Another day, another wheel build (you know the drill).
A customer dropped off a rear wheel built with a 20mm high carbon tubular rim.
PowerWay hub, 24H
Pillar aero spokes, equal-diameter lacing both sides
Equivalent to a forced 4-across lacing pattern.
I'm going to reduce the spoke mass ratio on the non-drive side
and rebuild it as unequal-diameter lacing.
Rim weight.
The matching front wheel was actually built four years ago
(→see here).
Built.
Used CX-RAY spokes for the non-drive side.
The original Pillar aero spokes had a spoke mass ratio of
about 97.8% on the drive side and 97.5% on the non-drive side,
so it's basically like taking a #14 plain spoke
and flattening it.
I'm rebuilding this rear wheel right in front of the customer.
The provisional centerline before disassembly was spot-on, so with the same rim,
same hub, and same drive-side spokes, only the non-drive side spoke mass ratio changed.
When rebuilding, the drive-side tension is either the same or slightly lower than before.
Among the 12 spoke tensions, the maximum variance was actually higher in the original wheel.
When disassembling the original wheel, attempting to turn the drive-side nipples risked stripping them,
so I started by loosening all the non-drive side nipples first.
The original wheel was built to the absolute limit under the given constraints—
I was genuinely surprised we could tension it this high on such a light rim.
When I asked the customer to feel the non-drive side's final cross section
front-to-back on both wheels, they said:
The original wheel's spokes had a wide flattened section, making the spokes themselves resistant to deformation,
but there was still deflection.
The rebuilt wheel had deflection resistance and deformation resistance from spoke tension alone.
It's clear that this extreme unequal-diameter lacing is doing its job.
By the way, the Campagnolo Hyperon would be an example of unequal-diameter lacing with
roughly the same spoke mass ratio as this rebuild,
also 4-across equivalent, but with an even more extreme
high-low flange hub offset rim setup.
A customer dropped off a rear wheel built with a 20mm high carbon tubular rim.
PowerWay hub, 24H
Pillar aero spokes, equal-diameter lacing both sides
Equivalent to a forced 4-across lacing pattern.
I'm going to reduce the spoke mass ratio on the non-drive side
and rebuild it as unequal-diameter lacing.
Rim weight.
The matching front wheel was actually built four years ago
(→see here).
Built.
Used CX-RAY spokes for the non-drive side.
The original Pillar aero spokes had a spoke mass ratio of
about 97.8% on the drive side and 97.5% on the non-drive side,
so it's basically like taking a #14 plain spoke
and flattening it.
I'm rebuilding this rear wheel right in front of the customer.
The provisional centerline before disassembly was spot-on, so with the same rim,
same hub, and same drive-side spokes, only the non-drive side spoke mass ratio changed.
When rebuilding, the drive-side tension is either the same or slightly lower than before.
Among the 12 spoke tensions, the maximum variance was actually higher in the original wheel.
When disassembling the original wheel, attempting to turn the drive-side nipples risked stripping them,
so I started by loosening all the non-drive side nipples first.
The original wheel was built to the absolute limit under the given constraints—
I was genuinely surprised we could tension it this high on such a light rim.
When I asked the customer to feel the non-drive side's final cross section
front-to-back on both wheels, they said:
The original wheel's spokes had a wide flattened section, making the spokes themselves resistant to deformation,
but there was still deflection.
The rebuilt wheel had deflection resistance and deformation resistance from spoke tension alone.
It's clear that this extreme unequal-diameter lacing is doing its job.
By the way, the Campagnolo Hyperon would be an example of unequal-diameter lacing with
roughly the same spoke mass ratio as this rebuild,
also 4-across equivalent, but with an even more extreme
high-low flange hub offset rim setup.