Another wheel day (and so on...).
This is a continuation from yesterday.
I'm rebuilding the rear wheel that came with the Yamaha e-bike.
I decided to fully rebuild rather than just inspect the front wheel—and I won't pretend I had zero ego in that choice—but when I looked at the rear wheel, a rebuild turned out to be absolutely necessary.
Whoever built this wheel should just give up.
The front wheel was 4-4 laced, but
the rear is 6-6 laced.
I'll mention this now because it matters for what comes next:
the hub flange holes are the same diameter left and right.
There's a frame-end-related component attached to the hub's dropout end.
This plastic part
consists of two pieces joined together,
and the inner piece
is designed to fit onto the center-lock rotor lockring spline.
The outer piece is designed to fit into the left dropout,
and you can see the anodize worn away from the left end—that's from the outer and inner pieces rubbing together while trapping dirt between them—
but it's a shape specific to this rear hub's left end. So if this really is a functional part of the e-bike, it means this bike can only use this wheel, or only wheels built with this rear hub.
If the frame isn't designed with wheel swaps in mind, then no matter how expensive it is, a Yamaha e-bike is just an extension of a mama-chari (commuter bike).
As for wheel centering—
the rim was offset to the right side.
And here's the worst part of this wheel.
Looking at the wheel from the right side (the freewheel side), the next rim hole clockwise from the valve hole is in normal spoke pattern, so it's an anti-freewheel-side spoke.
↑Anti-freewheel-side spoke
It's a bit short—the nipple thread slot is almost worn through—but technically still in acceptable range.
↑The next spoke over—the freewheel-side spoke
The spoke length is way too long.
↑The next one over—anti-freewheel-side
↑The next one over—freewheel-side
...and like this, only the freewheel-side spoke lengths were way too long.
Same rim hole as the previous shot.
It's long enough that it could poke through the rim tape from the back if it dented...
So after disassembling the wheel, I checked the spoke lengths.
With equal-diameter hub flanges left and right,
a non-offset rim, and
the same number of spokes on each side (6-6 laced),
the only factor determining the left-right spoke length difference is the hub's offset.
In the temporary centering, the rim was shifted right, and if I loosened the freewheel-side spokes' nipples to correct the center, the spoke protrusion from the nipples would get slightly better, but the fact that the spokes are too long is unmistakable either way.
At first, I assumed they lazily used the same spoke length throughout when the left and right should differ by about 2mm. But actually, the spoke lengths did differ left and right—accounting for the hub offset properly.
So what was wrong then?
They used the longer spokes meant for the anti-freewheel side on the freewheel side,
and the shorter spokes meant for the freewheel side on the anti-freewheel side.
They built the entire wheel backwards.
That's just incompetence of the lowest order.
Seriously, just quit.
The spoke nipple ends are right in your face as you finish tensioning, and the rim height is obvious—there's no way you wouldn't notice.
I've never seen this before in my own work, so having left and right spokes of different lengths but installing them in reverse... should I call that a 「Yamaha Build」?
If this is the "white crow" against all the black crows, that only proves "at least one white crow exists in this world"—it doesn't prove "there are no other white crows."
If someone proves absolutely that no other white crows exist, I'll take back the dishonor of calling it a Yamaha Build.
I disassembled the wheel.
I'm swapping the left and right spokes, but I'm maintaining the inpoke/outpoke relationship.
While I was at it, since the spokes are #14 plain (meaning they can be cut to any length), I thought about cutting the freewheel side to a 4-spoke lace length and making it 4-6 laced instead. But my own ego won out—I wanted to see what just swapping the spokes would do—so this time I'm rebuilding it as 6-6 laced.
Rebuilt.
Not that it needs saying, but
the center is dead-on.
Looking at the wheel from the right again, next to the valve hole:
Anti-freewheel-side spoke rim hole
Freewheel-side spoke rim hole
Anti-freewheel-side spoke rim hole
Freewheel-side spoke rim hole
Not that it needs saying, but
the spoke lengths are now correct.
Truly just swapped left and right—no machining.
The wheel looks pretty much the same as before, but
I've switched to DT silver aluminum nipples, just like the front wheel.
This is a continuation from yesterday.
I'm rebuilding the rear wheel that came with the Yamaha e-bike.
I decided to fully rebuild rather than just inspect the front wheel—and I won't pretend I had zero ego in that choice—but when I looked at the rear wheel, a rebuild turned out to be absolutely necessary.
Whoever built this wheel should just give up.
The front wheel was 4-4 laced, but
the rear is 6-6 laced.
I'll mention this now because it matters for what comes next:
the hub flange holes are the same diameter left and right.
There's a frame-end-related component attached to the hub's dropout end.
This plastic part
consists of two pieces joined together,
and the inner piece
is designed to fit onto the center-lock rotor lockring spline.
The outer piece is designed to fit into the left dropout,
and you can see the anodize worn away from the left end—that's from the outer and inner pieces rubbing together while trapping dirt between them—
but it's a shape specific to this rear hub's left end. So if this really is a functional part of the e-bike, it means this bike can only use this wheel, or only wheels built with this rear hub.
If the frame isn't designed with wheel swaps in mind, then no matter how expensive it is, a Yamaha e-bike is just an extension of a mama-chari (commuter bike).
As for wheel centering—
the rim was offset to the right side.
And here's the worst part of this wheel.
Looking at the wheel from the right side (the freewheel side), the next rim hole clockwise from the valve hole is in normal spoke pattern, so it's an anti-freewheel-side spoke.
↑Anti-freewheel-side spoke
It's a bit short—the nipple thread slot is almost worn through—but technically still in acceptable range.
↑The next spoke over—the freewheel-side spoke
The spoke length is way too long.
↑The next one over—anti-freewheel-side
↑The next one over—freewheel-side
...and like this, only the freewheel-side spoke lengths were way too long.
Same rim hole as the previous shot.
It's long enough that it could poke through the rim tape from the back if it dented...
So after disassembling the wheel, I checked the spoke lengths.
With equal-diameter hub flanges left and right,
a non-offset rim, and
the same number of spokes on each side (6-6 laced),
the only factor determining the left-right spoke length difference is the hub's offset.
In the temporary centering, the rim was shifted right, and if I loosened the freewheel-side spokes' nipples to correct the center, the spoke protrusion from the nipples would get slightly better, but the fact that the spokes are too long is unmistakable either way.
At first, I assumed they lazily used the same spoke length throughout when the left and right should differ by about 2mm. But actually, the spoke lengths did differ left and right—accounting for the hub offset properly.
So what was wrong then?
They used the longer spokes meant for the anti-freewheel side on the freewheel side,
and the shorter spokes meant for the freewheel side on the anti-freewheel side.
They built the entire wheel backwards.
That's just incompetence of the lowest order.
Seriously, just quit.
The spoke nipple ends are right in your face as you finish tensioning, and the rim height is obvious—there's no way you wouldn't notice.
I've never seen this before in my own work, so having left and right spokes of different lengths but installing them in reverse... should I call that a 「Yamaha Build」?
If this is the "white crow" against all the black crows, that only proves "at least one white crow exists in this world"—it doesn't prove "there are no other white crows."
If someone proves absolutely that no other white crows exist, I'll take back the dishonor of calling it a Yamaha Build.
I disassembled the wheel.
I'm swapping the left and right spokes, but I'm maintaining the inpoke/outpoke relationship.
While I was at it, since the spokes are #14 plain (meaning they can be cut to any length), I thought about cutting the freewheel side to a 4-spoke lace length and making it 4-6 laced instead. But my own ego won out—I wanted to see what just swapping the spokes would do—so this time I'm rebuilding it as 6-6 laced.
Rebuilt.
Not that it needs saying, but
the center is dead-on.
Looking at the wheel from the right again, next to the valve hole:
Anti-freewheel-side spoke rim hole
Freewheel-side spoke rim hole
Anti-freewheel-side spoke rim hole
Freewheel-side spoke rim hole
Not that it needs saying, but
the spoke lengths are now correct.
Truly just swapped left and right—no machining.
The wheel looks pretty much the same as before, but
I've switched to DT silver aluminum nipples, just like the front wheel.