I built the front wheel with a TNi (Treviso Nippon Inc.) carbon 50mm rim!
I've already built the rear wheel with an Aero 80, but
since I approached the front and rear completely differently, I'll write about them separately.
↑It looks like this. Pretty cool, right? Unlike the carbon 38,
I had to build it with spoke tension under 100 kgf,
which really made me think about things.
The rim weight has no official spec, but my actual measurement was 398g.
First, this is a perk unique to the 18-hole front wheel.
TNi makes something called a "carbon front hub."
It's been around for about 15 years now, but the thing is, it only comes in 18 holes.
It's not that 18-hole versions were left over—that's just the spec.
Since I decided to build the front wheel with 18 holes this time, I went with it.
I used Sapim CX spokes. Not CX-RAY.
Just like the Hoshi aero star bright II spokes I used the other day, these require
a hub with spoke holes that have slits—you can't fit them through and build with one that doesn't.
I built it with reverse spokes because the rim is pretty tall.
Personally, the threshold for whether I'd use radial spoking is around 50mm rim height.
（Though honestly, I almost never see radial spoking anyway.）
About why I chose CX specifically.
It comes back to the usual topic of spoke specific gravity.
This overlaps a bit with what I wrote before.
When I measured the weight of a bundle of 36 DT Champion 2.0mm plain spokes
292mm long, it came to 270g.
From that, calculating the weight of a single spoke: 270g ÷ 36 spokes =
7.5g per spoke.
Dividing that 7.5g by the length gives me 0.0257g per millimeter.
This 2.0mm plain spoke weight per millimeter is set as 100%,
and using this as my standard to determine the specific gravity of each spoke type in advance,
I can estimate spoke weight quite accurately even when the length or spoke count changes.
（In practice, I've taken many more samples to arrive at 0.0257g.）
For example, if I had 2.0mm plain spokes at 286mm length, 24 spokes:
0.0257 × 286 × 24 = 310g.
Then I just add the hub, nipples, and rim weight,
and I can know the wheel weight quite accurately without even building it.
If I swapped all of those out for CX-RAY instead,
CX-RAY has a specific gravity of 65.0%, so
310 × 0.65 = 201g.
So I tried doing the same with Sapim CX.
The CX has dimensions of 1.3mm on the thin side of the aero section and 2.8mm on the thick side,
with 2.0mm at the spoke neck and threaded section.
At 274mm, 20 spokes weighed 141.2g.
That works out to 7.06g per spoke.
The weight per millimeter came to 0.0258g.
The result: barely heavier than 2.0mm plain spokes.
Incredibly, 100.3%!
In my measurements, this is the first time I've encountered a spoke with a specific gravity over 100%.
When the specific gravity is almost identical, it means the cross-sectional area
of the 1.3mm × 2.8mm aero section is almost the same as a 2.0mm round spoke.
As a side note, Sapim publishes the weight of spoke bundles at 260mm with 64 spokes.
Sapim's plain spoke model is called "Leader," and
Leader 260mm 64 spokes has a catalog spec of 421g.
For CX, that same spec is 423g according to the catalog.
Even by Sapim's own catalog values, CX is
100.4% the weight of Leader (≈DT Champion).
This number backs up the validity of estimating spoke bundle weight
using spoke specific gravity.
TNi's carbon hub doesn't come in 24 holes, but
assuming the hub, nipples, and rim are the same here,
let me compare building with CX at 18 holes versus CX-RAY at 24 holes.
From the perspective of the CX 18-hole front wheel, the spoke specific gravity is roughly 1.5 times higher.
But the spoke count is 2/3, so
these two front wheels end up being almost the same weight.
At 50mm rim height, 24 holes looks a bit visually cluttered to me.
This wheel is a customer order, and they're thinking mainly of criterium racing.
If I were using it for criteriums and had to pick one of these two,
I'd go with the CX 18-hole.
So how does building with CX-RAY at 18 holes compare?
Compared to those two front wheels, CX-RAY at 18 holes would be about 50g lighter.
For hill climbing, that might be the way to go.
But this time, I didn't want to use CX-RAY.
It's because the spoke tension limit is 100 kgf. As I wrote earlier,
CX's specific gravity is almost the same as 2.0mm plain, meaning its cross-sectional area is too.
The other day I wrote that thicker spokes tend not to reach as high a spoke tension.
To put it another way using different terminology:
if the tension in the rim (what I call RK in this blog) is the same,
thicker spokes result in lower spoke tension.
When spoke tension reaches 100 kgf, a wheel built with thicker spokes
becomes much stiffer.
This is why I had to build with CX this time.
If I could tension it to 130 kgf like the carbon 38, maybe I'd have used CX-RAY.
Among road bike–compatible spokes, 2.0mm plain is the thickest available,
and CX has nearly the same cross-sectional area, so in theory
I can build it with the tension characteristics of 2.0mm plain.
And on top of that, I get the aerodynamic benefit.
Plus the non-aerodynamic reliability of Sapim spokes.
The downside is that it's heavy like 2.0mm plain (in this wheel's case, +50g compared to CX-RAY),
but I prioritized rigidity.
It's not at the wheel rim edge, and the rim is tall with all nipples toward the inner edge,
so weight there isn't really a problem.
Man, if I write any longer I'm gonna get laser-eyed by the cosmic horror.
For those who looked at the CX spoke length at the beginning and thought,
"So when you build a TNi carbon hub with TNi carbon 50 in radial lacing,
the spoke length is 274mm?"
Nope. I did source them at 274mm, but
I do secondary processing so the plain section doesn't stick out as much.
If I built it normally, it'd look like the image above.
In reality it looks like this. Only the flattened section is exposed.
A friendly edge for the aero profile.
This is a custom order, but
with Nomu Lab wheel spec #2 (TNi Evo hub + Sapim CX-RAY),
the 38 and 50 rims are the same price, so the wheels are too.
But (as I've mentioned before) I can't really recommend the 50mm rim for the rear wheel.
On the other hand, front 50 with rear 38 just looks uncool.
So that's how I ended up building the rear wheel with an Aero 80.
I've already built the rear wheel with an Aero 80, but
since I approached the front and rear completely differently, I'll write about them separately.
↑It looks like this. Pretty cool, right? Unlike the carbon 38,
I had to build it with spoke tension under 100 kgf,
which really made me think about things.
The rim weight has no official spec, but my actual measurement was 398g.
First, this is a perk unique to the 18-hole front wheel.
TNi makes something called a "carbon front hub."
It's been around for about 15 years now, but the thing is, it only comes in 18 holes.
It's not that 18-hole versions were left over—that's just the spec.
Since I decided to build the front wheel with 18 holes this time, I went with it.
I used Sapim CX spokes. Not CX-RAY.
Just like the Hoshi aero star bright II spokes I used the other day, these require
a hub with spoke holes that have slits—you can't fit them through and build with one that doesn't.
I built it with reverse spokes because the rim is pretty tall.
Personally, the threshold for whether I'd use radial spoking is around 50mm rim height.
（Though honestly, I almost never see radial spoking anyway.）
About why I chose CX specifically.
It comes back to the usual topic of spoke specific gravity.
This overlaps a bit with what I wrote before.
When I measured the weight of a bundle of 36 DT Champion 2.0mm plain spokes
292mm long, it came to 270g.
From that, calculating the weight of a single spoke: 270g ÷ 36 spokes =
7.5g per spoke.
Dividing that 7.5g by the length gives me 0.0257g per millimeter.
This 2.0mm plain spoke weight per millimeter is set as 100%,
and using this as my standard to determine the specific gravity of each spoke type in advance,
I can estimate spoke weight quite accurately even when the length or spoke count changes.
（In practice, I've taken many more samples to arrive at 0.0257g.）
For example, if I had 2.0mm plain spokes at 286mm length, 24 spokes:
0.0257 × 286 × 24 = 310g.
Then I just add the hub, nipples, and rim weight,
and I can know the wheel weight quite accurately without even building it.
If I swapped all of those out for CX-RAY instead,
CX-RAY has a specific gravity of 65.0%, so
310 × 0.65 = 201g.
So I tried doing the same with Sapim CX.
The CX has dimensions of 1.3mm on the thin side of the aero section and 2.8mm on the thick side,
with 2.0mm at the spoke neck and threaded section.
At 274mm, 20 spokes weighed 141.2g.
That works out to 7.06g per spoke.
The weight per millimeter came to 0.0258g.
The result: barely heavier than 2.0mm plain spokes.
Incredibly, 100.3%!
In my measurements, this is the first time I've encountered a spoke with a specific gravity over 100%.
When the specific gravity is almost identical, it means the cross-sectional area
of the 1.3mm × 2.8mm aero section is almost the same as a 2.0mm round spoke.
As a side note, Sapim publishes the weight of spoke bundles at 260mm with 64 spokes.
Sapim's plain spoke model is called "Leader," and
Leader 260mm 64 spokes has a catalog spec of 421g.
For CX, that same spec is 423g according to the catalog.
Even by Sapim's own catalog values, CX is
100.4% the weight of Leader (≈DT Champion).
This number backs up the validity of estimating spoke bundle weight
using spoke specific gravity.
TNi's carbon hub doesn't come in 24 holes, but
assuming the hub, nipples, and rim are the same here,
let me compare building with CX at 18 holes versus CX-RAY at 24 holes.
From the perspective of the CX 18-hole front wheel, the spoke specific gravity is roughly 1.5 times higher.
But the spoke count is 2/3, so
these two front wheels end up being almost the same weight.
At 50mm rim height, 24 holes looks a bit visually cluttered to me.
This wheel is a customer order, and they're thinking mainly of criterium racing.
If I were using it for criteriums and had to pick one of these two,
I'd go with the CX 18-hole.
So how does building with CX-RAY at 18 holes compare?
Compared to those two front wheels, CX-RAY at 18 holes would be about 50g lighter.
For hill climbing, that might be the way to go.
But this time, I didn't want to use CX-RAY.
It's because the spoke tension limit is 100 kgf. As I wrote earlier,
CX's specific gravity is almost the same as 2.0mm plain, meaning its cross-sectional area is too.
The other day I wrote that thicker spokes tend not to reach as high a spoke tension.
To put it another way using different terminology:
if the tension in the rim (what I call RK in this blog) is the same,
thicker spokes result in lower spoke tension.
When spoke tension reaches 100 kgf, a wheel built with thicker spokes
becomes much stiffer.
This is why I had to build with CX this time.
If I could tension it to 130 kgf like the carbon 38, maybe I'd have used CX-RAY.
Among road bike–compatible spokes, 2.0mm plain is the thickest available,
and CX has nearly the same cross-sectional area, so in theory
I can build it with the tension characteristics of 2.0mm plain.
And on top of that, I get the aerodynamic benefit.
Plus the non-aerodynamic reliability of Sapim spokes.
The downside is that it's heavy like 2.0mm plain (in this wheel's case, +50g compared to CX-RAY),
but I prioritized rigidity.
It's not at the wheel rim edge, and the rim is tall with all nipples toward the inner edge,
so weight there isn't really a problem.
Man, if I write any longer I'm gonna get laser-eyed by the cosmic horror.
For those who looked at the CX spoke length at the beginning and thought,
"So when you build a TNi carbon hub with TNi carbon 50 in radial lacing,
the spoke length is 274mm?"
Nope. I did source them at 274mm, but
I do secondary processing so the plain section doesn't stick out as much.
If I built it normally, it'd look like the image above.
In reality it looks like this. Only the flattened section is exposed.
A friendly edge for the aero profile.
This is a custom order, but
with Nomu Lab wheel spec #2 (TNi Evo hub + Sapim CX-RAY),
the 38 and 50 rims are the same price, so the wheels are too.
But (as I've mentioned before) I can't really recommend the 50mm rim for the rear wheel.
On the other hand, front 50 with rear 38 just looks uncool.
So that's how I ended up building the rear wheel with an Aero 80.