A light bag rack (10) for a bicycle includes a U-shaped frame (42) having first and second rods (48, 50) extending between a closed securing end (44) and an open mounting end (46) of the rack (10) and defining a pinch point (52) between the ends (44, 46). The rods (48, 50) are sufficiently flexible to permit the open mounting end (46) to expand around first and second bicycle seat frame rails (16, 18) forward of a seat post (14) and to pass between the seat frame rails (16, 18) rearward of the seat post (14) so that the closed securing end (44) contacts the seat frame rails (16, 18) forward of the seat post (14) to secure the rack (10) to the seat frame rails (16, 18). A load portion (70) of the rack (10) supports a utility bag (84).