A customer brought in a Shamal Carbon DB...
Well, that's not exactly how it happened.\br/>
This rear wheel was attached to a bike that came in for a shift cable replacement.
When I saw the sticker from the shop where it was purchased on the frame,
I said, "Why don't you just have them replace it?"
But apparently they didn't trust that shop, so through a personal referral
they brought it to us instead.
So when I tried to replace the shift cable,
with the rear derailleur still having no cable threaded through it,
when I spun the crank, the chain didn't sit on the top gear
but rather two gears up from that.
And on top of that, the freewheel coasting sound was off.\br/>
When I removed the rear wheel, the right locknut was abnormally loose.\br/>
The freewheel body with the sprocket was clearly
protruding from the hub shell.
I thought this would cause the disc rotor to be constantly rubbing,
but even if the right end stretches, the distance from the left end
to the rotor mounting surface doesn't change,
so it seems difficult to notice something wrong on that account.
However, I would think you'd notice something amiss because you can't shift to the top two gears
or because the wheel rotation just feels weird,
but I shouldn't assume that noticing subtle warning signs before they become obvious problems—
something I do because I'm a professional—is normal.\br/>
↑pushing upward
↑pushing downward
The freewheel body with sprocket is eccentric
relative to the stationary hub axle.\br/>
I removed the locknut and the spacer that was next to it.
The bearing inner race on the hub axle had rusted and seized,
so it wouldn't come out with hand force alone.
The hub axle with freewheel body had to be removed from the hub shell first,
then driven out by tapping from inside the freewheel body, but\br/>
the freewheel body still wouldn't come off.\br/>
The contents of the outer bearing had completely deteriorated,
so the inner race separated by coming out of the bearing.\br/>
The outer race is still press-fit and remains on the freewheel body side.
This usually happens with just the outer bearing,
but if it happens with the inner bearing, you're in hell.
There's a workaround for that, but it's job security.
In this case, the inner bearing
was intact enough to be driven out.
What was dangerous in the image above was the thick layer of clay-like mud debris
that had formed on the inner wall of the freewheel body.\br/>
I removed the outer race of the outer bearing and cleaned the debris from the inner wall.
The inner bearing was also turbid enough in its rotation to warrant replacement, so\br/>
I replaced it. The size is 6902, and we had it in stock.
It was lucky they brought it to us.
If they'd taken it to the shop where they bought the bike,
this kind of repair would be absolutely impossible. At least not same-day.
How can I say that with such certainty? Because I know those guys well.
Incompetent, incompetent, incompetent!
Well, regarding this Shamal Ultra Carbon DB,
since it was purchased through overseas online shopping,
they'd probably use that as a reason to say "we can't fix it."\br/>
The hub axle after cleaning is like this.
I then lightly removed the rust from here.\br/>
There was play and the eccentric condition had persisted for a good while,
so the area around the pawls of the freewheel body
not only showed marks from contact with the ratchet peaks
but also wear on the inner edge.\br/>
I assembled the parts.
This assembly was just for taking the photo;
afterwards I removed the freewheel body again and greased around the ratchet,
and although it's not in the photos, I also installed the seal parts
that go between the spacer and bearing after the locknut.\br/>
↑replaced parts
↑inner bearing
↑outer bearing
The two seals of the outer bearing look
like they're different sizes, but\br/>
when you overlay them, you can see that one of them has its inner edge
worn away by the eccentricity, which is why they appear different.
The wear pattern isn't even a clean circle either.\br/>
By the way, because of this work, the oil residue that couldn't be removed
with hand cleaner and required a bath to get off
got under my fingernails and deep in my fingerprints,
which meant I couldn't eat naan with my hands that evening.\br/>
※refers to eating naan bread by hand, just to clarify
Well, that's not exactly how it happened.\br/>
This rear wheel was attached to a bike that came in for a shift cable replacement.
When I saw the sticker from the shop where it was purchased on the frame,
I said, "Why don't you just have them replace it?"
But apparently they didn't trust that shop, so through a personal referral
they brought it to us instead.
So when I tried to replace the shift cable,
with the rear derailleur still having no cable threaded through it,
when I spun the crank, the chain didn't sit on the top gear
but rather two gears up from that.
And on top of that, the freewheel coasting sound was off.\br/>
When I removed the rear wheel, the right locknut was abnormally loose.\br/>
The freewheel body with the sprocket was clearly
protruding from the hub shell.
I thought this would cause the disc rotor to be constantly rubbing,
but even if the right end stretches, the distance from the left end
to the rotor mounting surface doesn't change,
so it seems difficult to notice something wrong on that account.
However, I would think you'd notice something amiss because you can't shift to the top two gears
or because the wheel rotation just feels weird,
but I shouldn't assume that noticing subtle warning signs before they become obvious problems—
something I do because I'm a professional—is normal.\br/>
↑pushing upward
↑pushing downward
The freewheel body with sprocket is eccentric
relative to the stationary hub axle.\br/>
I removed the locknut and the spacer that was next to it.
The bearing inner race on the hub axle had rusted and seized,
so it wouldn't come out with hand force alone.
The hub axle with freewheel body had to be removed from the hub shell first,
then driven out by tapping from inside the freewheel body, but\br/>
the freewheel body still wouldn't come off.\br/>
The contents of the outer bearing had completely deteriorated,
so the inner race separated by coming out of the bearing.\br/>
The outer race is still press-fit and remains on the freewheel body side.
This usually happens with just the outer bearing,
but if it happens with the inner bearing, you're in hell.
There's a workaround for that, but it's job security.
In this case, the inner bearing
was intact enough to be driven out.
What was dangerous in the image above was the thick layer of clay-like mud debris
that had formed on the inner wall of the freewheel body.\br/>
I removed the outer race of the outer bearing and cleaned the debris from the inner wall.
The inner bearing was also turbid enough in its rotation to warrant replacement, so\br/>
I replaced it. The size is 6902, and we had it in stock.
It was lucky they brought it to us.
If they'd taken it to the shop where they bought the bike,
this kind of repair would be absolutely impossible. At least not same-day.
How can I say that with such certainty? Because I know those guys well.
Incompetent, incompetent, incompetent!
Well, regarding this Shamal Ultra Carbon DB,
since it was purchased through overseas online shopping,
they'd probably use that as a reason to say "we can't fix it."\br/>
The hub axle after cleaning is like this.
I then lightly removed the rust from here.\br/>
There was play and the eccentric condition had persisted for a good while,
so the area around the pawls of the freewheel body
not only showed marks from contact with the ratchet peaks
but also wear on the inner edge.\br/>
I assembled the parts.
This assembly was just for taking the photo;
afterwards I removed the freewheel body again and greased around the ratchet,
and although it's not in the photos, I also installed the seal parts
that go between the spacer and bearing after the locknut.\br/>
↑replaced parts
↑inner bearing
↑outer bearing
The two seals of the outer bearing look
like they're different sizes, but\br/>
when you overlay them, you can see that one of them has its inner edge
worn away by the eccentricity, which is why they appear different.
The wear pattern isn't even a clean circle either.\br/>
By the way, because of this work, the oil residue that couldn't be removed
with hand cleaner and required a bath to get off
got under my fingernails and deep in my fingerprints,
which meant I couldn't eat naan with my hands that evening.\br/>
※refers to eating naan bread by hand, just to clarify