Keep the bearings greased and the tires inflated to the proper pressure and it should last a long time. Keep an eye on little things that may pop up and get them taken care of before they turn into major issues like rust spots, wire chafing and lighting issues. As for the bearings, you have to keep the seals in good shape. One of the worst things that can happen is to have water get into the hub. If you grease it and it pushes out any water you may want to pull the hub to find out why.