Continuously variable transmission unit, such as for a bicycle

A continuously variable transmission unit, comprising:

• a first drive element that is rotatable about a first axis;
• a second drive element that is rotatable about a second axis parallel to the first axis, wherein the first drive element and the second drive element are movable relative to each other in a direction transverse to the first and second axis;
• and
• first coupling elements provided at a constant first radius from the first axis and at a variable second radius from the second axis,
• for transferring torque between the first drive element and the second drive element;
• wherein at least one, or each, of the first coupling elements comprises a first and a second coupling body, and the first drive element comprises a first concentric guide extending concentrically around the first axis having a first guide part to a first side of the second drive element and a second guide part to an opposite second side of the second drive element;
• wherein the first coupling body comprises a first wedging body, and the second coupling body comprises a second wedging body:
• wherein the first wedging body is arranged to engage a radially inner circumferential surface and a radially outer circumferential surface of the first guide part when driven in the second tangential direction, and the second wedging body is arranged to engage a radially inner circumferential surface and a radially outer circumferential surface of the second guide part when driven in the second tangential direction.