A customer left me their current Dura-Ace C50
tubeless front and rear wheels for inspection.
I received them on April 16th of this year.
They wanted an inspection, which is fine,
but the reason I hadn't written about them until now was
because I planned to do it at the same time as
rebuilding the C36 tubular wheels.
The R9270's C36 and C50 use
custom spokes with approximately 62% spoke weight ratio,
while the R8170's C36 and C50 use
custom spokes with approximately 71% spoke weight ratio.
I really hate wheels that can't be fixed or are difficult to fix
due to poor parts availability,
but both of these have spoke weight ratios
slightly off from the CX-RAY (65%) or CX Sprint (78%).
As a temporary measure until original spokes can be sourced,
a quick repair with CX-RAY spokes would be acceptable,
but given Shimano's past supply patterns,
it's questionable just how long original spokes will even be available.
Factory-built wheels don't usually experience natural spoke breakage
unrelated to external damage within 1-2 years of use.
With Dura-Ace, it's probably not until after the next generation
Dura-Ace hits the market. And when that happens,
"parts for the previous Dura-Ace" suddenly become hard to find.
If the spoke weight ratio were compatible with universal spokes,
it wouldn't be much of a problem even if original spokes became unavailable.
Oops. Spoke availability wasn't really the main topic for today.
These wheels show paint chipping and rust forming
at a level where you can feel the texture difference by scratching the spokes with your fingernail.
This is a commonly seen symptom with Shimano wheels,
but it rarely happens with DT or Sapim spokes.
Hmm—hardly befitting of a high-end wheel,
really tanks the joy of ownership.
According to the customer, these wheels
were purchased right after they came out.
Based on the manufacturing date visible on the hub sticker (→here),
TC indicates March 2021.
By the way, the linked article is convenient enough that I
have it bookmarked in my browser (←doesn't matter).
The front wheel I rebuilt today uses the hub from
the wheel I sourced later,
but its manufacturing date is TJ, so October 2021.
The C36 from the first wheel I sourced was also purchased
right after it came out, but even that's
TD, so April 2021.
The R8170 hub I mentioned the other day
is UF, so June 2022.
The original spokes from the front wheel I rebuilt today (TJ)
had "mac spoke" stamped on them.
The same is true for the front wheel I bought first (TD).
Though the stamping position is pretty sloppy—lots of misalignment
But on the C50 front wheel (TC) this time,
the spokes had no stamping at all.
I initially thought the stamping was there at first
and was removed later, but
it turns out to be the opposite—only the very early production batches
came assembled with unstamped spokes
(based on what I can determine at this point).
↑WH-7701 spokes
↑WH-7900 spokes
These might be somewhat better, wouldn't you say?
For examples of mac spokes and spokes similar to R9270 spokes
with the same flattening process that have rusted severely,
see (→here).
tubeless front and rear wheels for inspection.
I received them on April 16th of this year.
They wanted an inspection, which is fine,
but the reason I hadn't written about them until now was
because I planned to do it at the same time as
rebuilding the C36 tubular wheels.
The R9270's C36 and C50 use
custom spokes with approximately 62% spoke weight ratio,
while the R8170's C36 and C50 use
custom spokes with approximately 71% spoke weight ratio.
I really hate wheels that can't be fixed or are difficult to fix
due to poor parts availability,
but both of these have spoke weight ratios
slightly off from the CX-RAY (65%) or CX Sprint (78%).
As a temporary measure until original spokes can be sourced,
a quick repair with CX-RAY spokes would be acceptable,
but given Shimano's past supply patterns,
it's questionable just how long original spokes will even be available.
Factory-built wheels don't usually experience natural spoke breakage
unrelated to external damage within 1-2 years of use.
With Dura-Ace, it's probably not until after the next generation
Dura-Ace hits the market. And when that happens,
"parts for the previous Dura-Ace" suddenly become hard to find.
If the spoke weight ratio were compatible with universal spokes,
it wouldn't be much of a problem even if original spokes became unavailable.
Oops. Spoke availability wasn't really the main topic for today.
These wheels show paint chipping and rust forming
at a level where you can feel the texture difference by scratching the spokes with your fingernail.
This is a commonly seen symptom with Shimano wheels,
but it rarely happens with DT or Sapim spokes.
Hmm—hardly befitting of a high-end wheel,
really tanks the joy of ownership.
According to the customer, these wheels
were purchased right after they came out.
Based on the manufacturing date visible on the hub sticker (→here),
TC indicates March 2021.
have it bookmarked in my browser (←doesn't matter).
The front wheel I rebuilt today uses the hub from
the wheel I sourced later,
but its manufacturing date is TJ, so October 2021.
The C36 from the first wheel I sourced was also purchased
right after it came out, but even that's
TD, so April 2021.
The R8170 hub I mentioned the other day
is UF, so June 2022.
The original spokes from the front wheel I rebuilt today (TJ)
had "mac spoke" stamped on them.
The same is true for the front wheel I bought first (TD).
But on the C50 front wheel (TC) this time,
the spokes had no stamping at all.
I initially thought the stamping was there at first
and was removed later, but
it turns out to be the opposite—only the very early production batches
came assembled with unstamped spokes
(based on what I can determine at this point).
↑WH-7701 spokes
↑WH-7900 spokes
These might be somewhat better, wouldn't you say?
For examples of mac spokes and spokes similar to R9270 spokes
with the same flattening process that have rusted severely,
see (→here).