I received an LWC carbon spoke
front wheel from a customer.
The week before the Norikura Hill Climb,
they took it for a test ride,
and that's when a spoke broke.
↑Here it is
The fracture isn't at the beginning of the threads...
This wheel is the lightest model in LWC's lineup,
so the hub prioritizes weight savings—
it's an extra-light Cyber Rear SP-2.
It's a standard straight-spoke hub flange,
but the carbon section of the carbon spoke
is too large in diameter to fit through the flange holes, so
the threaded spoke head section
is passed through the hub flange,
then screwed into the threaded hole
in the carbon spoke section to lock it in place.
I removed the broken spoke on the spoke head side
and retrieved it from the nipple.
On the broken spoke's rim-side threading,
I cut full threading on the previously unthreaded
2.0mm round section of a #14 spoke.
Inside the nipple, a set-screw-like piece of the broken spoke
was trapped and couldn't be recovered.
I thought if I made a spoke head accounting for its length,
I could shift the carbon section outward
and reuse the original spoke,
but the spoke head threading
was finer than 2.0mm—finer even than #15 (1.8mm)—
so it didn't work out.
↑I wanted to do this...
↑but it wasn't possible.
Since they wanted to use it for Norikura,
I made a temporary repair with a black CX-RAY spoke as a stopgap.
I told the customer they must order spare spokes from LWC
and get it properly fixed.
I installed the CX-RAY spoke
and trued the lateral runout with minimal nipple adjustments.
The rim had shifted to the right,
so I centered it by preferentially tightening
the nipples on the freewheel side.
The repaired spoke is on the freewheel side, which is fine, but
this wheel...
is built as a reverse rim.
With a hub made for bent-head spokes,
you'd either have gotten the right-drop/left-drop wrong when threading spokes through the flange
or intentionally reversed it.
But this is a straight-spoke hub, so there's no right-drop/left-drop concept.
This isn't really an error—the hub flange's phase offset direction
forces you to build a wheel this way.
With a straight-spoke flange used in left-right tangent lacing,
nearly every hub in existence has a phase-offset flange for standard rims.
This rim might not have any hole directionality,
but if—say—a rim had hole directionality as pronounced as
the Nomulabo Wheel #9 rim,
you couldn't set the valve hole phase with a reverse-rim left-right tangent
straight-spoke hub to position it between the four spokes
of the pair with the closest final crossing.
↑This is the Nomulabo Wheel #9 rim—
photos of nipple-equipped spokes threaded through
hanging at the angle determined by spoke weight.
The rim holes are the same,
only the direction of the rim sidewall is reversed.
This rim is standard-orientation, so
if you built it beautifully with a reverse-rim straight-spoke hub,
the spokes would thread through the hub flange at an angle
that's geometrically very strained.
I've seen an example of going through the trouble to prepare a reverse-rim
straight-spoke hub and building left-right tangent lacing with a reverse rim (→here).
The link at the end of that article shows an example of
building a wheel on a standard-rim straight-spoke hub with a reverse rim,
ignoring hole directionality.
Tange's hubs—a stupid manufacturer that can't build wheels
on either standard or reverse rims (→here)—
and the aftermath (→here).
front wheel from a customer.
The week before the Norikura Hill Climb,
they took it for a test ride,
and that's when a spoke broke.
↑Here it is
The fracture isn't at the beginning of the threads...
This wheel is the lightest model in LWC's lineup,
so the hub prioritizes weight savings—
it's an extra-light Cyber Rear SP-2.
It's a standard straight-spoke hub flange,
but the carbon section of the carbon spoke
is too large in diameter to fit through the flange holes, so
the threaded spoke head section
is passed through the hub flange,
then screwed into the threaded hole
in the carbon spoke section to lock it in place.
I removed the broken spoke on the spoke head side
and retrieved it from the nipple.
On the broken spoke's rim-side threading,
I cut full threading on the previously unthreaded
2.0mm round section of a #14 spoke.
Inside the nipple, a set-screw-like piece of the broken spoke
was trapped and couldn't be recovered.
I thought if I made a spoke head accounting for its length,
I could shift the carbon section outward
and reuse the original spoke,
but the spoke head threading
was finer than 2.0mm—finer even than #15 (1.8mm)—
so it didn't work out.
↑I wanted to do this...
↑but it wasn't possible.
Since they wanted to use it for Norikura,
I made a temporary repair with a black CX-RAY spoke as a stopgap.
I told the customer they must order spare spokes from LWC
and get it properly fixed.
I installed the CX-RAY spoke
and trued the lateral runout with minimal nipple adjustments.
The rim had shifted to the right,
so I centered it by preferentially tightening
the nipples on the freewheel side.
The repaired spoke is on the freewheel side, which is fine, but
this wheel...
is built as a reverse rim.
With a hub made for bent-head spokes,
you'd either have gotten the right-drop/left-drop wrong when threading spokes through the flange
or intentionally reversed it.
But this is a straight-spoke hub, so there's no right-drop/left-drop concept.
This isn't really an error—the hub flange's phase offset direction
forces you to build a wheel this way.
With a straight-spoke flange used in left-right tangent lacing,
nearly every hub in existence has a phase-offset flange for standard rims.
This rim might not have any hole directionality,
but if—say—a rim had hole directionality as pronounced as
the Nomulabo Wheel #9 rim,
you couldn't set the valve hole phase with a reverse-rim left-right tangent
straight-spoke hub to position it between the four spokes
of the pair with the closest final crossing.
↑This is the Nomulabo Wheel #9 rim—
photos of nipple-equipped spokes threaded through
hanging at the angle determined by spoke weight.
The rim holes are the same,
only the direction of the rim sidewall is reversed.
This rim is standard-orientation, so
if you built it beautifully with a reverse-rim straight-spoke hub,
the spokes would thread through the hub flange at an angle
that's geometrically very strained.
I've seen an example of going through the trouble to prepare a reverse-rim
straight-spoke hub and building left-right tangent lacing with a reverse rim (→here).
The link at the end of that article shows an example of
building a wheel on a standard-rim straight-spoke hub with a reverse rim,
ignoring hole directionality.
Tange's hubs—a stupid manufacturer that can't build wheels
on either standard or reverse rims (→here)—
and the aftermath (→here).