Needing to replace the Bearings as bike's handle bars stick after a while of in-activity. Looking on-line, under OEM Steering it only shows 1 set of bearings needed but it's my understanding that if this is to be done right, 2 sets are needed (Top & Bottom). Would I be correct i my understanding that the diagram under the "Steering" section is for the Top Bearing and if so, where can I find the Bottom Bearing ? In anticipation ... Thanks for your help.