Another wheel day (and so on).
A customer dropped off the front and rear wheels of a
Cosmic SL40 with rim brake setup for me to work on.
They wanted a rebuild, and the main reason
was frustration with the rear hub—specifically the maintenance
frequency for greasing the face ratchet,
which is officially every 1000 km (originally they said 5000 km),
which is just ridiculous.
I suggested that maybe the front wheel could just stay as-is
(just an inspection), but
they decided to rebuild that one too.
Mavic straight-spoke hub, 18H.
Forced radial lacing.
On the rim side, the rim holes are dimensioned to accept
standard nipples, so
I can rebuild it with regular spokes and nipples, but
on the hub side, the flanges are dimensioned to work with
special spokes that have their lower necks
abutted down to 13 gauge
to prevent spoke pull-through,
so ordinary straight spokes won't fit.
The OEM spokes are made from a material that isn't stainless,
and while they're definitely resistant to spoke pull-through,
depending on conditions (like, you know, being used on Earth),
they'll eventually get crusty with rust.
It's even worse near the ocean.
As you can see in the image above,
some of them were already showing signs of it.
Whether the customer noticed or not, I don't know,
but one spoke was bent.
When there's tension on the spokes,
the bending is hard to spot, so
↑I released the tension.
If we wanted to replace just this one spoke,
we'd have to accept Mavic's ridiculous trade practice
of requiring the shop to buy
an entire 10-pack of spare spokes
(whether Mavic distributors will sell individual spokes
to shops is theoretically possible,
but honestly I've never actually seen it happen),
so rebuilding with universal parts
might actually be cheaper in the long run.
Since the hub flanges use a hook-on design
rather than a threaded-through design,
if I loosen the nipples halfway around the wheel enough,
the wheel can be disassembled.
In the image above, you can instantly tell which nipples
I turned and which ones I never touched.
There was no trace of sealant inside the rim,
so the discoloration must have been from moisture—
water that got inside the rim—but
the brass nipples that can be turned from the outer edge
were heavily corroded.
Rebuilt.
660 hub, 18H, black CX Sprint rim,
laced outpoke radial
with black aluminum nipples.
Mavic's cosmetic sticker is very simple these days, but
it's applied on the opposite side of the wheel from the valve hole.
The fact that it appears roughly in line with
the TNI logo on the hub shell means
the hub shell's position as seen through the valve hole
lines up pretty much right with the logo.
For an 18H hub—which has so few holes
that fine position adjustment is impossible—
that was pretty spot-on.
A customer dropped off the front and rear wheels of a
Cosmic SL40 with rim brake setup for me to work on.
They wanted a rebuild, and the main reason
was frustration with the rear hub—specifically the maintenance
frequency for greasing the face ratchet,
which is officially every 1000 km (originally they said 5000 km),
which is just ridiculous.
I suggested that maybe the front wheel could just stay as-is
(just an inspection), but
they decided to rebuild that one too.
Mavic straight-spoke hub, 18H.
Forced radial lacing.
On the rim side, the rim holes are dimensioned to accept
standard nipples, so
I can rebuild it with regular spokes and nipples, but
on the hub side, the flanges are dimensioned to work with
special spokes that have their lower necks
abutted down to 13 gauge
to prevent spoke pull-through,
so ordinary straight spokes won't fit.
The OEM spokes are made from a material that isn't stainless,
and while they're definitely resistant to spoke pull-through,
depending on conditions (like, you know, being used on Earth),
they'll eventually get crusty with rust.
It's even worse near the ocean.
As you can see in the image above,
some of them were already showing signs of it.
Whether the customer noticed or not, I don't know,
but one spoke was bent.
When there's tension on the spokes,
the bending is hard to spot, so
↑I released the tension.
If we wanted to replace just this one spoke,
we'd have to accept Mavic's ridiculous trade practice
of requiring the shop to buy
an entire 10-pack of spare spokes
(whether Mavic distributors will sell individual spokes
to shops is theoretically possible,
but honestly I've never actually seen it happen),
so rebuilding with universal parts
might actually be cheaper in the long run.
Since the hub flanges use a hook-on design
rather than a threaded-through design,
if I loosen the nipples halfway around the wheel enough,
the wheel can be disassembled.
In the image above, you can instantly tell which nipples
I turned and which ones I never touched.
There was no trace of sealant inside the rim,
so the discoloration must have been from moisture—
water that got inside the rim—but
the brass nipples that can be turned from the outer edge
were heavily corroded.
Rebuilt.
660 hub, 18H, black CX Sprint rim,
laced outpoke radial
with black aluminum nipples.
Mavic's cosmetic sticker is very simple these days, but
it's applied on the opposite side of the wheel from the valve hole.
The fact that it appears roughly in line with
the TNI logo on the hub shell means
the hub shell's position as seen through the valve hole
lines up pretty much right with the logo.
For an 18H hub—which has so few holes
that fine position adjustment is impossible—
that was pretty spot-on.