how often should you change bearings?

[speed demon]

I've been running my brushless motor for awhile now and figure it might be a good idea. Would you guys suggest the oem bearings or should I go with ceramic bearings? Thanks.

[neweuser]

Ceremics are nice....I never had the need for them however.

[aqwut]

I've done the ceramic upgrade.. and it is nice.. but all of the stock bearings on the other motors are fine.. I just keep lubing them once a month... I would stick to stock and upgrade when/if they go...