John Harmon writes:

amdx actually said:

That's excellent advice. Since the tire bulges, I wonder if it's best
to use the wheel lugs to mount a jig which is what we measure to?
A jig, if you can't use the actual wheel.

I agree that, for our purposes, we should assume I jury rig a jig of some
sort so that there is a flat completely perpendicular plate bolted onto the
axle somehow (probably placed on the outside of the wheels using the lug
bolts or lug nuts).

Does anyone here know how to convert the 1 and 2 minutes to inches?

No, But 30 min is equal to 0.5 degrees.

Right. And the 1 and 2 minutes are 1/60th and 1/30th of a degree
respectively.

But what is 1/60th of a degree in inches?

For small angles sin(A) = A (provided A is in radians) and d times
sin(A) (hence d times A) is the displacement at a distance d caused by
an angle a. To convert to radians, multiply degrees by .0174532925199
(pi/180).

For example, 2 minutes = 1/30 deg = .0005817764173 radians so 8 inches
from the hub that corresponds to a displacement of 8 * .0005817764173 =
..00465 inches or 4.65 thousandths of an inch (0.118 mm). I image that's
hard to measure.

The suggested accuracy of 0.01 degrees corresponds to a displacement of
3.5 micrometres at 8 inches. That's less the typical width of a human
head hair.

--
Ben.