A customer left a Racing Zero Carbon (high-end racing wheelset) with me for service.
I have both the front and rear wheels, and they were inspected at our shop a few years ago.
The mileage is around 3,000 km, so
these aren't wheels that get regular use.
There's basically no runout, and the hub bearings show no problems,
so I wasn't planning to post about this, but...
The hub axle won't turn forward by hand.
It will turn backward only in sync with the freewheel body.
This happens because the freewheel body has seized onto the hub axle.
The reason it won't turn forward is that the pawls catch on the ratchet teeth.
In most cases, this symptom occurs because
the bearing on the outside of the freewheel body has rusted.
The image above shows the state after removing the end nut and washer.
I couldn't turn the hub axle forward by hand,
but when I inserted an Allen key into the hex hole at the end of the axle,
the seizing released and it rotated with a grinding sound.
Still, I couldn't pull the freewheel body out by hand,
so I had to remove the "hub axle with freewheel body" from the hub shell
and tap out the freewheel body from behind.
I removed the freewheel body and lightly wiped the hub axle.
There's rust transfer right below the outer bearing of the freewheel body.
I removed as much of the rust band as possible.
↑The inner race of the outer bearing,
the part that contacts the hub axle, is rusted.
The inner bearing wasn't damaged enough to warrant replacement.
Except in cases where only the outer bearing was replaced in the past,
it's common to replace both the outer and inner bearings,
or only the outer one,
but replacing just the inner bearing is almost unheard of.
I replaced the outer bearing.
The pawls and pawl springs showed no issues, so I didn't replace them.
I just cleaned them.
This is a separate case, but coincidentally on the same day I replaced
the freewheel body of a Nomu Lab Wheel No. 6 (custom Japanese wheelset),
and at the time of drop-off the hub axle was seized.
This is also a rear wheel that "wasn't being used regularly."
Rust progression inside accelerates especially when water gets in and the wheel sits unused.
I have both the front and rear wheels, and they were inspected at our shop a few years ago.
The mileage is around 3,000 km, so
these aren't wheels that get regular use.
There's basically no runout, and the hub bearings show no problems,
so I wasn't planning to post about this, but...
The hub axle won't turn forward by hand.
It will turn backward only in sync with the freewheel body.
This happens because the freewheel body has seized onto the hub axle.
The reason it won't turn forward is that the pawls catch on the ratchet teeth.
In most cases, this symptom occurs because
the bearing on the outside of the freewheel body has rusted.
The image above shows the state after removing the end nut and washer.
I couldn't turn the hub axle forward by hand,
but when I inserted an Allen key into the hex hole at the end of the axle,
the seizing released and it rotated with a grinding sound.
Still, I couldn't pull the freewheel body out by hand,
so I had to remove the "hub axle with freewheel body" from the hub shell
and tap out the freewheel body from behind.
I removed the freewheel body and lightly wiped the hub axle.
There's rust transfer right below the outer bearing of the freewheel body.
I removed as much of the rust band as possible.
↑The inner race of the outer bearing,
the part that contacts the hub axle, is rusted.
The inner bearing wasn't damaged enough to warrant replacement.
Except in cases where only the outer bearing was replaced in the past,
it's common to replace both the outer and inner bearings,
or only the outer one,
but replacing just the inner bearing is almost unheard of.
I replaced the outer bearing.
The pawls and pawl springs showed no issues, so I didn't replace them.
I just cleaned them.
This is a separate case, but coincidentally on the same day I replaced
the freewheel body of a Nomu Lab Wheel No. 6 (custom Japanese wheelset),
and at the time of drop-off the hub axle was seized.
This is also a rear wheel that "wasn't being used regularly."
Rust progression inside accelerates especially when water gets in and the wheel sits unused.