Abstract: The invention relates to a braking mechanism and tape cartridge for a tape measure. In accordance with one aspect of the invention, the tape measure includes a housing, a fixed cylindrical surface located in the housing, a reel supported in the housing for rotation, and at least one braking mechanism located on the reel. The braking mechanism includes a flyweight, a spring, and a rail. The spring and rail allow the flyweight to move between a first position, in which the flyweight is not in contact with the fixed cylindrical surface, and a second position, in which the flyweight is in contact with the fixed cylindrical surface. In another aspect, a tape cartridge is provided that includes two sidewalls and a cylindrical wall, which define a container. The tape cartridge is adapted to support a tape assembly therein, and may be mounted in the tape measure housing.