A customer brought in a Racing Zero rear wheel for me to work on.
Starting with the front wheel.
They wanted an overhaul, but both the front and rear hubs had play in them.
The front wheel condition was so bad I couldn't imagine riding it like that,
so maybe they started taking it apart but decided not to touch it themselves after all.
Yep, this is a new shaft waiting to explode.
I tighten the right end first, then use the right 14mm grip width and
loosen the left end with the 5mm Allen key hole on the left side.
The cone pressed onto the hub was the "black" type.
For the steel balls and USB-use black ball races,
they were supposedly switched to silver races back in the day,
but even with the new front hubs that have two fewer bearings than the old ones,
I'm seeing black specs occasionally now.
So apparently they're deliberately manufacturing black specs anew for some reason.
Since the black and silver have the same part numbers, the manufacturer treats them as "the same thing,"
but based on my experience, durability—especially the rust creep resistance for USB use—is noticeably lower with black,
(and I suspect that's why the manufacturer switched to silver back then),
so I can't understand the reason for going back to black ball races.
Since there's no rust creep and the parts are pricey, I'm not replacing them this time.
Also, for some reason the ball cup is silver spec.
I applied DT Spoke Freeze,
and tightened it up securely with the 14mm grip width and the 5mm Allen key on the right end.
Going forward, if I loosen it with the 5mm Allen keys on both ends,
the right end will almost certainly never loosen first.
I didn't check the preliminary center before overhauling the hub,
but after the overhaul there was a slight offset.
I corrected the slight lateral runout and center offset.
Now for the rear wheel.
At the preliminary center, the rim is offset toward the freewheel side.
Of the two bearings on the freebody,
there's secondary rust directly below the outer bearing.
The cone and ball cup on the rear hub were both black.
The hub shaft directly below the outer bearing of the freebody
has galling marks, so replacement is pretty much certain.
In fact, the inside of the outer bearing was damaged.
I cleaned the freebody and replaced just the outer bearing.
before
after
Once the hub overhaul was complete, the center offset was gone.
However, there's still some slight lateral runout, and
the phase angle I set at the preliminary center and the phase in the image above are definitely not exactly the same,
so I can't definitively say this is all the runout that developed from just disassembling and reassembling the hub.
After finishing the truing work,
a center offset appeared that was nearly the same in direction and magnitude as before the work.
I corrected the center offset.
Starting with the front wheel.
They wanted an overhaul, but both the front and rear hubs had play in them.
The front wheel condition was so bad I couldn't imagine riding it like that,
so maybe they started taking it apart but decided not to touch it themselves after all.
Yep, this is a new shaft waiting to explode.
I tighten the right end first, then use the right 14mm grip width and
loosen the left end with the 5mm Allen key hole on the left side.
The cone pressed onto the hub was the "black" type.
For the steel balls and USB-use black ball races,
they were supposedly switched to silver races back in the day,
but even with the new front hubs that have two fewer bearings than the old ones,
I'm seeing black specs occasionally now.
So apparently they're deliberately manufacturing black specs anew for some reason.
Since the black and silver have the same part numbers, the manufacturer treats them as "the same thing,"
but based on my experience, durability—especially the rust creep resistance for USB use—is noticeably lower with black,
(and I suspect that's why the manufacturer switched to silver back then),
so I can't understand the reason for going back to black ball races.
Since there's no rust creep and the parts are pricey, I'm not replacing them this time.
Also, for some reason the ball cup is silver spec.
I applied DT Spoke Freeze,
and tightened it up securely with the 14mm grip width and the 5mm Allen key on the right end.
Going forward, if I loosen it with the 5mm Allen keys on both ends,
the right end will almost certainly never loosen first.
I didn't check the preliminary center before overhauling the hub,
but after the overhaul there was a slight offset.
I corrected the slight lateral runout and center offset.
Now for the rear wheel.
At the preliminary center, the rim is offset toward the freewheel side.
Of the two bearings on the freebody,
there's secondary rust directly below the outer bearing.
The cone and ball cup on the rear hub were both black.
The hub shaft directly below the outer bearing of the freebody
has galling marks, so replacement is pretty much certain.
In fact, the inside of the outer bearing was damaged.
I cleaned the freebody and replaced just the outer bearing.
before
after
Once the hub overhaul was complete, the center offset was gone.
However, there's still some slight lateral runout, and
the phase angle I set at the preliminary center and the phase in the image above are definitely not exactly the same,
so I can't definitively say this is all the runout that developed from just disassembling and reassembling the hub.
After finishing the truing work,
a center offset appeared that was nearly the same in direction and magnitude as before the work.
I corrected the center offset.