Bicycle

A bicycle comprising a front wheel, a rear wheel, a pedal gear device, a direction control device, and a main frame, which connects the aforementioned components, the direction control device being used for controlling the direction of the front wheel, characterized in that the direction control device comprises:

• a handlebar;
• a steering stem connected to the main frame, wherein the steering stem comprises a longitudinal rod and a horizontal rod, the longitudinal rod being joined to the horizontal rod, the horizontal rod being substantially parallel to the handlebar;
• and
• two adjusting stems, each of the adjusting stems comprising an adjusting main body, a first clamping portion, and a second clamping portion, wherein the first clamping portion and the second clamping portion are located at both ends of the adjusting main body, and
• both ends of the horizontal rod are clamped by each first clamping portion with two clamping states:
• a fastening state and a non-fastening state;
• the handlebar is clamped by each second clamping portion with two clamping states:
• a fastening state and a non-fastening state;
• and
• a quick switch device coupled to each adjusting stem, the quick switch device being used for controlling the clamping state of each first clamping portion and each second clamping portion.