Self locking bearing preload adjuster
A bearing preload adjuster for a bicycle crank set and bottom bracket comprises an adjustment ring for coupling with a bicycle crank arm, a movable plunger comprising an external thread for rotatably coupling with the adjustment ring. The adjustment ring is rotated in order to cause the plunger to extend along an axis of the bottom bracket and apply pressure to a bottom bracket bearing inner race. The adjustment ring is rotated until the clearance in the bearing assemblies and the play in the bottom bracket assembly has been eliminated. This allows the crank assembly to rotate freely, while preventing the crank assembly from sliding side to side inside the bearing bores and along the axis of the crank spindle.
1. A crank set for a bicycle comprising:
a. a drive side crank arm comprising one or more chain rings;
b. a non-drive side crank arm;
c. a spindle;
d. an extendable bearing preload adjuster fit onto the non-drive side crank arm, wherein the bearing preload adjuster is slid over an adjuster boss of the bicycle crank arm to couple the bearing preload adjuster with the bicycle crank set and a bottom bracket assembly, the extendable bearing preload adjuster comprising:
i. an adjustment ring;
ii. a movable plunger comprising an external triple-start thread for rotatably coupling with the adjustment ring; and
iii. a detent spring, wherein the detent spring includes a spring detent feature that engages within one of a plurality of adjustment ring detent features,
iv. wherein each of the movable plunger and the detent spring includes a respective at least one anti-rotation feature that engages in an at least one anti-rotation feature of the adjuster boss,
wherein the adjustment ring is manually rotated to cause the movable plunger to extend along an axis of the bottom bracket assembly inward toward the bottom bracket assembly to apply pressure to a bottom bracket bearing inner race and eliminate a clearance in a bearing assembly of the bottom bracket.
2. The crank set of claim 1 wherein the detent spring prevents the movable plunger from backing out once the movable plunger has been moved in order to apply preload to the bearing assembly of the bottom bracket.
3. The crank set of claim 1 wherein the bearing preload adjuster is rotatable in a counter-clockwise direction.
4. The crank set of claim 1 wherein the bearing preload adjuster further comprises a gasket adapted to prevent water and dirt from contacting the bearing assembly of the bottom bracket.