Bobby,
This information was compiled from various web sites as wheels manufactures
refer to the offset in mm, either positive or negative from actual wheel
center. So yeah, mm is the unit of measurements for inside the chart.
The offset is set in stone for a particular wheel width with regards to
backspacing, as the chart depicts. Be sure to remember that backspacing is
measured at the wheel mounting surface and offset is measure at the exact
center of the wheel. I was measuring for the rear end, so I used a piece
of 1 x 4, held it in the fender well against the bed side and let the
bottom rest on the axle housing to form a line that I could measure. I
then made a jig out of a 15 inch piece of flat steel, drilled holes so I
could mount it to the rear end in place of a wheel/tire. This gave me
something to measure and would give me the backspacing I would need. Again
be sure to give about 3/4 inch extra for the amount the tire hangs over the
rim.
All this needs to clear the bed side. So i actually measure 5 inches
between the two devices, most wheels came with 3 3/4 inches backspacing so
add the 3/4 inches for the tire and that gave 4.5 inches. So i'd have 1/2
inch clearance between the tire edge and bedside.
One thing most wheel dealers stated, If you put a tire on a wheel, they
can't take it back to the manufacture for refund. So i bought mine, brought
one home, made sure all my measurements were correct and verified the fit.
Then back to the tire store to get 'em mounted. Good luck.. --wayne
At 09:24 AM 3/2/04 -0600, Bobby D Keeland wrote:
>Thanks for the information. What are the units of measure for the
>Backspacing to Offset Conversion Chart? You have inches along the top and
>left side, but there is no way that the units in the main body of the chart
>are inches. Does this chart mix inches and mm? I'm sure that I will need
>this information when I go talk with a wheel vendor.
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