Bicycle torque detector

A bicycle torque detector, comprising:

• a crank shaft (1) formed with a first ring section (A) and a second ring section (B);
• the first ring section (A) being for receiving a deformation sleeve accommodating ring (3) and a deformable sleeve (2);
• the second ring section serving for receiving a circuit board ring (5);
• a circular casing (8) for enclosing all the crank shaft (1), the deformation sleeve accommodating ring (3), the sleeve (2), and the circuit board ring (5);
• wherein the first ring section (A) of the crank shaft (1) is formed with at least one resisting portion (1A);
• the deformable sleeve (2) has at least one resisting portion (2A);
• the resisting portion (1A) of the crank shaft (1) resists against one end of the deformation sleeve accommodating ring (3);
• another end of the deformation sleeve accommodating ring (3) resists against the resisting portions (2A) of the deformable sleeve (2);
• wherein the deformation sleeve accommodating ring (3) is adhesive by a sensing sheet (3A) which is signally connected to the circuit board ring (5);
• and
• wherein by the one end of the deformation sleeve accommodating ring (3) resisting against the crank shaft (1) and the another end of the deformation sleeve accommodating ring (3) resisting against the deformable sleeve (2), a rear end of the deformable sleeve (2) is engaged to a chain sleeve (4);
• when the crank shaft (4) drives the chain sleeve (4) to rotate, the torque of the crank shaft (4) deforms the resisting portions (1A) of the crank shaft (1) and the resisting portions (2A);
• the deformation is detected by the sensing sheet (3A) of the deformation sleeve accommodating ring (3) and values of the deformation are transferred to the circuit board ring (5) for determining variations of the torque.