Apparatus and method for sensing power in a bicycle

A driven wheel comprising:

• an outer circumferential member contactable with a stationary member, the driven wheel receiving a rotational driving force from a driving member, said rotational driving force driving the driven wheel into rotation to propel the driven wheel into a translational motion relative to the stationary member while the outer circumferential member contacts the stationary member;
• a torque coupling member mounted within the driven wheel and interconnected with the driving member, wherein the torque coupling member transfers the rotational driving force to the driven wheel to drive the driven wheel into rotation;
• and
• sensing means mounted directly to the torque coupling member for generating a signal indicative of strain in the torque coupling member;
• wherein the signal indicative of strain in the torque coupling member provides a direct indication of torque in the torque coupling member without intermediate mechanical parts between the sensing means and the torque coupling member.

A method of measuring strain in a driven wheel comprising:

• providing the driven wheel with an outer circumferential member adapted to contact a stationary member;
• coupling a rotational driving force from a driving member to the driven wheel by mounting a torque coupling member within the driven wheel and drivingly interconnecting the torque coupling member with the driving member, wherein said rotational driving force drives the driven wheel through the torque coupling member into rotation to propel the driven wheel into a translational motion relative to the stationary member using the contact between the outer circumferential member and the stationary member;
• and
• connecting a sensor directly to the torque coupling member without any intermediate mechanical parts therebetween, wherein the sensor is operable to provide a signal directly indicative of strain in the torque coupling member which corresponds to a direct indication of torque in the torque coupling member.

A torque coupling arrangement for interconnection between a driving member and a wheel for rotating the wheel about an axis of rotation, comprising:

• a first force transferring member drivingly interconnected with the driving member in a first location so as to be rotatable in response to rotation of the driving member, wherein the first force transferring member includes at least one laterally extending wall extending in a direction substantially parallel to the axis of rotation of the wheel;
• a second force transferring member drivingly interconnected with the wheel and drivingly interconnected with the first force transferring member at a second location laterally spaced from the first location, wherein the laterally extending wall extends between the first and second locations, wherein the second force transferring member is rotatable in response to rotation of the first force transferring member for imparting rotation to the wheel;
• and
• a strain sensor connected to the laterally extending wall of the first force transferring member for generating a single indicative of strain in the wall to provide an indication of torque in the torque coupling arrangement.