Subject: A Bicycle: Technical Description and Labeling
Bicycles are 19th century inventions that brought significant impact on the transport industry. Their construction is of simple materials comprising of metal and rubber primarily. Locomotive power is achieved through muscle power and while the designs for the machine are simple, early versions consisted of two or one-wheeled devices that carried the rider on a seat perched laterally over the machine. While versions of the machine today differ in terms of functionality, cosmetic appliances and structure, the above labeled picture sums up the invention. Today, as from their onset, bicycles are used for a variety of purposes including competitive sports, leisure activities, exercise regimes, as transportation facilitators, entertainment etc.
The machine principally comprises of a frame suspended over two wheels. The frame, consisting of a seat-tube and/or a saddle-bar, handle-bar stem and a head tube, is linear in design thus necessitates caution when in use by the rider. Appendages include the handle-bars, crank-wheel, crank-arm and peddles. Wheels are attached to the frame via the hub that attaches to the tire wheels via a spoke system that supports the rim. Motion occurs via peddling where the rider applies muscle force on peddles which rotate about their axis and propel the machine via a chain system connected to the rear wheel. The chain system itself is a simple set of metal links attached to each other in a closed loop. Cogs attached to an axle suspended perpendicularly from the crank arm on the peddle grip into the slots in the chain thus allowing motion. Safety measures include a brake system comprised of cables, levers and caliper system. A seat post suspended on the seat-tube bears a seat upon which the rider seats in comfort.
Technical Explanation of Components
Brake levers re simple wire constructs enabling the rider to control the speed of the machine via braking. A lever suspended on the handle-bar allows the user to apply pressure (the brake lever) hence retarding the motion of the bicycle. This happens by pressing on the metallic bicycle rim. Forward motion of the machine is achieved through muscle power for the main part as the rider applies pressure on the peddles which in turn cause the chain to propel the wheels. Latter versions of the machine possess additional gear systems such as the derailleur and these allow for the application of minimal or maximal force for motion.
The wheel section of the bicycle comprises of a spoke system where a central hub sends out metal spokes to the rim. The system allows for greater wheel strength as the spokes distribute the weight of the rider along the rim while in action. While early versions of bicycles differed little from modern versions, the popularity and spread of the machine only progressed through the invention of pneumatic rubber tires. This was because early versions of wheels tended to quickly erode due to friction.
Machine dynamics for the two-wheeled versions comprises of consistent motion allowing for balancing. The rider’s mass is centrally located over the frame of the bicycle and through perpetual forward, throws the mass of the rider and machine forwards thus preserving balance. Directing the machine is achieved by turning the handle-bars which in turn direct the front wheel of the machine towards the preferred position. However, turning is limited to certain factors such as speed, aerodynamics and mass as physical forces prevent tight turns. According to researchers, top speeds of 83mph have been recorded among professional riders.
Bicycles are feats of aerodynamic engineering in that they are the fastest form of muscle powered motion man ever designed. Only gliding or wind-sail-boating achieves greater speeds. Additionally, if one were to factor the adaptability to land terrain that bicycles possess, they automatically supersede even most forms of mechanical and chemical powered machines such as planes and automobiles because of their ability to traverse most terrains. Bicycles are light-weight and simple in design thus not only portable but easily assembled. Ultimately, they are environment friendly thus do not present the same danger posed by nuclear or fossil fuel energy.