text: how many ball bearings are in the freewheel part of the hub on a 26" shimano mountain bike? there are loose ball bearings in the freewheel part of a mountain bike. does anyone know how many go in there? i disassembled 2 mountain bikes to make an electric bike. now i am putting one back together and i have 2 sets but i lost some from each set and it leaves me with no clue. these are the bearing underneath the shimano freewheel locking nut... the bearing are loose under there. thank you! ok this is simple. ive taken apart a few shimano hubs and they have had either 9 or 11 ball bearings on each side.  easy way to figure out how many:  -have a tray of grease on hand -lay on some grease in the area were the bearings go -dip each ball into the grease and use tweezers to put them in place -only a certain amount will fit into the bearing race -put the axle back through when ur done and see if it rotates smoothly  good luck