Track and Wheelbase definition?

[mr0077]

Tom, if the backspacing of a 6" wheel is 3", there will be a negative offset due to the width of the lip (distance from the outer edge of the rim to the bead seat). If the width of the lip on a 6" Dayton is 0.25, and the backspacing is 3.25", there would be no offset.

[Don]

The US Government definition:

Footprint is defined as the product of track width (measured in
inches and rounded to the nearest tenth of an inch) times wheelbase
(measured in inches and rounded to the nearest tenth of an inch) divided
by 144 and then rounded to the nearest tenth of a square foot.

For purposes of this definition, track width is the lateral distance between
the centerlines of the base tires at ground, including the camber angle.
For purposes of this definition, wheelbase is the longitudinal distance
between front and rear wheel centerlines.

Section

[speed220mph]

Ken: You're right, except I was taking the 1/4 in. into account. Likewise, if bs is 3.00 in. and the flange isn't considered, offset is -0.25in.

Simple things can cause so much confusion it funny.