Spring tune up - Bearing question

[G6612]

I am going to be tearing apart my bike this weekend and regreasing the headset bearings and my crankset. My question is how do I know when to replace my bearings for my crankset (BB30)? I purchased my bike in 2010 and when I upgraded my crankset to the Cannondale Hollowgram SL I used my original bearings. Is there a way to check and see if they need replaced I am thinking if they are still smooth I should be ok. Appreciate some input I would estimate they have about 6000 miles on them.

[rbrtwyn]

If they are smooth they are OK. You can pick the seal off with a thumbtack and apply some marine grease so they keep running smooth.

[lancejohnson]

Any time I'm doing a tune up I like to pull the bearings out and soak them in solvent, give them a good cleaning, and then repack with Phil waterproof grease. I also typically like to use loose balls where I can so that this is a lot easier...

[Phill P]

Don't pull the bearings out, you could damage the races or balls by side loading them.

If the bearings feel smooth with no notches or grity feeling then they are ok. It can be a good idea to lift the seal and clean out the old grease and repack though. A lot of people never bother but it can extend the life of a bearing, and help it feel fresh again.