I stocked spokes for the front wheel of the current generation Altegra C60.
Since both sides are a lazy-design 262mm spec,
as "Altegra C60 front wheel"
there's only one spoke length.
The WH-R8170-C60 wheel
I've never actually seen in person,
so to speak like Tsuchinoko or Nessie,
its very existence is doubted,
so an opportunity to repair it may never come.
Yet I stocked spare spokes for it anyway,
and for a rather nefarious purpose.
The C60 wheels found on current Dura-Ace and Altegra,
but Altegra comes only in tubeless rim spec,
while Dura-Ace also has a tubular rim version.
The Dura-Ace C60 is, strictly speaking,
model number WH-R9270-C60-HR-TL (or TU),
with thicker spokes.
In the original text from Shimano's site,
it says "spokes with increased rigidity,"
but within the scope of equal-diameter lacing on both sides,
increasing spoke gauge (making spokes thicker)
can only result in the idea of
"gaining rigidity as a tradeoff for increased weight."
It's strange that a manufacturer who once made
wheels with different diameter lacing on each side
is saying this sort of thing now.
On Shimano's old optical gear display for three-speed internal hub shifters for utility bikes,
the three-speed display was labeled "fast·flat·easy,"
(nowadays it's 1·2·3),
and I thought, why do they only write "good things"?
But if we're going by the logic of writing "fast·flat·easy" as "heavy·flat·slow,"
then for Dura-Ace C36 and C50,
it would say "adopted spokes with reduced rigidity."
Yet Dura-Ace C60-HR
is a wheel that likely doesn't sell as well
as C36 or C50, with development and manufacturing costs
actually higher.
Only C60-HR has the front wheel laced 2:1,
and comes with a dedicated front hub.
The spokes are 262mm×16 and 244mm×8.
The Altegra C60 front wheel
uses the same hub as C36 and C50 with equal lacing on both sides,
with spokes of 262mm×24.
Shimano has long had a curious notation for aero spokes on complete wheelsets,
writing what appear to be the dimensions of the round butted spokes
before they're flattened.
For Dura-Ace C36 and C50,
this is 2.0-1.5-2.0mm.
Round butted spokes of these dimensions
have a spoke weight ratio of about 65% or less,
and when processed into Sapim's CX-RAY
or DT's Aerolite, they're around 64%,
but the spokes on Dura-Ace C36 and C50
are about 62%, lighter than those.
Sapim's CX has a spoke weight ratio of about 101.3%,
which I interpret as #14 plain (100% spoke weight ratio)
converted to aero spoke form,
but if Shimano adopted spokes of the same dimensions
for their wheels,
would they be labeled 2.0-2.0-2.0mm?
(They should be.)
The spokes on Altegra C36, C50, and C60
are, according to the manufacturer's specs,
all 2.0-1.6-2.0mm dimensions,
and except for length, they're the same spokes.
The C36 spoke weight ratio is about 71%.
For C50, I haven't measured enough samples
to be reliable.
I'll discuss C60 later.
Only the Dura-Ace C60-HR spokes
are 2.0-1.8-2.0mm,
which, if round butted,
would be equivalent to DT's Competition or Sapim's Race.
So the spoke weight ratio would be thought to be around 85%,
but judging from Shimano's spoke tendencies,
I suspect it's actually around 80%.
Assuming the Dura-Ace C60-HR-TL
and Altegra C60-TL tubeless rims
weigh the same, the total spoke length on the front wheel
with 244mm mixed in alongside 262mm
makes Dura-Ace shorter, and the
front hub weight is also expected to be lighter on Dura-Ace,
but the C60-HR spoke weight ratio
transcends those weight factors,
so where Altegra C60-TL front wheel
is listed at 738g,
the Dura-Ace C60-HR-TL front wheel comes in at
751g.
This time, I stocked the 262mm spokes
for the Altegra C60 front wheel,
and for an evil reverse-laced different-diameter purpose,
the C60-HR 262mm might have been better.
The nipples aren't supplied separately in a bag
but come threaded partway onto the spoke threads,
which we separate upon receiving stock.
Still, on the spoke threads
there's a remarkably dark blue
thread-locking compound applied.
Forty-eight spokes weighed 241.0g.
Calculating the spoke weight ratio from here:
241.0÷48÷262÷0.0257＝
0.7456609330...,
so roughly 74.5%.
For C36 spokes this comes to 70.8% or 71.1%,
so I call it about 71%,
but the C36 front wheel isalso a shortcut design with 286mm on both sides,
24mm longer than C60,
so the proportion of #14 plain section at both ends increases,
and these spare spokes have thread-locking compound
applied generously on the threads...
but these factors alone
wouldn't account for a 3% or greater change in spoke weight ratio.
Measuring the flattened butted section thickness with calipers,
C36 spokes are about 1.2mm,
C60 spokes are about 1.3mm.
Also, when passing through the same slot of the spoke truing tool,
the C60 spokes clearly fit tighter,
noticeably different to the touch.
And when I grabbed the butted section midway (not the spoke ends)
with two fingers and flexed the spoke within its elastic range,
the C60 spokes clearly showed
less deformation (stiffer).
If the original round butted spokes
had the same spoke weight ratio,
whether 1.2mm or 1.3mm thick,
the spoke weight ratio wouldn't change.
Out of curiosity I checked the width too,
and both C36 and C60 were 1.9mm, nearly identical.
If this difference is manufacturing tolerance,
then C36 spokes with 74.5% spoke weight ratio
could be in circulation,
but spokes differing 3% in weight ratio
cannot be treated as the same spoke.
If hypothetically the bundle weight of these C60 262mm spokes
with 74.5% spoke weight ratio and 48 spokes
were reduced in number to match a weight at 71% ratio,
the theoretical value would be 45.7 spokes.
Even if we cleaned off all the thread-locking compound
applied to the threads of 48 spokes and collected it,
it couldn't amount to 2.3 spokes' worth of weight.
Whether this is intentional variation or a particular manufacturing batch
that produced thicker spokes, I don't know,
but either way, according to Shimano,
these are spokes called 2.0-1.6-2.0mm.
"Intentionally make different versions with 3.5% different spoke weight ratio
but call them all 2.0-1.6-2.0mm butted"
or "make the same 2.0-1.6-2.0mm aero spokes
and they come out 3.5% different in spoke weight ratio"
↑Either way, they're cutting way too many corners.
284mm, 24 spokes
264mm, 24 spokes
Both images above are CX-RAY,
and I selected lengths close to 286mm and 262mm
that we have in stock.
The 284mm spoke weight ratio is
111.9÷24÷284÷0.0257＝
0.6388036118...,
so around 63.8% to 63.9%.
The 264mm spoke weight ratio is
103.8÷24÷264÷0.0257＝
0.6374542807...,
so 63.7% is fair.
The CX-RAY's #14 plain sections at both ends—
the thread end is constant and the head end varies somewhat,
but for these 264mm and 284mm they were nearly the same.
So the 284mm with relatively longer butted section
should have smaller spoke weight ratio,
but this time it didn't.
Though it's only about 0.2% difference,
which is the level of acceptable tolerance.
One more thing about these C60 spare spokes—
around the spoke-holding crush marking on the thread end
(which I don't use),
there are numerous scuff marks, or paint scratches.
↑This is a spoke extracted from a new C36 wheel,
and shows no such marks.
What's this? Paint so fragile it chips easily when jostled in a bag? Or is this also "individual variation"?
Shimano wheel spokes,
since the beginning—or rather from the original 7700 series on
(except for the 7800 series silver spokes)—
always have paint that chips quickly,
and rust spots soon appear,
so after some years of use the wheels look dirty,
which damages the bike's aesthetics,
and makes me feel these aren't worth the price,
diminishing the joy of ownership.
※A note to parents:
This may be a sign to replace them.
Just as banana peels inevitably turn brown,
maybe if you think of this as "just how it is,"
you wouldn't mind it.
Personally, I do mind it.
Finally. In the image above, on the left is
the new C60 spare spoke we just stocked,
and on the right is a C36 spoke extracted from a new wheel.
You can see the difference in the thread-locking compound darkness.
Since both sides are a lazy-design 262mm spec,
as "Altegra C60 front wheel"
there's only one spoke length.
The WH-R8170-C60 wheel
I've never actually seen in person,
so to speak like Tsuchinoko or Nessie,
its very existence is doubted,
so an opportunity to repair it may never come.
Yet I stocked spare spokes for it anyway,
and for a rather nefarious purpose.
The C60 wheels found on current Dura-Ace and Altegra,
but Altegra comes only in tubeless rim spec,
while Dura-Ace also has a tubular rim version.
The Dura-Ace C60 is, strictly speaking,
model number WH-R9270-C60-HR-TL (or TU),
with thicker spokes.
In the original text from Shimano's site,
it says "spokes with increased rigidity,"
but within the scope of equal-diameter lacing on both sides,
increasing spoke gauge (making spokes thicker)
can only result in the idea of
"gaining rigidity as a tradeoff for increased weight."
It's strange that a manufacturer who once made
wheels with different diameter lacing on each side
is saying this sort of thing now.
On Shimano's old optical gear display for three-speed internal hub shifters for utility bikes,
the three-speed display was labeled "fast·flat·easy,"
(nowadays it's 1·2·3),
and I thought, why do they only write "good things"?
But if we're going by the logic of writing "fast·flat·easy" as "heavy·flat·slow,"
then for Dura-Ace C36 and C50,
it would say "adopted spokes with reduced rigidity."
Yet Dura-Ace C60-HR
is a wheel that likely doesn't sell as well
as C36 or C50, with development and manufacturing costs
actually higher.
Only C60-HR has the front wheel laced 2:1,
and comes with a dedicated front hub.
The spokes are 262mm×16 and 244mm×8.
The Altegra C60 front wheel
uses the same hub as C36 and C50 with equal lacing on both sides,
with spokes of 262mm×24.
Shimano has long had a curious notation for aero spokes on complete wheelsets,
writing what appear to be the dimensions of the round butted spokes
before they're flattened.
For Dura-Ace C36 and C50,
this is 2.0-1.5-2.0mm.
Round butted spokes of these dimensions
have a spoke weight ratio of about 65% or less,
and when processed into Sapim's CX-RAY
or DT's Aerolite, they're around 64%,
but the spokes on Dura-Ace C36 and C50
are about 62%, lighter than those.
Sapim's CX has a spoke weight ratio of about 101.3%,
which I interpret as #14 plain (100% spoke weight ratio)
converted to aero spoke form,
but if Shimano adopted spokes of the same dimensions
for their wheels,
would they be labeled 2.0-2.0-2.0mm?
(They should be.)
The spokes on Altegra C36, C50, and C60
are, according to the manufacturer's specs,
all 2.0-1.6-2.0mm dimensions,
and except for length, they're the same spokes.
The C36 spoke weight ratio is about 71%.
For C50, I haven't measured enough samples
to be reliable.
I'll discuss C60 later.
Only the Dura-Ace C60-HR spokes
are 2.0-1.8-2.0mm,
which, if round butted,
would be equivalent to DT's Competition or Sapim's Race.
So the spoke weight ratio would be thought to be around 85%,
but judging from Shimano's spoke tendencies,
I suspect it's actually around 80%.
Assuming the Dura-Ace C60-HR-TL
and Altegra C60-TL tubeless rims
weigh the same, the total spoke length on the front wheel
with 244mm mixed in alongside 262mm
makes Dura-Ace shorter, and the
front hub weight is also expected to be lighter on Dura-Ace,
but the C60-HR spoke weight ratio
transcends those weight factors,
so where Altegra C60-TL front wheel
is listed at 738g,
the Dura-Ace C60-HR-TL front wheel comes in at
751g.
This time, I stocked the 262mm spokes
for the Altegra C60 front wheel,
and for an evil reverse-laced different-diameter purpose,
the C60-HR 262mm might have been better.
The nipples aren't supplied separately in a bag
but come threaded partway onto the spoke threads,
which we separate upon receiving stock.
Still, on the spoke threads
there's a remarkably dark blue
thread-locking compound applied.
Forty-eight spokes weighed 241.0g.
Calculating the spoke weight ratio from here:
241.0÷48÷262÷0.0257＝
0.7456609330...,
so roughly 74.5%.
For C36 spokes this comes to 70.8% or 71.1%,
so I call it about 71%,
but the C36 front wheel is
24mm longer than C60,
so the proportion of #14 plain section at both ends increases,
and these spare spokes have thread-locking compound
applied generously on the threads...
but these factors alone
wouldn't account for a 3% or greater change in spoke weight ratio.
Measuring the flattened butted section thickness with calipers,
C36 spokes are about 1.2mm,
C60 spokes are about 1.3mm.
Also, when passing through the same slot of the spoke truing tool,
the C60 spokes clearly fit tighter,
noticeably different to the touch.
And when I grabbed the butted section midway (not the spoke ends)
with two fingers and flexed the spoke within its elastic range,
the C60 spokes clearly showed
less deformation (stiffer).
If the original round butted spokes
had the same spoke weight ratio,
whether 1.2mm or 1.3mm thick,
the spoke weight ratio wouldn't change.
Out of curiosity I checked the width too,
and both C36 and C60 were 1.9mm, nearly identical.
If this difference is manufacturing tolerance,
then C36 spokes with 74.5% spoke weight ratio
could be in circulation,
but spokes differing 3% in weight ratio
cannot be treated as the same spoke.
If hypothetically the bundle weight of these C60 262mm spokes
with 74.5% spoke weight ratio and 48 spokes
were reduced in number to match a weight at 71% ratio,
the theoretical value would be 45.7 spokes.
Even if we cleaned off all the thread-locking compound
applied to the threads of 48 spokes and collected it,
it couldn't amount to 2.3 spokes' worth of weight.
Whether this is intentional variation or a particular manufacturing batch
that produced thicker spokes, I don't know,
but either way, according to Shimano,
these are spokes called 2.0-1.6-2.0mm.
"Intentionally make different versions with 3.5% different spoke weight ratio
but call them all 2.0-1.6-2.0mm butted"
or "make the same 2.0-1.6-2.0mm aero spokes
and they come out 3.5% different in spoke weight ratio"
↑Either way, they're cutting way too many corners.
284mm, 24 spokes
264mm, 24 spokes
Both images above are CX-RAY,
and I selected lengths close to 286mm and 262mm
that we have in stock.
The 284mm spoke weight ratio is
111.9÷24÷284÷0.0257＝
0.6388036118...,
so around 63.8% to 63.9%.
The 264mm spoke weight ratio is
103.8÷24÷264÷0.0257＝
0.6374542807...,
so 63.7% is fair.
The CX-RAY's #14 plain sections at both ends—
the thread end is constant and the head end varies somewhat,
but for these 264mm and 284mm they were nearly the same.
So the 284mm with relatively longer butted section
should have smaller spoke weight ratio,
but this time it didn't.
Though it's only about 0.2% difference,
which is the level of acceptable tolerance.
One more thing about these C60 spare spokes—
around the spoke-holding crush marking on the thread end
(which I don't use),
there are numerous scuff marks, or paint scratches.
↑This is a spoke extracted from a new C36 wheel,
and shows no such marks.
What's this? Paint so fragile it chips easily when jostled in a bag? Or is this also "individual variation"?
Shimano wheel spokes,
since the beginning—or rather from the original 7700 series on
(except for the 7800 series silver spokes)—
always have paint that chips quickly,
and rust spots soon appear,
so after some years of use the wheels look dirty,
which damages the bike's aesthetics,
and makes me feel these aren't worth the price,
diminishing the joy of ownership.
※A note to parents:
This may be a sign to replace them.
Just as banana peels inevitably turn brown,
maybe if you think of this as "just how it is,"
you wouldn't mind it.
Personally, I do mind it.
Finally. In the image above, on the left is
the new C60 spare spoke we just stocked,
and on the right is a C36 spoke extracted from a new wheel.
You can see the difference in the thread-locking compound darkness.