Not building wheels today.
Just doing the prep work for it.
A customer left me with the front and rear wheels from their MTB.
They want the hubs replaced.
Both wheels are built with
silver aerodynamic straight spokes and
black aluminum nipples.
The rim has no holes on the outer perimeter except for the valve hole.
Both front and rear hubs are non-BOOST hubs,
but they want to convert them to BOOST hubs
and change the rear hub's freewheel body from SRAM XD
to Shimano Micro Spline.
Both wheels are 28H. The current XT M8200 series hubs
only come in bent-spoke versions,
but the previous M8100 series has
HB/FH-M8110-BS
(B=BOOST, S=straight spokes),
a hub for straight spokes.
If we use those, we might be able to reuse the current spokes.
Initially, they wanted to keep costs down,
so we were looking at XT hubs for bent spokes with all Campagnolo parts.
More specifically, they said "regular round spokes are fine."
But swapping all spokes on both sides for Campagnolo
costs about the same as replacing just one side with new CX Sprint spokes.
Looking at the original wheel condition—
on both sides, the non-freewheel side felt especially slack.
While spoke tension should be tight, this is way too slack.
Maybe that's why the original builder didn't get asked to rebuild it.
I won't name names, but there was a sticker
next to the valve hole with the builder's name on it.
Oh, how embarrassing.
A different customer who can build wheels
looked at this wheel and said,
"If this were for rim brakes, the shoe would rub for sure."
And they're probably right.
The wheel center was fine.
Now the front wheel.
Again, abnormally slack.
If it were loose from age, you'd see runout or center issues from sagging,
but there's none of that, so it must have been slack from the start.
The temporary center. What the heck?
Actually, there was vinyl tape wrapped around the left hub end.
Spacers were simply added to increase the end width
to match BOOST, which is why the center was way off.
The spacers are 5mm thick,
and I think they were on both sides,
but when I received the wheel, only the left side was
temporarily held with tape.
Checking the center again without the spacers,
the rim was shifted to the left.
About this much.
That's the direction a wheel naturally drifts due to spoke tension,
so it's possible the center was correct when first built.
I put alignment tape on the inner edge of the nipple ends
for the spokes on both sides of the valve hole.
A flaky threadlocker had been applied,
but as you can see, it barely affects the threads—
it just fills the space between nipple threads,
so it only prevents initial loosening somewhat.
Some argue the effect is still there!
But in the image, even 3-4 turns back,
I can twist the nipple between my fingers.
Proper threadlocker that works on the threads
would be too stiff to turn by hand even loosened to that point.
I can't deny that filling the thread pockets
helps prevent fine sand from getting in.
With nipples like Racing Zero or Shamal Ultra,
it seems to delay seizing—
though I'm not sure if the manufacturer intends this.
The hub flange is pass-through on the front hub
and pull-through on the rear,
so I can't remove spokes from the front with the alignment tape on.
Before removing it, I check spoke length relative to the nipple.
Front left side looks like this.
The spoke doesn't quite reach the nipple face,
but it reaches the slot bottom, so it's within spec.
Actually, if I were rebuilding this wheel to improve it,
I'd tighten it another turn and a half,
so the spoke length is about right for that.
Front right side too
looked about the same.
For the rear wheel spokes, I don't need alignment tape.
The nipples are 14mm, and
I can roughly tell from that relationship.
That's because only the rear wheel has
SAPIM (Sapim) spokes on both sides,
and SAPIM spokes have a consistent plain section length,
so I can tell visually.
The front wheel spokes have no branding anywhere—
mystery spokes from who knows where.
If you scroll back through the images,
you'll see that despite similar length to the nipple,
the front left spoke's flat-butted section is under about half the tape,
while the front right spoke's tape is
almost entirely on the plain section.
It's possible the spoke length was modified.
With silver spokes, you can't easily tell
if they've been cut by looking at the cut end,
so front left might have been cut down.
The plain section on front right's threaded end
is long for such a section, suggesting
it's original equipment from the maker. The point is,
unlike universal spokes that might be 300mm but cuttable to 270mm,
aero spokes as a specific length shouldn't have
such a long plain section.
Earlier I called the front wheel's unbranded spokes
"mystery spokes," but separately,
I've discovered this front wheel's builder is
an absolute idiot who doesn't understand spokes or wheels at all.
Front right side: 296mm spokes.
28H with 14 spokes per side, so spoke weight ratio is
76.3÷14÷296÷0.0257=
0.71642... or about 72%.
Rough estimates show SAPIM CX-RAY at 65%,
CX Sprint at 78%, and
the same for DT Aerolite (65%) and Aerocomp (78%),
but major manufacturers with stable supply
don't make aero spokes at 72% weight ratio,
so I can't use CX-RAY or CX Sprint for repairs.
A 6-7% difference isn't acceptable to mix in one wheel.
The front wheel spokes are
square aero shape on both sides, by the way.
Square aero has a flat-butted section with a near-rectangular cross-section;
elliptic aero has pointed ends with a near-elliptical section.
CX-RAY, for example, is elliptic aero.
Front right side: 295mm spokes.
Spoke weight ratio is 71.0÷14÷295÷0.0257=
0.66892... or about 67%.
At this weight ratio, even with different shape,
I could barely mix in CX-RAY for repairs.
But that's not the important part.
The real question is: why does a 1mm length difference
result in a 5% weight ratio difference between bundles of 14 spokes?
Front right weighs 76.3g, so one spoke is 5.45g.
Removing that (13 spokes) gives 70.85g,
almost the same as front left's 14 spokes.
If both sides truly had identical spokes,
there's no way a 14-spoke bundle would differ by one spoke's weight.
Measuring with calipers, I found
front right spokes are 2.2×1.0mm
and front left spokes are 2.0×1.0mm.
Those aware already see the problem:
this wheel is built in reverse different-diameter fashion.
A 4.75% left-right difference isn't same-diameter building.
It's obviously not the builder's taste
(I'd love to hear why they'd deliberately favor uneven spoke tension)
but sheer incompetence—they didn't know spokes,
didn't measure, and like an idiot,
thought they had matching spokes when they didn't.
If it had accidentally been left-right different-diameter,
I'd have thought it intentional design and praised them.
Rear right side: 294mm CX-RAY.
Spoke weight ratio is 67.2÷14÷294÷0.0257=
0.63527... or about 64%.
Rear left side: 296mm CX-RAY.
Spoke weight ratio is 68.3÷14÷296÷0.0257=
0.64130... or about 64%.
Mystery spokes (left) versus CX-RAY (right) at the spoke head.
Even CX-RAY varies slightly in plain section length at the head
compared to the threaded end,
which affects spoke weight ratio, presumably from lighter flat-butted sections.
This front right spoke came in at 66.7% weight ratio.
If its head-end plain section were as short as SAPIM's,
it would be around 65%.
I use 65% as a rough estimate for CX-RAY weight ratio
and 64.5% for precise calculation,
but that's for bent spokes.
From measurement scope, excluded volume is larger
with bent spokes than straight spokes,
so straight spokes tend to show lower weight ratio.
CX-RAY lower limits of 63.5% on bent spokes mean
straight spokes could be in the 62% range.
SAPIM branding.
If the front being reverse different-diameter
meant "they tried for positive different-diameter and failed,"
the rear's larger dish wouldn't make sense
to build as same-diameter with CX-RAY,
so again, the conclusion is just careless spoke inventory
and an idiot builder.
I'm glad I developed the habit of checking
spoke weight ratio on all mystery spokes.
Almost became one of the idiots myself.
I haven't built wheels in this post,
but this prep work—
though usually unwritten—
happens constantly.
Ah, the original goal:
"If spokes are reusable, source M8100 straight-spoke hubs;
if not, use M8200 general spokes hubs"
looks like the former works.
New front: old front-left becomes front-right,
old rear-right becomes front-left,
new rear-right as new CX Sprint,
rear-left stays the same.
This gives left/right spoke weight ratios of
front: 71.0 (measured) / 63.5 (measured)
rear: 64.1 (measured) / 78 (estimate)
making a nice left-right different-diameter build.
Hub retail prices:
HB/FH-M8110-BS:
Front ¥13,599
Rear ¥21,814
Total ¥35,413
HB/FH-M8210-B:
Front ¥12,058
Rear ¥28,057
Total ¥40,115
Front hub prices flip, but the combined total is higher for M8200 series.
Since M8200 requires all new spokes,
using M8100 straight-spoke hubs to reuse spokes as much as possible
is better both for cost control and efficiency.
Just doing the prep work for it.
A customer left me with the front and rear wheels from their MTB.
They want the hubs replaced.
Both wheels are built with
silver aerodynamic straight spokes and
black aluminum nipples.
The rim has no holes on the outer perimeter except for the valve hole.
Both front and rear hubs are non-BOOST hubs,
but they want to convert them to BOOST hubs
and change the rear hub's freewheel body from SRAM XD
to Shimano Micro Spline.
Both wheels are 28H. The current XT M8200 series hubs
only come in bent-spoke versions,
but the previous M8100 series has
HB/FH-M8110-BS
(B=BOOST, S=straight spokes),
a hub for straight spokes.
If we use those, we might be able to reuse the current spokes.
Initially, they wanted to keep costs down,
so we were looking at XT hubs for bent spokes with all Campagnolo parts.
More specifically, they said "regular round spokes are fine."
But swapping all spokes on both sides for Campagnolo
costs about the same as replacing just one side with new CX Sprint spokes.
Looking at the original wheel condition—
on both sides, the non-freewheel side felt especially slack.
While spoke tension should be tight, this is way too slack.
Maybe that's why the original builder didn't get asked to rebuild it.
I won't name names, but there was a sticker
next to the valve hole with the builder's name on it.
Oh, how embarrassing.
A different customer who can build wheels
looked at this wheel and said,
"If this were for rim brakes, the shoe would rub for sure."
And they're probably right.
The wheel center was fine.
Now the front wheel.
Again, abnormally slack.
If it were loose from age, you'd see runout or center issues from sagging,
but there's none of that, so it must have been slack from the start.
The temporary center. What the heck?
Actually, there was vinyl tape wrapped around the left hub end.
Spacers were simply added to increase the end width
to match BOOST, which is why the center was way off.
The spacers are 5mm thick,
and I think they were on both sides,
but when I received the wheel, only the left side was
temporarily held with tape.
Checking the center again without the spacers,
the rim was shifted to the left.
About this much.
That's the direction a wheel naturally drifts due to spoke tension,
so it's possible the center was correct when first built.
I put alignment tape on the inner edge of the nipple ends
for the spokes on both sides of the valve hole.
A flaky threadlocker had been applied,
but as you can see, it barely affects the threads—
it just fills the space between nipple threads,
so it only prevents initial loosening somewhat.
Some argue the effect is still there!
But in the image, even 3-4 turns back,
I can twist the nipple between my fingers.
Proper threadlocker that works on the threads
would be too stiff to turn by hand even loosened to that point.
I can't deny that filling the thread pockets
helps prevent fine sand from getting in.
With nipples like Racing Zero or Shamal Ultra,
it seems to delay seizing—
though I'm not sure if the manufacturer intends this.
The hub flange is pass-through on the front hub
and pull-through on the rear,
so I can't remove spokes from the front with the alignment tape on.
Before removing it, I check spoke length relative to the nipple.
Front left side looks like this.
The spoke doesn't quite reach the nipple face,
but it reaches the slot bottom, so it's within spec.
Actually, if I were rebuilding this wheel to improve it,
I'd tighten it another turn and a half,
so the spoke length is about right for that.
Front right side too
looked about the same.
For the rear wheel spokes, I don't need alignment tape.
The nipples are 14mm, and
I can roughly tell from that relationship.
That's because only the rear wheel has
SAPIM (Sapim) spokes on both sides,
and SAPIM spokes have a consistent plain section length,
so I can tell visually.
The front wheel spokes have no branding anywhere—
mystery spokes from who knows where.
If you scroll back through the images,
you'll see that despite similar length to the nipple,
the front left spoke's flat-butted section is under about half the tape,
while the front right spoke's tape is
almost entirely on the plain section.
It's possible the spoke length was modified.
With silver spokes, you can't easily tell
if they've been cut by looking at the cut end,
so front left might have been cut down.
The plain section on front right's threaded end
is long for such a section, suggesting
it's original equipment from the maker. The point is,
unlike universal spokes that might be 300mm but cuttable to 270mm,
aero spokes as a specific length shouldn't have
such a long plain section.
Earlier I called the front wheel's unbranded spokes
"mystery spokes," but separately,
I've discovered this front wheel's builder is
an absolute idiot who doesn't understand spokes or wheels at all.
Front right side: 296mm spokes.
28H with 14 spokes per side, so spoke weight ratio is
76.3÷14÷296÷0.0257=
0.71642... or about 72%.
Rough estimates show SAPIM CX-RAY at 65%,
CX Sprint at 78%, and
the same for DT Aerolite (65%) and Aerocomp (78%),
but major manufacturers with stable supply
don't make aero spokes at 72% weight ratio,
so I can't use CX-RAY or CX Sprint for repairs.
A 6-7% difference isn't acceptable to mix in one wheel.
The front wheel spokes are
square aero shape on both sides, by the way.
Square aero has a flat-butted section with a near-rectangular cross-section;
elliptic aero has pointed ends with a near-elliptical section.
CX-RAY, for example, is elliptic aero.
Front right side: 295mm spokes.
Spoke weight ratio is 71.0÷14÷295÷0.0257=
0.66892... or about 67%.
At this weight ratio, even with different shape,
I could barely mix in CX-RAY for repairs.
But that's not the important part.
The real question is: why does a 1mm length difference
result in a 5% weight ratio difference between bundles of 14 spokes?
Front right weighs 76.3g, so one spoke is 5.45g.
Removing that (13 spokes) gives 70.85g,
almost the same as front left's 14 spokes.
If both sides truly had identical spokes,
there's no way a 14-spoke bundle would differ by one spoke's weight.
Measuring with calipers, I found
front right spokes are 2.2×1.0mm
and front left spokes are 2.0×1.0mm.
Those aware already see the problem:
this wheel is built in reverse different-diameter fashion.
A 4.75% left-right difference isn't same-diameter building.
It's obviously not the builder's taste
(I'd love to hear why they'd deliberately favor uneven spoke tension)
but sheer incompetence—they didn't know spokes,
didn't measure, and like an idiot,
thought they had matching spokes when they didn't.
If it had accidentally been left-right different-diameter,
I'd have thought it intentional design and praised them.
Rear right side: 294mm CX-RAY.
Spoke weight ratio is 67.2÷14÷294÷0.0257=
0.63527... or about 64%.
Rear left side: 296mm CX-RAY.
Spoke weight ratio is 68.3÷14÷296÷0.0257=
0.64130... or about 64%.
Mystery spokes (left) versus CX-RAY (right) at the spoke head.
Even CX-RAY varies slightly in plain section length at the head
compared to the threaded end,
which affects spoke weight ratio, presumably from lighter flat-butted sections.
This front right spoke came in at 66.7% weight ratio.
If its head-end plain section were as short as SAPIM's,
it would be around 65%.
I use 65% as a rough estimate for CX-RAY weight ratio
and 64.5% for precise calculation,
but that's for bent spokes.
From measurement scope, excluded volume is larger
with bent spokes than straight spokes,
so straight spokes tend to show lower weight ratio.
CX-RAY lower limits of 63.5% on bent spokes mean
straight spokes could be in the 62% range.
SAPIM branding.
If the front being reverse different-diameter
meant "they tried for positive different-diameter and failed,"
the rear's larger dish wouldn't make sense
to build as same-diameter with CX-RAY,
so again, the conclusion is just careless spoke inventory
and an idiot builder.
I'm glad I developed the habit of checking
spoke weight ratio on all mystery spokes.
Almost became one of the idiots myself.
I haven't built wheels in this post,
but this prep work—
though usually unwritten—
happens constantly.
Ah, the original goal:
"If spokes are reusable, source M8100 straight-spoke hubs;
if not, use M8200 general spokes hubs"
looks like the former works.
New front: old front-left becomes front-right,
old rear-right becomes front-left,
new rear-right as new CX Sprint,
rear-left stays the same.
This gives left/right spoke weight ratios of
front: 71.0 (measured) / 63.5 (measured)
rear: 64.1 (measured) / 78 (estimate)
making a nice left-right different-diameter build.
Hub retail prices:
HB/FH-M8110-BS:
Front ¥13,599
Rear ¥21,814
Total ¥35,413
HB/FH-M8210-B:
Front ¥12,058
Rear ¥28,057
Total ¥40,115
Front hub prices flip, but the combined total is higher for M8200 series.
Since M8200 requires all new spokes,
using M8100 straight-spoke hubs to reuse spokes as much as possible
is better both for cost control and efficiency.