From what the LBS told me it's the hub worn out.He showed me the play in it after he
pulled the cassette off.
The hub btw is a Shimano M475.
Unfortunately I have to wait until Monday to drop off the bike because of Chinese New Year here.
Everything closes for a week!
Even the postal system.
At least I have a spare to ride round on.
What kind of regular maintenance can I do besides repacking the hubs every couple thousand miles?
Thanks