The present invention is directed to a child carrier assembly 10 adapted to be removably mounted to a bicycle 12, said carrier assembly 10 comprising a seat 15, a backrest portion, a footrest portion, two side portions, means for seating a child and means for supporting a child while seated, a docking assembly 11A, 11B for connecting said child carrier assembly 10 to said bicycle 12, where said child carrier assembly 10 is adapted to function as a convertible stroller by means of comprising a wheel assembly 13 and a handle bar 16, where said docking assembly 11A, 11B comprises one partbeing fixed to said bicycle 12 and one part being fixed to said child carrier assembly 10, where said connection parts being releaseably mountable to one another, wherein said docking assembly 11A, 11B comprises a spring loaded mechanism and wherein said spring loaded mechanism controls said releasable docking assembly 11A, 11B by means of comprising one movable part 51 and one fixed part, where the docking assembly 11A, 11B has a locking function so that an upper docking assembly unit 11A fixed to said carrier assembly (10) is dockable and undockable to a lower docking assembly unit 11B fixed to said bicycle, and wherein the upper docking assembly unit 11A comprises two separate unlocking handles 41a, 41b.