Another wheel day (and so on).
I received a rear wheel from a customer with a current Ultegra
50mm high tubeless rim.
They didn't say the Optivarcal hub was bad outright,
but the rear wheel felt a bit sluggish somehow, so
I swapped out the hub and rebuilt it "just like Nomu-Lab wheel #8
except with a different rim."
Rebuilt it.
Revo Disc hub, 24H, black semi-comp, four-cross lacing,
with black aluminum nipples.
I'll do the spoking later.
The manufacturing date sticker on the hub body said "VB."
This means February 2023.
In reality, this wheel reaches the domestic Japanese market
about 4 months at the earliest after manufacturing.
The rim was manufactured by the original OEM supplier, but
instead of QR codes on both left and right, there's now only one on the left,
and the serial number appears to be a consolidated format combining
the upper digits starting with 20 or 21 and
the lower alphanumerics starting with CD.
The first two digits start with 22.
I suspect these starting digits might represent the tens and ones place of the rim's manufacturing year,
but I don't have confirmation yet.
For wheels from this rim manufacturer's own wheel brand,
DT wheels, and Bontrager wheels,
this serial number itself is used to manage individual rim identification,
but Shimano applies a separate barcode + serial number sticker
on the left side of the rim, using the same format
even for aluminum rim models.
Someone asked if the "LEGO consideration" is homemade.
To answer: the brand isn't LEGO—the penguin on the right is Nanoblock,
which comes as a kit with just enough pieces plus some spare blocks.
I received it from a customer in a loose plastic bag.
The larger one on the left was already assembled when I received it from a customer,
and it's a penguin from the Petit Block brand sold at Daiso.
By the way, there's no compatibility between Nanoblock and Petit Block.
Back to the wheel story.
This Ultegra rim and the Aiolus Pro 51 rim from a few days ago share the same OEM supplier,
but the Aiolus Pro 51's rim was quite heavy in terms of height/weight ratio.
However, this Ultegra rim with just 1mm difference in rim height
is somewhat light in terms of height/weight ratio.
I suspect Bontrager specifically ordered Aiolus to make theirs deliberately heavier.
When comparing wheels with light versus heavy rims and tires,
roughly speaking, heavier rims create a zone where it becomes easier at speed on flat terrain once you get rolling,
while lighter rims clearly feel faster climbing,
but more precisely, the sweet speed range is determined by the rim's outer diameter weight.
Back when only rim brakes existed, I heard from several fit cyclists that Mavic's budget Aksium model
"actually rides faster on flats than the Ksyrium,"
which is because the Aksium rim weighs just under 500g—about 100g heavier than the Ksyrium.
So, for example, with Shimano wheels, would the budget WH-RS21 with a heavier rim run faster on flats
than Dura-Ace C24? Or with Fulcrum, would Racing 7 run faster on flats than Racing Zero?
The answer is no. Among complete wheel manufacturers, only Mavic uses
specialized spokes with higher spoke weight ratios even in budget models,
making them properly stiff.
Under the condition that you can only use the cheapest complete wheels
and aren't evaluating spare parts availability,
Mavic is the strongest wheel manufacturer.
↑The claimed dimensions (numerical mm) for this Ultegra rim.
I've added the Aiolus's internal width and rim height in blue.
I've also added the outer width.
Apart from the difference in rim internal width,
the Aiolus Pro 51 rim has a shape as if the carbon layering of
the Ultegra C50 rim has been increased.
The odd rim heights of 37mm and 51mm found in the Aiolus Pro line,
I suspect, weren't specified by Bontrager,
but rather resulted from taking the 36mm and 50mm rim designs
and increasing the carbon layering accordingly.
That said, it's not as simple as making a 50mm rim first
and then adding 1mm of carbon on top.
The thickness of the rim hole on the inner side is nearly identical between Shimano and Aiolus.
The Aiolus Pro 51 is a 2022 model, but
the Aiolus Pro 37 is a 2021 model, and despite being a year older,
it has an older design (not that old is bad, just less contemporary),
with internal/external widths the same as Shimano's C36 at 21/28mm,
differing only in rim height by 1mm.
The 2024 model Aiolus Pro 37V and 49V with 25mm internal width
have the taller rim height at actually 1mm lower than 50mm high,
which contradicts the "increased layering from 50mm rim" theory,
but the Aiolus Pro 51 and Aiolus Pro 49V have different front hubs yet
show no major weight difference, identical spoke ratios and nearly identical lengths,
yet the claimed front wheel weight is 725g and 690g respectively.
So most of this 35g difference is likely due to rim weight, and
considering the difference of +2mm internal width and -2mm rim height
compared to the Aiolus Pro 51 rim, under equal stiffness design targets,
these factors would nearly cancel out,
so I believe the Aiolus Pro 51 was deliberately made heavier
with rim stiffness and inertia during flat-ground high-speed cruising in mind.
In terms of wheel structure,
Shimano's rear wheel uses what's called Optivarcal,
a meaninglessly irregular hub lacing pattern for 0-spoke lacing on the few-spoke side a 2:1 lacing 24H,
while Aiolus's rear wheel is symmetrical 24H,
but if I were to build both the Aiolus Pro 51 rim and
the Ultegra C50 rim identically
using a Tani Revo Disc hub, the result would be wheels that,
despite the same rim height,
could be used interchangeably on flat versus slightly climbing courses
due to the rim weight difference.
Someone might suggest just adding weight evenly around the Ultegra rim
for flat riding, but doing so would change the inertia characteristics
while the added weight doesn't contribute to rim stiffness,
so you wouldn't get the same feel.
To truly grasp this feel, I'd need to know the actual measured weight of the Ultegra rim,
but I don't see a need to disclose that, so
I won't tell you.
↑ugh, this guy's rambling and being snippy about it
Sorry for the wait! Please take a look at this image!
Here's the rear rim of the R8170-C50-TL!
This is from the article I posted the other day,
and I'm also posting an image of the Aiolus Pro 51's rear rim!
↑STOP IT!
I received a rear wheel from a customer with a current Ultegra
50mm high tubeless rim.
They didn't say the Optivarcal hub was bad outright,
but the rear wheel felt a bit sluggish somehow, so
I swapped out the hub and rebuilt it "just like Nomu-Lab wheel #8
except with a different rim."
Rebuilt it.
Revo Disc hub, 24H, black semi-comp, four-cross lacing,
with black aluminum nipples.
I'll do the spoking later.
The manufacturing date sticker on the hub body said "VB."
This means February 2023.
In reality, this wheel reaches the domestic Japanese market
about 4 months at the earliest after manufacturing.
The rim was manufactured by the original OEM supplier, but
instead of QR codes on both left and right, there's now only one on the left,
and the serial number appears to be a consolidated format combining
the upper digits starting with 20 or 21 and
the lower alphanumerics starting with CD.
The first two digits start with 22.
I suspect these starting digits might represent the tens and ones place of the rim's manufacturing year,
but I don't have confirmation yet.
For wheels from this rim manufacturer's own wheel brand,
DT wheels, and Bontrager wheels,
this serial number itself is used to manage individual rim identification,
but Shimano applies a separate barcode + serial number sticker
on the left side of the rim, using the same format
even for aluminum rim models.
Someone asked if the "LEGO consideration" is homemade.
To answer: the brand isn't LEGO—the penguin on the right is Nanoblock,
which comes as a kit with just enough pieces plus some spare blocks.
I received it from a customer in a loose plastic bag.
The larger one on the left was already assembled when I received it from a customer,
and it's a penguin from the Petit Block brand sold at Daiso.
By the way, there's no compatibility between Nanoblock and Petit Block.
Back to the wheel story.
This Ultegra rim and the Aiolus Pro 51 rim from a few days ago share the same OEM supplier,
but the Aiolus Pro 51's rim was quite heavy in terms of height/weight ratio.
However, this Ultegra rim with just 1mm difference in rim height
is somewhat light in terms of height/weight ratio.
I suspect Bontrager specifically ordered Aiolus to make theirs deliberately heavier.
When comparing wheels with light versus heavy rims and tires,
roughly speaking, heavier rims create a zone where it becomes easier at speed on flat terrain once you get rolling,
while lighter rims clearly feel faster climbing,
but more precisely, the sweet speed range is determined by the rim's outer diameter weight.
Back when only rim brakes existed, I heard from several fit cyclists that Mavic's budget Aksium model
"actually rides faster on flats than the Ksyrium,"
which is because the Aksium rim weighs just under 500g—about 100g heavier than the Ksyrium.
So, for example, with Shimano wheels, would the budget WH-RS21 with a heavier rim run faster on flats
than Dura-Ace C24? Or with Fulcrum, would Racing 7 run faster on flats than Racing Zero?
The answer is no. Among complete wheel manufacturers, only Mavic uses
specialized spokes with higher spoke weight ratios even in budget models,
making them properly stiff.
Under the condition that you can only use the cheapest complete wheels
and aren't evaluating spare parts availability,
Mavic is the strongest wheel manufacturer.
↑The claimed dimensions (numerical mm) for this Ultegra rim.
I've added the Aiolus's internal width and rim height in blue.
I've also added the outer width.
Apart from the difference in rim internal width,
the Aiolus Pro 51 rim has a shape as if the carbon layering of
the Ultegra C50 rim has been increased.
The odd rim heights of 37mm and 51mm found in the Aiolus Pro line,
I suspect, weren't specified by Bontrager,
but rather resulted from taking the 36mm and 50mm rim designs
and increasing the carbon layering accordingly.
That said, it's not as simple as making a 50mm rim first
and then adding 1mm of carbon on top.
The thickness of the rim hole on the inner side is nearly identical between Shimano and Aiolus.
The Aiolus Pro 51 is a 2022 model, but
the Aiolus Pro 37 is a 2021 model, and despite being a year older,
it has an older design (not that old is bad, just less contemporary),
with internal/external widths the same as Shimano's C36 at 21/28mm,
differing only in rim height by 1mm.
The 2024 model Aiolus Pro 37V and 49V with 25mm internal width
have the taller rim height at actually 1mm lower than 50mm high,
which contradicts the "increased layering from 50mm rim" theory,
but the Aiolus Pro 51 and Aiolus Pro 49V have different front hubs yet
show no major weight difference, identical spoke ratios and nearly identical lengths,
yet the claimed front wheel weight is 725g and 690g respectively.
So most of this 35g difference is likely due to rim weight, and
considering the difference of +2mm internal width and -2mm rim height
compared to the Aiolus Pro 51 rim, under equal stiffness design targets,
these factors would nearly cancel out,
so I believe the Aiolus Pro 51 was deliberately made heavier
with rim stiffness and inertia during flat-ground high-speed cruising in mind.
In terms of wheel structure,
Shimano's rear wheel uses what's called Optivarcal,
while Aiolus's rear wheel is symmetrical 24H,
but if I were to build both the Aiolus Pro 51 rim and
the Ultegra C50 rim identically
using a Tani Revo Disc hub, the result would be wheels that,
despite the same rim height,
could be used interchangeably on flat versus slightly climbing courses
due to the rim weight difference.
Someone might suggest just adding weight evenly around the Ultegra rim
for flat riding, but doing so would change the inertia characteristics
while the added weight doesn't contribute to rim stiffness,
so you wouldn't get the same feel.
To truly grasp this feel, I'd need to know the actual measured weight of the Ultegra rim,
but I don't see a need to disclose that, so
I won't tell you.
↑ugh, this guy's rambling and being snippy about it
Sorry for the wait! Please take a look at this image!
Here's the rear rim of the R8170-C50-TL!
This is from the article I posted the other day,
and I'm also posting an image of the Aiolus Pro 51's rear rim!
↑STOP IT!