A locking mechanism adapted for locking a bicycle fork has a locking sheath and an adjusting rod. The locking sheath is adapted to be positioned within the bicycle fork. The adjusting rod is adapted to slidably engage the locking sheath. The adjusting rod is adapted to rotate with respect to the locking sheath between a locked configuration and an unlocked configuration. A first interlocking element of the adjusting rod lockingly engages with a second interlocking element of the locking sheath in the locked configuration, and the first and second interlocking elements are disengaged from each other when the adjusting rod is rotated to the unlocked configuration.