The energy that comes from the sun in the form of radiation is absorbed by the plants on the earth and converted into chemical energy through the process of Photosynthesis.
Plants are ingested by animals and humans.
The food we eat is converted into energy for the body through chemical reactions. This energy is used to maintain the body alive and is also used to power the muscles.
The muscles exert forces on objects including the pedals of the bicycle. The force on the pedals creates torque and therefore an angular acceleration which means that the energy of the muscles is converted into rotational kinetic energy. This rotational kinetic energy is transmitted to the wheel through the chain of the bicycle.
The circular movement of the wheels causes a linear movement of the bicycle, this means that the rotational kinetic energy is been converted into linear kinetic energy.