Hi, I have a son who has managed to break up / collapse the inner bearing race within the rear cassette on 2 bikes, his and mine. I have managed to get the cassette off with no bother but cannot see how to get to the bearings inside the hub, is the cassette hub removable, if so how? they are both shimano assemblies on mountain bikes.
Many thanks in advance!
The 'cassette hub' (called a freehub) can be removed by putting a 10mm allen wrench into the end after the axle has been taken out. This unscrews a sleeve bolt that holds on the freehub.
I'm slightly confused what you mean though. On a cassette hub, the axle bearings on the cassette side are out at the end of the freehub. Maybe you have a "freewheel" and managed to remove the cogs from the freewheel without taking it off the hub? So maybe I'm misunderstanding what difficulty you're having. Sometimes hubs have press in dust shields that cover the ends of the hub and just leave room for the axle to go through. You can usually get bearings out around these, but sometimes it's easier to pop them out.
This Sheldon article explains freewheel or freehub.
Either way you have to remove the axle to replace bearings.
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