I'm not sure what the recommended service times are for pivot bearings or wheel bearing or head bearings for that matter but my suggestion would be if you think they need to be greased you're right, they do. And if you just the bike brand new last year, you're right again, grease them. I can tell you i've seen what the factory calls "grease" in these areas on a brand new out of the box motorcycle. It's a wonder something isn't squeaking on the way out the door. For the amount of money people pay for these things and as fast as they fly down the road there is barely enough grease in the bike to see on your finger. If you don't believe me take a wheel off or your rear suspension linkage apart and see for yourself. So the moral of the story to all who read this, yes your bearings need to be greased.