An aluminum racing bicycle made by
Raleigh and built using
Shimano components. It uses a semi-aerodynamic wheelset with low spoke count.
A racing bicycle is a bicycle designed for road cycling according to the rules of the Union Cycliste Internationale (UCI). (Bicycles for racing indoors are track bicycles; bicycles for racing offroad are mountain bicycles or cyclo-cross bicycles; bicycles that race according to the rules of the International Human Powered Vehicle Association are recumbent bicycles.)
The two most important things about a racing bicycle are its weight and low aerodynamic drag (at least as far as can be achieved within the rules of the UCI). Everything else in the design is sacrificed for these properties. In order to reduce wheel weight and improve aerodynamic efficiency, racing wheels have fewer spokes than non-racing bicycles, or are made of moulded fibreglass, carbon fibre, or aluminum. The resulting weaker wheel is not suitable for carrying heavy loads or landing from jumps, since this could cause spokes to break. To reduce both air resistance and friction on the road, tires are thin and smooth, and pumped to a very high pressure. Most racing bikes use "tubular" tires which are glued to the rims, instead of the heavier clincher tires found in most bicycles. However, while training most cyclists prefer clinchers because they can be patched on site if they have a leak. Drop handlebars and optional handlebar extensions are combined with a raised seat post in order to put the rider in a more aerodynamic posture. The front and back wheels are close together so the bicycle can turn very quickly. The derailleur gear ratios are closely-spaced so that the rider can pedal at his or her preferred cadence.
Components are as light as possible. The fastest racing bicycles thus need a great deal of maintenance.
The UCI specifies [1] that a racing bicycle have the following characteristics:
- be a vehicle with a front wheel steered by a handlebar and a rear wheel driven by a system comprising pedals and a chain by the legs moving in a circular movement
- wheels must be of equal diameter, between 70 cm and 55 cm, and must have minimum 12 spokes
- maximum length 185 cm
- maximum width 50 cm
- the peak of the saddle must be at least 5 cm behind a vertical plane passing through the bottom bracket spindle
- the saddle must be between 24 cm and 30 cm in length
- the distance between the bottom bracket spindle and the ground must be between 24 cm and 30 cm
- the distance between the vertical passing through the lower bracket spindle and the front wheel spindle must be between 54 cm and 65 cm
- the distance between the vertical passing through the bottom bracket spindle and the rear wheel spindle must be between 35 cm and 50 cm
- the maximum internal distance between the front fork ends is 10.5 cm, and of the rear stays 13.5 cm
- minimum weight 6.8 kg
- frame must be built around a main triangle, constructed of tubular elements (that may have non-circular cross-sections) such that the form of each encloses a straight line
See also
