Step 20: The fork bearings
The fork bearings will fall out of the head tube cups once the forks have been removed. As shown in Figure 20, the bearings have two sides, a ball side and a ring side. Always place the bearing in the cups balls first, or they will not work properly. A stiff fork that does not spin freely is a clear sign of an improperly installed or wrong size bearing in the head tube cups. Yes, there are several sizes of bearing and cups, so keep the same parts together.