It's wheels again today (and so on).
From a customer
I received a wheel from a brand called VCYCLE
called nopea38. It's a non-tubeless WO (wide clincher) carbon rim.
The number at the end indicates rim depth—there are others like 50 as well.
The rim eyelets are evenly spaced, but
the hub is a Novatech unit with the flange holes offset in alternating phases,
and the spokes are MAC aero spokes with slit holes in a 0-degree (tangent) build.
It's not that a spoke is missing—
the nipple is broken.
This wasn't exactly a coincidence—there were particular circumstances.
Notice that the spoke isn't visible at all through the break in the nipple.
Starting from the valve hole, I carefully loosened all the nipples and disassembled the wheel,
leaving just 4 spokes completely untouched.
When I pulled it out from the rim to examine it—
the spokes are far too short. I calculate spoke length so that it reaches
roughly flush with the rim at the nipple end, but
at minimum it needs to reach to the bottom of the slot and be flush with the rim—
otherwise it will cause nipple breakage.
With spokes this short, you can't rule out a causal relationship with the nipple failure.
What's more, these nipples aren't standard parts—
they're actually dimensioned with larger ends that look like they should resist breakage.
For one to break like this is extreme.
If this same model from this brand hasn't corrected the spoke length issue,
I'd expect the same failures to occur repeatedly.
The spoke length measured 265mm.
The theoretical value for a hub without offset flange holes would be 267.02mm,
and we'd add a correction factor for the hub's flange offset.
265mm × 20 spokes = 133.7g, giving a spoke specific gravity of
0.98157256... or about 98%.
Sapim CX is 100.3%, so at 98% I could even replace a single spoke with 14-gauge plain (100%)
and avoid variation in deformation across the rest of the spokes.
However, replacing just one spoke doesn't solve the problem of the remaining spokes being too short.
The customer probably didn't realize the spokes were this short,
but they've expressed distrust of the spokes and want a complete replacement.
And when doing that, they'd like to change from black spokes to silver.
Built it.
Novatech offset flange hub, 20H, CX Sprint 0-degree build
(I didn't call it radial since the spoke path deviates from a true radial line).
I could have used CX, but I decided CX Sprint was sufficient
to achieve adequate stiffness without going that far.
This wheel came to us before CX Sprint was consistently available,
and even for previously ordered wheels from that period and earlier,
there are many examples where we've changed the spec to CX Sprint.
From a customer
I received a wheel from a brand called VCYCLE
called nopea38. It's a non-tubeless WO (wide clincher) carbon rim.
The number at the end indicates rim depth—there are others like 50 as well.
The rim eyelets are evenly spaced, but
the hub is a Novatech unit with the flange holes offset in alternating phases,
and the spokes are MAC aero spokes with slit holes in a 0-degree (tangent) build.
It's not that a spoke is missing—
the nipple is broken.
This wasn't exactly a coincidence—there were particular circumstances.
Notice that the spoke isn't visible at all through the break in the nipple.
Starting from the valve hole, I carefully loosened all the nipples and disassembled the wheel,
leaving just 4 spokes completely untouched.
When I pulled it out from the rim to examine it—
the spokes are far too short. I calculate spoke length so that it reaches
roughly flush with the rim at the nipple end, but
at minimum it needs to reach to the bottom of the slot and be flush with the rim—
otherwise it will cause nipple breakage.
With spokes this short, you can't rule out a causal relationship with the nipple failure.
What's more, these nipples aren't standard parts—
they're actually dimensioned with larger ends that look like they should resist breakage.
For one to break like this is extreme.
If this same model from this brand hasn't corrected the spoke length issue,
I'd expect the same failures to occur repeatedly.
The spoke length measured 265mm.
The theoretical value for a hub without offset flange holes would be 267.02mm,
and we'd add a correction factor for the hub's flange offset.
265mm × 20 spokes = 133.7g, giving a spoke specific gravity of
0.98157256... or about 98%.
Sapim CX is 100.3%, so at 98% I could even replace a single spoke with 14-gauge plain (100%)
and avoid variation in deformation across the rest of the spokes.
However, replacing just one spoke doesn't solve the problem of the remaining spokes being too short.
The customer probably didn't realize the spokes were this short,
but they've expressed distrust of the spokes and want a complete replacement.
And when doing that, they'd like to change from black spokes to silver.
Built it.
Novatech offset flange hub, 20H, CX Sprint 0-degree build
(I didn't call it radial since the spoke path deviates from a true radial line).
I could have used CX, but I decided CX Sprint was sufficient
to achieve adequate stiffness without going that far.
This wheel came to us before CX Sprint was consistently available,
and even for previously ordered wheels from that period and earlier,
there are many examples where we've changed the spec to CX Sprint.