The rear wheel of Nomu Lab Wheel #1 that I built a while back (not yesterday)
I completely disassembled it down to the rim level.
When I was correcting lateral runout on one side,
there was enough gap on the other side that
a straightedge laid against the brake zone of the rim would lift off in spots.
But when I check the rim by itself, the straightedge appears to fit perfectly at any phase.
Hmm.
I should have taken a photo of that condition when it was a complete wheel.
I measured the rim width with calipers.
Since I took the measurement while squeezing fairly firmly,
reinserting the straightedge at that same phase is a bit snug.
↑The gap on left and right (though essentially zero) looks like this
↑This is the phase where the rim width is narrower, but
when I touch one side of the straightedge perfectly to the rim
the other side looks like this.
There's a gap, but the rim and calipers aren't parallel either.
Since one side is touching perfectly,
this side shows the combined amount of distortion from both edges.
Even when I place the straightedge at this phase,
I couldn't clearly see a gap between it and the rim.
My guess is that while the distortion pattern isn't perfectly symmetrical left and right,
there are phases on both sides where the rim width is narrower, and
when you drive out the runout on one side, the total amount of narrow rim width
shifts to one side, making it easy to spot with a straightedge.
This is an extremely rare case, but unless you do a full inspection
of the entire rim with calipers, you can't catch this kind of defect
unless you assemble it into a wheel.
There was distortion—or more like a dent—where the freewheel side was nearly runout-free
but part of the non-freewheel side had a slight inward kink,
and until the wheel was almost completely built,
it just looked like normal lateral runout and the difference wasn't apparent.
So I rebuilt it with a different rim.
660 hub, 24H, semi-comp 4-cross lacing.
I'll do the spoke twisting later.
I completely disassembled it down to the rim level.
When I was correcting lateral runout on one side,
there was enough gap on the other side that
a straightedge laid against the brake zone of the rim would lift off in spots.
But when I check the rim by itself, the straightedge appears to fit perfectly at any phase.
Hmm.
I should have taken a photo of that condition when it was a complete wheel.
I measured the rim width with calipers.
Since I took the measurement while squeezing fairly firmly,
reinserting the straightedge at that same phase is a bit snug.
↑The gap on left and right (though essentially zero) looks like this
↑This is the phase where the rim width is narrower, but
when I touch one side of the straightedge perfectly to the rim
the other side looks like this.
There's a gap, but the rim and calipers aren't parallel either.
Since one side is touching perfectly,
this side shows the combined amount of distortion from both edges.
Even when I place the straightedge at this phase,
I couldn't clearly see a gap between it and the rim.
My guess is that while the distortion pattern isn't perfectly symmetrical left and right,
there are phases on both sides where the rim width is narrower, and
when you drive out the runout on one side, the total amount of narrow rim width
shifts to one side, making it easy to spot with a straightedge.
This is an extremely rare case, but unless you do a full inspection
of the entire rim with calipers, you can't catch this kind of defect
unless you assemble it into a wheel.
There was distortion—or more like a dent—where the freewheel side was nearly runout-free
but part of the non-freewheel side had a slight inward kink,
and until the wheel was almost completely built,
it just looked like normal lateral runout and the difference wasn't apparent.
So I rebuilt it with a different rim.
660 hub, 24H, semi-comp 4-cross lacing.
I'll do the spoke twisting later.