A bicycle suspension adjustor is provided with a rotational input member, an axial output member and a rotation-to-axial movement converting structure. The rotation-to-axial movement converting structure includes a first converting member operatively coupled to a rotational input member and a second converting member facing the first converting member. At least one rolling member is operatively disposed between the first and second converting members. One of the converting members is operatively coupled to an axial output member. The rolling member is in rolling contact with the first and second converting members so that the rolling member induces relative displacement with respect to both of the first and second converting members as the rotational input member rotates the first converting member in response to a rotational movement of the rotational input member.