A customer brought in a Shimano C50 carbon tubular wheel for repair.

It appears to rub against the brake shoe when pedaling hard.
The Optivar design uses only 7 spokes, so
it has to distribute the total spoke tension on the non-freehub side among them,
and it's unavoidable that it deflects enough to rub the brake when
pushing down hard on the right pedal from top dead center.

But I can't just leave it at that, so I took a closer look.
The rim and brake shoe aren't set with zero clearance.

The rim was actually offset toward the freehub side—there was a centering issue.
In this case, we can tighten the non-freehub side one-way
until the rim centers up,
which is very convenient,
but looking closer, the freehub side was also a bit loose.

So I first tightened the freehub side,
then deliberately offset the center way beyond the original position,
then corrected the centering by tightening the non-freehub side.
I showed the customer both the maximum rim offset state
and the difference in spoke tension before and after work.
I can't say for certain if the brake rub is completely gone,
but the wheel deformation when sprinting is definitely reduced quite a bit.