Racing bicycle

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, cyclo-cross bicycles or cycle speedway bicycles; bicycles that race according to the rules of the International Human Powered Vehicle Association include recumbent bicycles which are the fastest bicycles in the world.) Recumbents were excluded from the definition of a bicycle on 1 April 1934.

Related Topics:
Bicycle - Road cycling - Union Cycliste Internationale - Track bicycle - Mountain bicycle - Cyclo-cross bicycle - Cycle speedway - International Human Powered Vehicle Association - Recumbent bicycle - 1 April - 1934

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The two most important things about a racing bicycle are its weight and the aerodynamic efficiency of the rider's position. Drop handlebars and optional handlebar extensions are combined with a raised seat 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 optimum cadence.

Related Topics:
Aerodynamic - Handlebar - Derailleur gear - Cadence

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The wheelset greatly affects the performance of a racing bike. The wheels rotate at high speeds; consequently their moment of inertia matters a lot. The rim of the wheel can be shaped for greater aerodynamic efficiency making a triangular cross-section to form a teardrop with the tire. For hillclimbs, however, effects from weight overcome those from aerodynamics, and the traditional box-sectioned rim is often used.

Related Topics:
Wheelset - Moment of inertia

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For aerodynamics and rotating weight, it is generally better to reduce the number of spokes in the wheel. For high-end wheelsets, the spokes can be shaped to have a bladed cross-section, further reducing wind resistance.

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The most common material for a wheel rim is aluminium alloy. Using a molded carbon fiber rim reduces weight compared to a metal rim. Using exotic materials, race-grade wheelsets are very expensive. Riders may choose to switch to cheaper and heavier wheels for training; some of the lightest wheelsets are relatively fragile, but most problems occur when a tire is punctured and the carbon rims are rolling on the tar-mac, which chips,cracks and recks these expensive wheelsets.

Related Topics:
Aluminium - Carbon fiber

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To reduce both air resistance and friction on the road, tires are thin and smooth, and inflated to high pressure, typically around 120PSI / 820kPa; racing specific tires can run upwards of 210PSI. Until recently, most racing bikes used "tubular/single/sew-up" tires which have no beads: they are sewn around the tube and glued to the rim. These tires provide an advantage in both rolling resistance and grip, but advances in tire technology have seen the far more practical clincher (beaded) tire close the gap. Some manufacturers create Tubular-Clincher tires, where the tires are sewen around the tubes and have a bead, all the advantages of a Tubular tire made to fit a clincher rim.

Related Topics:
Friction - PSI - KPa

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Race bike componentry (excluding frameset, fork, wheelset, bars, stem, pedals, seat and seatpost) is collectively referred to as the groupset. The quality of the groupset determines how refined the bike feels, how much maintenance it requires, and contributes to the performance of the bike. The two major groupset manufacturers of complete groupsets for racing bicycles are Shimano and Campagnolo. The companies have different design philosophies, and some cyclists have great brand loyalty for one or the other. Other companies that produce individual components, but not whole groupsets include Full Speed Ahead (FSA) and SRAM.

Related Topics:
Groupset - Shimano - Campagnolo - Full Speed Ahead - SRAM

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In the early 1990s, Shimano introduced dual-control a system called Shimano Total Integration (STI). STI is characterized by its combined brake and shift levers, or "brifters". Previously, the shifters were mounted on the stem or the down tube of the frame. Dual control addressed the problem of having to reposition a hand to change gears. STI was followed by the competing Campagnolo/Sachs Ergolever. Other than this, the general design of a racing bicycle has changed little since the development of derailleurs.

Related Topics:
Shimano - Shimano Total Integration - Shift levers - Campagnolo - Ergolever

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In the mid 1990s Mavic, known for their wheelsets, introduced an electronic shifting system which was pioneered in the Tour de France by American Greg LeMond. The system did not catch on due to technological hurdles, but it has been rumored that Campagnolo has been developing an electronic groupset and has been field tested as recently as the 2005 Giro d'Italia.

Related Topics:
Mavic - Tour de France - Greg LeMond - Giro d'Italia

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For recreational cycling, the racing bicycle is less popular than the mountain bike. Mountain bikes, through mass production and popularity, are less expensive. A new entry-level mountain bike starts around half the price of an entry-level racing bike.

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Racing bikes are less durable and less strong than mountain bikes. But unless a rider intends riding on rough tracks a racing bike is more efficient for everyday use. Cyclo-cross bikes, which are ridden off-road, are closer to racing bikes than to mountain bikes. They have wider, treaded tires and cantilever brakes instead of caliper brakes but are still less efficient than racing bikes for use on the roads.

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The UCI rules (rewritten in 1934 to exclude recumbent bikes which had recently captured the world speed record) specifiyhttp://www.uci.ch/modello2.asp?1stLevelID=C&level1=1&level2=14&idnews=2443 that a racing bicycle have the following characteristics, :

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• 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
 
Racing bicycle: See also ►