Tour de France is most well-known bicycle race, which has existed for over 100 years. The race covers more than 2200 miles in a 23 day course covering France and other neighboring countries. It is a test of endurance and skills of bikers as well as most technologically advanced racing cycles used by them.
Racing bicycles are designed for only one purpose – to go fast. To achieve this feature they must have light weight, so that cyclist don't need to put in more efforts for propelling the bicycle. Along with this, aerodynamic of the bicycle also contributes to its speed. With the combination of both these features, cyclist can attain maximum speed within the required time.
Weight of every component of bike is an important criterion to be considered. Manufacturers make the design as light as possible to attain faster speed. For example, aluminum alloy, a lightweight material is used to make wheel rims. Some bicycles have rims made of carbon fiber, which is more light. To achieve higher aerodynamic efficiency, rims have triangular cross-sections and wheels of bicycle have few spokes. Again, the tyres of bicycles are narrow, lightweight and have smooth, thin thread. Tyres are inflated at a very high pressure to increase the potential speed of the bike.
All the mechanical components of a racing bike excluding the frame, bars, stem, pedal, saddle, seat post and fork are referred as “groupset”. Derailleur gear is an essential part of a groupset. It include chain, wheels with teeth and a mechanism that shifts chain from one to another sprocket. It is this system, which allows cyclist to adjust the speed according to the terrain.
There are large number of manufacturers who produce complete bicycle, while others assemble different parts together. Every company has different design and technique, which makes one or other cyclist loyal to the brand.