Abstract: A bottle holder system mountable to a bicycle (10), wherein said bicycle comprises a down tube (18) and a seat tube (20), wherein said bottle holder system comprises: a first bottle holder (100) comprising (i) a first bottom wall (104) mountable to a rear side of the down tube, (ii) a first left side wall (106), and (iii) a first right side wall (108) all forming a first interior cavity (110) shaped for receiving a first round bottle (112); a second bottle holder (200) comprising (i) a second bottom wall (204) mountable to a front side of the seat tube, (ii) a second left side wall (206), and (iii) a second right side wall (208) all forming a second interior cavity (210) shaped for receiving a second round bottle (212); wherein the down tube, the seat tube and exterior surfaces of said first left side wall, second left side wall, first right side wall and second right side wall cooperate to form an airfoil shape (500).