Bicycle Mechanics - hub bearing question

how do i know if my front hub needs to be greased, im buying a road bike, and from who im buying it greased it 2 months ago. He's a bike mechanic and all but i just want to know what are the signs of the bearings needing grease

Remove the wheel from the bike, and rotate the front axle by hand. It should turn smoothly, with no feeling of grit or roughness, and no play. If it feels rough, is hard to turn, or has a lot of slop, it'll need to be rebuilt.

Well, if a mechanic overhauled the hub two months ago, you're probably okay. And since the seller is a mechanic and he's your friend, you could ask him about what to look for in order to tell if a hub needs to be overhauled again. (Not intending to be curt; I just don't have time to reply right now.)

if the bearings are bad, is it possible that it will lock up while riding?

if the bearings are bad, is it possible that it will lock up while riding?
(a little more time now) No, virtually zero chance that the bearings will lock up. They will just turn with more friction. A wheel has such a large diameter, the bearings would have to be nearly welded shut for the wheel to stop turning while you're riding.

(a little more time now) No, virtually zero chance that the bearings will lock up. They will just turn with more friction. A wheel has such a large diameter, the bearings would have to be nearly welded shut for the wheel to stop turning while you're riding.well thats a sign of relief, because i broke my arm pretty badly going over the bars. had surgey, so im scared of flipping again. Thanks for taking your time to help me out, i appreciate it

Did you go over the bars because your hub bearings locked up? I find that hard to believe. Not impossible, but highly unlikely. But I can understand why you're cautious here.

Did you go over the bars because your hub bearings locked up? I find that hard to believe. Not impossible, but highly unlikely. But I can understand why you're cautious here.no i went over because i was going off a ramp, and my friend got right in front of me, i didnt pull up so i flipped.

Back wheel failure (rim, spokes or hub) is much more likely because it carries much more weight than the front and also has to carry the driving load from the chain.

Back wheel failure (rim, spokes or hub) is much more likely because it carries much more weight than the front and also has to carry the driving load from the chain.
Yeah, but even the rear wheel doesn't fail by locking up all of a sudden. The bearings just get rougher and have more friction when they turn. Unless you break an axle, which happened more with freewheel hubs, but virtually never with modern cassette hubs.