Lay one of your wheels face down, lay a straight edge across the wheel so that it rests across the wheel on the outermost edge of wheel rim flange. Now measure from the bolt mounting surface to the nearest face of the straight edge. This is your backspacing number. When you talk to wheel companies, ask them what their backspacing is and compare it to your original wheels. If your wheels are 7" wide, and your backspacing is 3.5", that means the backside mounting surface is in the exact middle of the wheel. The plus 5mm or minus 8mm are added or subtracted accordingly to get the new backspacing number for the wheels. Variations of the +5mm or -8mm aren't very large in the scheme of things. When backspacing variations go over 1/2" you will need to verify clearance in the wheel wells. IF you want your wheels to stick out farther, decrease the backspacing. If you want them recessed into the wheelwell farther, increase the backspacing. Hope this helps.