Cable routing system of bicycle and stem thereof

A cable routing system of a bicycle, comprising:

• a stem including a body and a top cap, wherein the body has a bottom portion, an engaging hole, and a communicating hole formed on the bottom portion, and wherein the communicating hole has a curved shape;
• the engaging hole and the communicating hole are disposed on the bottom portion of the body of the stem and are arranged apart from each other, and the communicating hole is disposed in front of the engaging hole in a riding direction;
• a shape of the top cap matches with a shape of the body;
• the top cap fixedly covers the body;
• the top cap and the body are enclosed to form a receiving space communicating with the engaging hole;
• a frame including a head tube, wherein the head tube has a top portion and a bottom portion;
• the top portion has an upper mounting hole, and the bottom portion has a lower mounting hole;
• a fork including a steering tube, wherein the steering tube sequentially passes through the lower mounting hole, the upper mounting hole, and the engaging hole to be connected to the stem, so that the stem is engaged with the steering tube and is located on the top portion of the head tube;
• the bottom portion of the body of the stem faces the top portion of the head tube;
• an expander which is disposed in the steering tube of the fork by being screwed with a fixing bolt, wherein the expander has at least one cable passage, which communicates with the receiving space and the engaging hole;
• and
• at least one cable, wherein the at least one cable extends into the steering tube from outside by passing through the receiving space of the stem and the at least one cable passage;
• an end of the at least one cable is connected to a bicycle controller, and another end thereof is connected to a bicycle component.

A stem of a bicycle, wherein the bicycle includes a handlebar, a frame including a head tube, and a fork;

• the stem has a receiving space therein;
• an end of the stem is connected to the handlebar;
• another end of the stem has an engaging hole communicating with the receiving space;
• the stem has a bottom portion;
• the engaging hole is formed on the bottom portion of the stem;
• the head tube has a top portion and a bottom portion, wherein the top portion has an upper mounting hole, and the bottom portion has a lower mounting hole;
• the fork includes a steering tube, which sequentially passes through the lower mounting hole, the upper mounting hole, and the engaging hole to be connected to the stem, so that the stem is engaged with the steering tube and is located on the top portion of the head tube;
• the stem is characterized in that:
• when the stem is engaged with the steering tube and is located on the top portion of the head tube, the bottom portion of the stem faces the top portion of the head tube;
• the bottom portion of the stem further comprises a communicating hole formed thereon with a curved shape, wherein the communicating hole and the engaging hole are disposed apart from each other, and the communicating hole is closer to the handlebar than the engaging hole, and the communicating hole communicates with the receiving space of the stem;
• wherein the stem further comprises an expander disposed in the steering tube of the fork and is located in the engaging hole;
• a fixing bolt is screwed with the expander, so that an outer diameter of the expander expands to be tightly fixed in the steering tube, wherein the expander has at least one cable passage;
• the at least one cable passage communicates with the receiving space via the engaging hole, and is capable of being passed through by a cable which enters an inside of the steering tube via the receiving space.