Foldable bicycle

A foldable bicycle comprising:

• a head tube;
• a seat tube having a top end and bottom end;
• a down tube having a first front end and a first rear end, the first front end being joined to the head tube;
• two seat stays, each having a respective second front end and a respective second rear end;
• a forward shaft joined to both of the second front ends and being removably joinable to the seat tube, to selectively join the seat stays to and remove the seat stays from the seat tube;
• two chain stays, each having a respective third front end and a respective third rear end, each of the third rear ends being joined to the second rear end of a respective one of the seat stays;
• a pedal axle extending along a pedal axis;
• a bottom bracket tube traversed by the pedal axle, the bottom bracket tube being joined to at least one of the first rear end of the down tube and the bottom end of the seat tube;
• at least one non-rotating washer centered about a rotation axis, the at least one non-rotating washer being joined to the bottom bracket tube and disposed at an angle with the pedal axle and the pedal axis, such that the rotation axis is at a non-zero angle with respect to the pedal axis;
• at least one rotating washer joined to and rotatable with respect to the at least one non-rotating washer around the rotation axis, the at least one rotating washer being joined to third front ends of the chain stays, such that chains stays are configured to be rotated about the rotation axis for folding and unfolding the bicycle.