More wheels today (and so on).
Continuing from before.
Built the rear wheel with a Super Champion wooden rim.
Campagnolo Earth Mark Record
120mm width boss freewheel large flange hub 36H
NJS keirin 15-speed Aerostar Bright
88-Italian lacing, no binding.
The overlock nut dimension measured
120.5mm width in actual measurement,
so with the nominally 120mm width hub,
the boss gear to attach appears to be 5S or 6S,
which really helped out.
↑Hub before assembly
From the edge of the sprocket threads
to the right end is clearly quite short.
The flange width (outer to outer) measured 57.3mm on my caliper.
Here, I'll compare the hub's spoke tension asymmetry
with various Shimano hubs.
The hubs I'm comparing are
Record Large Flange Quick Release (LFQR) 120mm width,
Dura-Ace track single-thread right side HB-7600-R-S,
disc front hub HB-RS770
(I've flipped left and right to compare asymmetry),
and the FH-9000, the last single-unit sold Dura-Ace grade
11S freewheel body hub. Four in total.
I reference Shimano hubs because
their published hub dimensions are precise,
and my interpretation of flange width matches theirs—outer to outer,
the measurement when you clamp the flange with calipers
(many manufacturers publish flange width as C-C dimension).
In other words, the spoke length I calculate
is the true spoke length,
and for the inverted spoke, the threads advance further into the nipple,
but I absorb that difference in the redundancy
of the nipple thread length.
Radial front wheels are typically built as inverted-radial lacing
but the spoke length is calculated from true spoke length,
so if I need to cut spokes, I sometimes make them
0.5mm shorter than the calculated length.
If the calculated length is 284.52mm →
rounded to 285mm, I'll use a ready-made 285mm spoke as-is,
but if cutting from a 288mm spoke,
I'll cut to 284.5mm.
For the Record hub I added my actual measurements of left/right flange widths,
for Shimano hubs I added their nominal flange widths and offset amounts.
Shimano's flange width information lets you calculate
left/right flange widths with "flange width/2 ± offset amount".
I keep saying they should publish the left/right flange widths directly
instead of making people calculate them,
but gaining this perspective on what Shimano calls "offset amount"
might be useful.
Since there's a difference in information types here,
I added the Shimano-equivalent values for the Record hub
and the left/right flange widths for Shimano hubs.
This reveals characteristics like:
"The Record 120mm has less offset than a single-thread fixed-gear hub"
"The Record 120mm right flange width matches
the disc front hub bracket-side flange width"
and such.
For the Dura-Ace track
large flange hub HB-7600 and
small flange hub HB-7710,
with front, double-thread rear, and single-thread rear—
six hub types total—if built 8-cross with the current
one-make Araya 16B Gold 36H keirin rim,
you get eight different spoke lengths:
front left/right, double-thread left/right,
single-thread right, single-thread left.
In my spoke length calculation,
the shortest is 304.72mm and the longest 306.52mm,
rounding to 305–307mm in 1mm units.
But current keirin spokes come only in 305mm length
based on Hoshi 15-number round-butted or
aero-butted.
What I'm getting at is:
this Record 120mm hub has as little spoke tension asymmetry
as a fixed-gear single-thread hub,
so you don't need left/right different-diameter
or left/right different-gauge lacing.
I added "the percentage of right flange width
relative to total left/right flange width".
If this were 50% and the left/right flange diameters matched,
the theoretical spoke tension would be equal too (front hub state).
From this perspective, the Record 120mm also shows
values similar to a single-thread fixed-gear hub.
Unavoidably,
the FH-9000 has such narrow right flange width—under 19mm—
that asymmetry becomes quite severe.
The 9-speed Dura-Ace hub FH-7700
had flange widths of 21.1mm right and 36.9mm left,
which in current Shimano terms is 58.0mm total width
with 7.9mm offset, giving the right flange
a 36.3% ratio.
Both FH-7700 and FH-9000 are high-low flange hubs
with 1mm diameter difference left to right,
but this isn't a significant enough difference to affect
wheel characteristics.
If this wooden rim project had used the FH-9000,
even maxing out tension on the freewheel side
to the rim's limit, the non-freewheel side would immediately
go slack at low tension.
I'd have to employ left/right different-diameter different-gauge lacing,
but even then I'm not sure it'd work out.
So having the Record 120mm for this job was extremely fortunate.
As I've noted, this wheel requires tension high enough
that the wooden rim holes don't break,
yet not so high that spokes loosen later.
Spoke tension variance becomes narrower
the higher the tension goes.
The three blue lines in the diagram above show,
for each tension level, the highest spoke tension
among those on the high-tension flange
when wheel building is complete,
and the minimum tension relative to these is
↑varies like this.
Not exceeding the upper line is an absolute requirement,
but being too conservative and loose means
dropping below the lower line.
With a hub having small asymmetry—
small offset in Shimano terms,
high percentage of right flange in total width—
you can tighten the spacing between these variance bounds
by reducing the drop from maximum tension.
Normally, when I build front and rear wheels
on the same rim with the same spoke count,
I aim for light perimeter weight on the drive wheel,
using the lighter rim on the rear.
Sometimes the difference is so extreme that
aluminum nipple weight becomes 0g on rear only,
or TPU tube weight becomes 0g on rear only.
But this time I used the heavier rim on the rear
expecting better buckling resistance.
Since wooden rims vary widely,
I can't claim this rim's weight is typical of wooden rims—
same as with aluminum or carbon—
but I'm not going to tell you this rim's measured weight.
↑man that's not cool
Sorry for the wait!
Please look at these photos!
↑Noooo stop it!
Continuing from before.
Built the rear wheel with a Super Champion wooden rim.
Campagnolo Earth Mark Record
120mm width boss freewheel large flange hub 36H
NJS keirin 15-speed Aerostar Bright
88-Italian lacing, no binding.
The overlock nut dimension measured
120.5mm width in actual measurement,
so with the nominally 120mm width hub,
the boss gear to attach appears to be 5S or 6S,
which really helped out.
↑Hub before assembly
From the edge of the sprocket threads
to the right end is clearly quite short.
The flange width (outer to outer) measured 57.3mm on my caliper.
Here, I'll compare the hub's spoke tension asymmetry
with various Shimano hubs.
The hubs I'm comparing are
Record Large Flange Quick Release (LFQR) 120mm width,
Dura-Ace track single-thread right side HB-7600-R-S,
disc front hub HB-RS770
(I've flipped left and right to compare asymmetry),
and the FH-9000, the last single-unit sold Dura-Ace grade
11S freewheel body hub. Four in total.
I reference Shimano hubs because
their published hub dimensions are precise,
and my interpretation of flange width matches theirs—outer to outer,
the measurement when you clamp the flange with calipers
(many manufacturers publish flange width as C-C dimension).
In other words, the spoke length I calculate
is the true spoke length,
and for the inverted spoke, the threads advance further into the nipple,
but I absorb that difference in the redundancy
of the nipple thread length.
Radial front wheels are typically built as inverted-radial lacing
but the spoke length is calculated from true spoke length,
so if I need to cut spokes, I sometimes make them
0.5mm shorter than the calculated length.
If the calculated length is 284.52mm →
rounded to 285mm, I'll use a ready-made 285mm spoke as-is,
but if cutting from a 288mm spoke,
I'll cut to 284.5mm.
For the Record hub I added my actual measurements of left/right flange widths,
for Shimano hubs I added their nominal flange widths and offset amounts.
Shimano's flange width information lets you calculate
left/right flange widths with "flange width/2 ± offset amount".
I keep saying they should publish the left/right flange widths directly
instead of making people calculate them,
but gaining this perspective on what Shimano calls "offset amount"
might be useful.
Since there's a difference in information types here,
I added the Shimano-equivalent values for the Record hub
and the left/right flange widths for Shimano hubs.
This reveals characteristics like:
"The Record 120mm has less offset than a single-thread fixed-gear hub"
"The Record 120mm right flange width matches
the disc front hub bracket-side flange width"
and such.
For the Dura-Ace track
large flange hub HB-7600 and
small flange hub HB-7710,
with front, double-thread rear, and single-thread rear—
six hub types total—if built 8-cross with the current
one-make Araya 16B Gold 36H keirin rim,
you get eight different spoke lengths:
front left/right, double-thread left/right,
single-thread right, single-thread left.
In my spoke length calculation,
the shortest is 304.72mm and the longest 306.52mm,
rounding to 305–307mm in 1mm units.
But current keirin spokes come only in 305mm length
based on Hoshi 15-number round-butted or
aero-butted.
What I'm getting at is:
this Record 120mm hub has as little spoke tension asymmetry
as a fixed-gear single-thread hub,
so you don't need left/right different-diameter
or left/right different-gauge lacing.
I added "the percentage of right flange width
relative to total left/right flange width".
If this were 50% and the left/right flange diameters matched,
the theoretical spoke tension would be equal too (front hub state).
From this perspective, the Record 120mm also shows
values similar to a single-thread fixed-gear hub.
Unavoidably,
the FH-9000 has such narrow right flange width—under 19mm—
that asymmetry becomes quite severe.
The 9-speed Dura-Ace hub FH-7700
had flange widths of 21.1mm right and 36.9mm left,
which in current Shimano terms is 58.0mm total width
with 7.9mm offset, giving the right flange
a 36.3% ratio.
Both FH-7700 and FH-9000 are high-low flange hubs
with 1mm diameter difference left to right,
but this isn't a significant enough difference to affect
wheel characteristics.
If this wooden rim project had used the FH-9000,
even maxing out tension on the freewheel side
to the rim's limit, the non-freewheel side would immediately
go slack at low tension.
I'd have to employ left/right different-diameter different-gauge lacing,
but even then I'm not sure it'd work out.
So having the Record 120mm for this job was extremely fortunate.
As I've noted, this wheel requires tension high enough
that the wooden rim holes don't break,
yet not so high that spokes loosen later.
Spoke tension variance becomes narrower
the higher the tension goes.
The three blue lines in the diagram above show,
for each tension level, the highest spoke tension
among those on the high-tension flange
when wheel building is complete,
and the minimum tension relative to these is
↑varies like this.
Not exceeding the upper line is an absolute requirement,
but being too conservative and loose means
dropping below the lower line.
With a hub having small asymmetry—
small offset in Shimano terms,
high percentage of right flange in total width—
you can tighten the spacing between these variance bounds
by reducing the drop from maximum tension.
Normally, when I build front and rear wheels
on the same rim with the same spoke count,
I aim for light perimeter weight on the drive wheel,
using the lighter rim on the rear.
Sometimes the difference is so extreme that
aluminum nipple weight becomes 0g on rear only,
or TPU tube weight becomes 0g on rear only.
But this time I used the heavier rim on the rear
expecting better buckling resistance.
Since wooden rims vary widely,
I can't claim this rim's weight is typical of wooden rims—
same as with aluminum or carbon—
but I'm not going to tell you this rim's measured weight.
↑man that's not cool
Sorry for the wait!
Please look at these photos!
↑Noooo stop it!