A customer brought in a rear wheel built with the FH-9000, the last generation Dura-Ace hub.
When I shook the freewheel body by hand with the sprockets attached,
it rattled badly—the internal parts of the freewheel body are quite worn.
There's no way to keep using it as-is,
so the freewheel body needs to be replaced.
I removed the freewheel body.
Those dreaded splines (→here).
Where the area around the splines drops down a level,
a washer is installed, but
it came off stuck to the removed freewheel body due to the grime.
The hollow bolt that secures the freewheel body—on most Shimano hubs it's removed with a 10mm Allen key,
but on this aluminum hollow bolt you use a 14mm Allen key.
Also, this hollow bolt is only good for "one use."
Once it's been installed and removed,
the instructions say you must always replace it with a new one.
There is individual sale of the hollow bolt,
but when you buy the freewheel body itself,
it comes with the washer and hollow bolt as a set
under the unit called "freewheel assembly,"
so even if you don't know about it, you won't forget to buy them.
Anyway, this FH-9000 freewheel assembly unit
currently has a list price of 33,495 yen including tax.
That's a bit too expensive, so
I decided to repair it with a freewheel body from the same-generation Altegra hub FH-6800,
which also uses a 14mm Allen key hollow bolt,
but Shimano no longer has it in stock.
Come on, seriously?
Well, we found one at a shop with good inventory, so
this time we managed to make it work.
↑The 14mm hex socket of the FH-9000 hollow bolt
↑FH-6800 freewheel body
↑FH-6800 14mm Allen key hollow bolt
It fit.
Also, there was pitting on the right cone,
but the minimum unit to replace that is
the "hub axle with right cone and right end,"
otherwise it becomes "everything inside the hub except the seals,"
which includes the above plus bearing balls for both sides,
the left cone, the seal cover with bearing play adjustment mechanism,
the left end bolt, and the washer set for it.
But the manufacturer inventory for both options has ended.
In other words, if the FH-9000 cone gets pitting,
it can't be repaired anymore.
Top-model hubs from Campagnolo and Fulcrum that also use cup-and-cone bearings
can have the ball races replaced, but...
Also, if the cup on the hub body develops pitting,
there's no spare parts option at all, so it can't be repaired.
The cup is less prone to pitting than the cone,
so if you replace the cone when only it has pitting,
there's almost no problem going forward.
When I shook the freewheel body by hand with the sprockets attached,
it rattled badly—the internal parts of the freewheel body are quite worn.
There's no way to keep using it as-is,
so the freewheel body needs to be replaced.
I removed the freewheel body.
Those dreaded splines (→here).
Where the area around the splines drops down a level,
a washer is installed, but
it came off stuck to the removed freewheel body due to the grime.
The hollow bolt that secures the freewheel body—on most Shimano hubs it's removed with a 10mm Allen key,
but on this aluminum hollow bolt you use a 14mm Allen key.
Also, this hollow bolt is only good for "one use."
Once it's been installed and removed,
the instructions say you must always replace it with a new one.
There is individual sale of the hollow bolt,
but when you buy the freewheel body itself,
it comes with the washer and hollow bolt as a set
under the unit called "freewheel assembly,"
so even if you don't know about it, you won't forget to buy them.
Anyway, this FH-9000 freewheel assembly unit
currently has a list price of 33,495 yen including tax.
That's a bit too expensive, so
I decided to repair it with a freewheel body from the same-generation Altegra hub FH-6800,
which also uses a 14mm Allen key hollow bolt,
but Shimano no longer has it in stock.
Come on, seriously?
Well, we found one at a shop with good inventory, so
this time we managed to make it work.
↑The 14mm hex socket of the FH-9000 hollow bolt
↑FH-6800 freewheel body
↑FH-6800 14mm Allen key hollow bolt
It fit.
Also, there was pitting on the right cone,
but the minimum unit to replace that is
the "hub axle with right cone and right end,"
otherwise it becomes "everything inside the hub except the seals,"
which includes the above plus bearing balls for both sides,
the left cone, the seal cover with bearing play adjustment mechanism,
the left end bolt, and the washer set for it.
But the manufacturer inventory for both options has ended.
In other words, if the FH-9000 cone gets pitting,
it can't be repaired anymore.
Top-model hubs from Campagnolo and Fulcrum that also use cup-and-cone bearings
can have the ball races replaced, but...
Also, if the cup on the hub body develops pitting,
there's no spare parts option at all, so it can't be repaired.
The cup is less prone to pitting than the cone,
so if you replace the cone when only it has pitting,
there's almost no problem going forward.