Another day with wheels (and so on).
A customer dropped off both front and rear wheels from a Shimano Ultegra
C36 wheelset with us.
They said the wheels feel loose, so they want them rebuilt.
Today I'm rebuilding the rear wheel.
The front wheel is 12+12 on each side, 24H total,
but the rear wheel is 8+16, also 24H.
With Roval's 24H rear wheels,
the rim holes for the left-side spokes in the right-right-left XI lacing pattern
are clearly offset to one side,
so rebuilding to an equal-sided lacing isn't possible.
However, current Shimano rear wheels with right-left-right Ж (Cyrillic ZH) lacing
have all rim holes centered,
so equal-sided lacing rebuilding is possible.
The directionality of the rim holes becomes apparent
through the feel when building the wheel.
Using blue for freebody-side spokes and red for non-freebody-side spokes,
with arrows pointing up for freebody side and down for non-freebody side,
the pattern ↗↓↖ repeats 8 times for 24H.
Even if we represent that the non-freebody side is 0-cross lacing
(deviating from radial) with diagonal arrows rather than dismissing it as trivial,
the pattern becomes ↗↘↖↗↙↖ repeating 4 times for 24H,
but it's reasonable to interpret this as essentially radial lacing.
Comparing half a wheel of Shimano's Ж lacing with half a wheel of equal-sided lacing:
↗↓↖↗↓↖↗↓↖↗↓↖ (Shimano Ж lacing)
↘↗↙↖↘↗↙↖↘↗↙↖ (equal-sided lacing)
Where the arrow directions don't match up,
you're working against the rim hole directionality.
However, it's not strong enough to prevent the wheel from being built.
I photographed the inside of a rim hole without turning any nipples at all.
It's hard to see like this, so
I carefully disassembled the wheel,
and pushed an unused nipple out from the rim hole next to the valve hole
so you could see it.
About 5 threads of the spoke are sticking out beyond the nipple,
and while the nipple is longer than a generic one
(especially the part beyond where it contacts the rim hole)
↑the spoke thread length is
(I've laid Sapim's silver CX-RAY next to it for comparison)
the same as a generic spoke.
The nipple's threaded section is shifted toward the outer circumference,
so it's not like the periodontal pockets are particularly deep,
which makes it obvious that the spoke length is too long.
The problem with spokes being too long is that
since the threads are nearly fully engaged,
there's limited room for further tightening... which is fine
(with the suspension setup, tightening more won't change much anyway),
but the real issue is
the increased risk of spoke breakage at the thread start point.
It's built.
Revo disc hub, 24H, black half-comp 1.46 JIS lacing.
I'll do the spoking later.
Essentially, I took the rim part from Nomo Lab Wheel No. 8
and swapped it onto the Ultegra wheelset's rim.
I'm using DT generic 12mm black aluminum nipples.
A customer dropped off both front and rear wheels from a Shimano Ultegra
C36 wheelset with us.
They said the wheels feel loose, so they want them rebuilt.
Today I'm rebuilding the rear wheel.
The front wheel is 12+12 on each side, 24H total,
but the rear wheel is 8+16, also 24H.
With Roval's 24H rear wheels,
the rim holes for the left-side spokes in the right-right-left XI lacing pattern
are clearly offset to one side,
so rebuilding to an equal-sided lacing isn't possible.
However, current Shimano rear wheels with right-left-right Ж (Cyrillic ZH) lacing
have all rim holes centered,
so equal-sided lacing rebuilding is possible.
The directionality of the rim holes becomes apparent
through the feel when building the wheel.
Using blue for freebody-side spokes and red for non-freebody-side spokes,
with arrows pointing up for freebody side and down for non-freebody side,
the pattern ↗↓↖ repeats 8 times for 24H.
Even if we represent that the non-freebody side is 0-cross lacing
(deviating from radial) with diagonal arrows rather than dismissing it as trivial,
the pattern becomes ↗↘↖↗↙↖ repeating 4 times for 24H,
but it's reasonable to interpret this as essentially radial lacing.
Comparing half a wheel of Shimano's Ж lacing with half a wheel of equal-sided lacing:
↗↓↖↗↓↖↗↓↖↗↓↖ (Shimano Ж lacing)
↘↗↙↖↘↗↙↖↘↗↙↖ (equal-sided lacing)
Where the arrow directions don't match up,
you're working against the rim hole directionality.
However, it's not strong enough to prevent the wheel from being built.
I photographed the inside of a rim hole without turning any nipples at all.
It's hard to see like this, so
I carefully disassembled the wheel,
and pushed an unused nipple out from the rim hole next to the valve hole
so you could see it.
About 5 threads of the spoke are sticking out beyond the nipple,
and while the nipple is longer than a generic one
(especially the part beyond where it contacts the rim hole)
↑the spoke thread length is
(I've laid Sapim's silver CX-RAY next to it for comparison)
the same as a generic spoke.
The nipple's threaded section is shifted toward the outer circumference,
so it's not like the periodontal pockets are particularly deep,
which makes it obvious that the spoke length is too long.
The problem with spokes being too long is that
since the threads are nearly fully engaged,
there's limited room for further tightening... which is fine
(with the suspension setup, tightening more won't change much anyway),
but the real issue is
the increased risk of spoke breakage at the thread start point.
It's built.
Revo disc hub, 24H, black half-comp 1.46 JIS lacing.
I'll do the spoking later.
Essentially, I took the rim part from Nomo Lab Wheel No. 8
and swapped it onto the Ultegra wheelset's rim.
I'm using DT generic 12mm black aluminum nipples.