Derailleur

Derailleur
Derailleur: apparatus used to transfer the chain from one toothed wheel to another.
Shifter: solid, movable arm, attached to a fixed point, that increases applied force.
Locking bolt: piece of metal, placed at the centre, with a head at one end and a thread at the other. Used with a nut.
Control cable: set of braided steel wires, used to control the brakes.
Sheath bushing: piece that holds the brake cable in place.
Control cable: set of braided steel wires, used to control the brakes.
Tension spring: part that returns a second part to its initial position.
Adjustable stop screw: small piece of metal that regulates the tension of the gear cable.
Roller: metal protuberance used to transfer the chain from gear to gear.
Frame or roller: mechanism that permits the operation of the moving part of the bicycle.
Clutch: cylindrical part.
Jockey roller: metal protuberance used to transfer the chain from gear to gear.
Cable: set of braided steel wires used to control the brakes.
Chain guide: part of the mechanism guiding movable parts.
Nut or hub: piece of metal with a threaded hole at its centre. Used with a bolt.
Gear: wheel of the gear system.
Frame: chassis of a bicycle.

Photo :

EN : Bridge structure
FR : Structure de pont
ES : Estructura del puente

Bridge 
          structure

A bridge is a structure built to span a gorge, valley, road, railroad track, river, body of water, or any other physical obstacle. Designs of bridges vary depending on the function of the bridge and the nature of the terrain where the bridge is to be constructed.