Another wheel day (and so on).
I built a replacement wheel for the WH-7900-C24.
A customer had a major crash on a descent the other day,
and both bike and wheel took damage.
The front wheel was completely potato-chip warped,
so we decided to build a new one.
I wanted to reuse the hub,
but there's no reasonably priced 16H aluminum rim available, so
I built the front wheel of nomu lab wheel #5 using a Reefhub 20H with full competition outpoke radial lacing.
↑The rear wheel had a runout at one spot that just wouldn't come out,
so I'm rebuilding that one too with an XR200 rim.
If I reuse the hub,
it becomes absolutely impossible to adapt to 11-speed (→here),
but since the bike this is going on doesn't seem likely to go 11-speed anytime soon
(the frame and everything else survived intact),
I decided to reuse it.
Update:
I received a comment saying that an 11-speed sprocket can be used with a 10-speed freebody.
Thank you for that.
However, the point remains that switching this rear hub to an 11-speed compatible one is impossible.
Also, that third-party special sprocket has pretty terrible shifting performance.
Built.
The spokes are Sapim Leader straight gauge.
At 2.0mm plain,
the spoke weight ratio as I talk about it on this blog is 100%.
The rear wheel spokes on the WH-9000-C24 are aero spokes equivalent to 2.0-1.5-2.0 on both sides,
but on the WH-7900-C24, only the drive side
has aero spokes equivalent to 2.0-1.8-2.0,
making it asymmetric diameter lacing.
Plus the C24 is an offset rim.
With a non-offset rim and symmetric diameter lacing,
and originally with 4-4 lacing meaning the same number of spokes both sides,
the non-drive side inevitably comes out a bit loose.
Sometimes when I build a "normal wheel" like this, I'm amazed.
↑This is before disassembling the wheel being replaced,
but Shimano wheels don't cross-lace the final crossing.
I can imagine why they don't,
so I don't have a strongly negative view on this point.
I do hate reverse Italian lacing, though.
Not crossing the last one appears to be because the
lateral positions where the spokes come out are different left and right,
but actually when building a wheel with a normal hub,
the difference in lateral position between inpoke and outpoke—offset by the flange thickness—
isn't all that different from this.
So this time I tried crossing it.
Also, Shimano wheels align the hub shell phase visible from the valve hole precisely with
the WH-○○○○ marking on the opposite side 180° from the SHIMANO or DURA-ACE logo,
but on this wheel I set the phase to what I do when building with a Duraace hub—
where the DURA-ACE logo is visible.
I'm not doing any spoke soldering on the non-drive side.
Whether to do it or not is left to my discretion, but it's not because it's a hassle.
I soldered two of the five intersections, but then unwound them again.
You can undo them before soldering.
I noticed after disassembling the wheel that
the rear rim had a buckle in one spot.
This seems to be the cause of that "runout that just wouldn't come out."
The front wheel is discarded entirely,
but with the rear wheel I got just the rim, so I know its actual weight.
Since the buckle's effect on weight appears to be extremely minor,
this rim's weight in this condition
could serve as a sample for determining the WH-7900-C24 WO rear rim weight.
Not that I'm going to tell anyone.
↑wow, this guy's got a bad attitude
○Please○ wait!
○Crab laser image ○ Please ○ view!
↑No way・・・huh？
＜Sad News＞Actually, after a forced firmware update the other day,
the crab laser has been acting strange.
The sharpness it once had is nowhere to be seen.
It's unclear whether it can be restored.
Completely unrelated to this situation,
regarding the previous issue about simultaneously connecting junction A (upper JC) and the display
with electric shifting components,
I received a comment saying:
"Di2 stopped working after a firmware update.
(I wasn't sure if the firmware update was the cause.)"
I built a replacement wheel for the WH-7900-C24.
A customer had a major crash on a descent the other day,
and both bike and wheel took damage.
The front wheel was completely potato-chip warped,
so we decided to build a new one.
I wanted to reuse the hub,
but there's no reasonably priced 16H aluminum rim available, so
I built the front wheel of nomu lab wheel #5 using a Reefhub 20H with full competition outpoke radial lacing.
↑The rear wheel had a runout at one spot that just wouldn't come out,
so I'm rebuilding that one too with an XR200 rim.
If I reuse the hub,
it becomes absolutely impossible to adapt to 11-speed (→here),
but since the bike this is going on doesn't seem likely to go 11-speed anytime soon
(the frame and everything else survived intact),
I decided to reuse it.
Update:
I received a comment saying that an 11-speed sprocket can be used with a 10-speed freebody.
Thank you for that.
However, the point remains that switching this rear hub to an 11-speed compatible one is impossible.
Also, that third-party special sprocket has pretty terrible shifting performance.
Built.
The spokes are Sapim Leader straight gauge.
At 2.0mm plain,
the spoke weight ratio as I talk about it on this blog is 100%.
The rear wheel spokes on the WH-9000-C24 are aero spokes equivalent to 2.0-1.5-2.0 on both sides,
but on the WH-7900-C24, only the drive side
has aero spokes equivalent to 2.0-1.8-2.0,
making it asymmetric diameter lacing.
Plus the C24 is an offset rim.
With a non-offset rim and symmetric diameter lacing,
and originally with 4-4 lacing meaning the same number of spokes both sides,
the non-drive side inevitably comes out a bit loose.
Sometimes when I build a "normal wheel" like this, I'm amazed.
↑This is before disassembling the wheel being replaced,
but Shimano wheels don't cross-lace the final crossing.
I can imagine why they don't,
so I don't have a strongly negative view on this point.
I do hate reverse Italian lacing, though.
Not crossing the last one appears to be because the
lateral positions where the spokes come out are different left and right,
but actually when building a wheel with a normal hub,
the difference in lateral position between inpoke and outpoke—offset by the flange thickness—
isn't all that different from this.
So this time I tried crossing it.
Also, Shimano wheels align the hub shell phase visible from the valve hole precisely with
the WH-○○○○ marking on the opposite side 180° from the SHIMANO or DURA-ACE logo,
but on this wheel I set the phase to what I do when building with a Duraace hub—
where the DURA-ACE logo is visible.
I'm not doing any spoke soldering on the non-drive side.
Whether to do it or not is left to my discretion, but it's not because it's a hassle.
I soldered two of the five intersections, but then unwound them again.
You can undo them before soldering.
I noticed after disassembling the wheel that
the rear rim had a buckle in one spot.
This seems to be the cause of that "runout that just wouldn't come out."
The front wheel is discarded entirely,
but with the rear wheel I got just the rim, so I know its actual weight.
Since the buckle's effect on weight appears to be extremely minor,
this rim's weight in this condition
could serve as a sample for determining the WH-7900-C24 WO rear rim weight.
Not that I'm going to tell anyone.
↑wow, this guy's got a bad attitude
○Please○ wait!
○Crab laser image ○ Please ○ view!
↑No way・・・huh？
＜Sad News＞Actually, after a forced firmware update the other day,
the crab laser has been acting strange.
The sharpness it once had is nowhere to be seen.
It's unclear whether it can be restored.
Completely unrelated to this situation,
regarding the previous issue about simultaneously connecting junction A (upper JC) and the display
with electric shifting components,
I received a comment saying:
"Di2 stopped working after a firmware update.
(I wasn't sure if the firmware update was the cause.)"