its upper and lower ends each counter bore 52 holding a bearing assembly 54 a fork ring 11 is fitted over a bottom end 58 of the fork yoke 12 and rests on a fork bridge 15 the fork 14 slides into the lower end 70 of the head tube 6 so that the fork bridge 15 bears on the fork ring 11 which in turn bears on the lower bearing assembly 54 the fork bridge 15 is attached to the outside of the fork yoke 12 so as to not close an opening in the bottom end 58 of the fork yoke 12 to an internal passageway 56 through the fork yoke 12 the top end 60 of the fork yoke 12 protrudes above the upper end 70 of the head tube 6 and is externally threaded and split with two longitudinal slits not labeled the top end 60 of the fork yoke 12 is open and receives the first end 16 of the handlebar stem 2 a head locking collar 30 is internally threaded and screwed onto the upper end 70 of the fork yoke 12 an abutment 74 on the bottom of the head locking collar 30 bears on the bearing assembly 54 in the upper end 70 of the head tube 6 to compress the bearing assemblies 54 and hold the fork 14 in the head tube 6 head locking collar 30 is.