Fixing that bicycle!

My friend keep telling that his bicycle keeps on making so much noise coming from its wheels. I told him that maybe the bearing inside on it is already worn out so i told him that i can help him out to change those bearing that making the wheels to makes so much noise. I told him that he can buy new bearings to install on it so that way he can save money rather than buying a new set of wheels. Im glad he listened to me and I’m happy that I help him out.