- The replacer - this person just buys new bearings and cant be bothered.
- The quick and dirty - this person takes the shields off and cleans them and puts the shields back on.
- The mechanic - Takes shields off, takes cages out. cleans cages and races with balls in them.
I have done all three methods personally. I find if you do a cleaning regularly that the quick and dirty should work for you.
You will need a cleaning Unit:
- Bionic Bearing Cleaner - Product
- Paint grade acetone works too but is not a nice chemical.
While you are at it check to see if your nuts need replacing.