On Feb 5, 9:27*am, Bob Kuykendall wrote:
Paul,

You've probably already thought of this, but is there any reason you
can't just take your 40-19 wheel halves to a machine shop and have
them carve the center seam until the width is as you require and then
redrill the valve stem hole?

I got curious about this, so I hunted up an old 40-19 in my shop and
answered my own question. There is a very good reason that my proposed
solution wouldn't work, and it is abundantly clear once you split the
wheel halves apart.

The 40-19, unlike other similar wheels I've worked on, has its shear
web right at the plane of symmetry where the two halves join. Trying
to face off the wheel there would machine off that web, leaving you
with almost no material joining the rim and the bearing hub.

I did find an unlabeled 500x5 wheel with the same width as the 40-19
that has the shear web substantially outboard of the plan of symmetry,
such that it would be amenable to the method of narrowing I described
earlier. Like the 40-19, the halves are joined by a pattern of three
bolts. However, the bolt circle is smaller than that of the 40-19, so
it would not be practical to try to narrow that wheel and then adapt
it to the 40-19's disk and caliper arrangement.

Thanks, Bob K.