This will vary widely with local climate, miles ridden, and weather conditions during those rides. I'm a "take it all apart, clean it, and grease it" once a year guy, but YMMV. Grease (and "carbon paste which is just grease with grit mixed in) are good for several years but a number of things can shorten that life span significantly.remove it every couple of years to replace the carbon paste. This is an every couple of years thing, not an every month thing. Once every couple of years is not too much to ask, and it should be done with everything on your bike that uses grease. Grease is a consumable.