Racing bike
A racing bike (Switzerland Rennvelo ) is a bicycle that was designed for use as a sports device in road cycling . It is characterized by a lightweight construction and the reduction to the parts required for driving (i.e. no luggage racks, mudguards, lighting, etc.).
technical features
general characteristics
Today's racing bikes usually weigh between 8 and 9 kg. According to the UCI regulations, a minimum weight of 6.8 kg must be observed for competition bikes. The lightest racing bike ever used in a UCI race was Eddy Merckx's time trial machine , with which he set a world hour record in 1972 . It is a track bike with a lugged steel frame by Ernesto Colnago and weighs 5.75 kg. However, there is already a design study in which a racing bike weighing less than 3 kg was realized. The extent to which this model can be driven under racing conditions is controversial.
With the regulation change from 2000 (definition of the term racing bike), the UCI set a racing bike like the one used by Merckx as the standard for world hour record attempts (i.e. handlebars, saddle tip behind bottom bracket, etc.) and canceled all records from the 28 previous years.
The UCI argues that in an arms race for a technically optimized bicycle, poorly equipped athletes or cycling associations would fall by the wayside.
The usual today racing bikes have very narrow rims and tires , a racing wheel, the so-called strap link or horn handlebar , the various grip positions allowed and is narrower than usual chassis (UCI regulations are max. 50 cm permitted, are rarely wider than 44 cm used). The width of the handlebar (measured from the center of the pipe to the center of the pipe, usually at the ends of the pipe, sometimes at the foremost point of the pre-bend; the total handlebar width from outer edge to outer edge is rarely specified) depends on the rider's shoulder width (measured from the outside to the outside of the shoulder bones ) and should roughly correspond to this. Randonneurs tend to use slightly wider handlebars (more control, chest wider), competition riders tend to use slightly narrower handlebars ( more aerodynamic seating position, less space required in the peloton). For aerodynamic reasons, special handlebars or handlebar attachments for conventional bow bars are used in triathlons and time trials , in which the driver rests with his forearms and grabs forward with his hands. In order to make ergonomic sense, however, a special geometry of the frame is required (steeper seat angle).
Racing bikes have no luggage racks and no mudguards, and no mounts on the frame and fork provided for them. They basically do not have permanently mounted lighting devices and dynamos. As a rule, one or two holders for drinking bottles are mounted on the down tube and seat tube.
Brakes
Cable-operated rim brakes are mainly used. Hydraulic rim brakes and especially disc brakes - in contrast to mountain biking and cross-country sports - are currently given little weight in road races, and the sharp edges of the brake disks can pose the risk of cuts in the event of a fall. Recently, however, racing bikes with disc brakes have increasingly been offered; Disc-braked bikes were also used for the first time at the Tour de France 2017 , after they were approved by the UCI. Campagnolo's Delta brakes, popular in the late 1980s, offered better braking performance than the single-joint side-pull brakes of the time, but were difficult, complicated to maintain and required greater operator force.
circuit
In racing bikes usually come chain circuits for use in professional racing bikes with 2 x 10 or 2 x 11 courses, recreational wheels with three chain wheels at the front and 8 to 10 sprockets rear. Campagnolo has been running a gearshift for 12 rear rims since 2018 (Campagnolo Super Record cassette 12-speed). SRAM followed in 2019 with the introduction of its own 12-speed group (Red eTap AXS). So-called compact cranks have been increasingly used since around 2003 . Here the two chainrings at the front are a bit smaller (50 and 36 or 34 teeth instead of 53 and 39 teeth). They also allow small gears to go uphill, but are quicker to shift and lighter than systems with three chainrings, which also require special gear levers, a rear derailleur with a longer cage and a longer chain. In addition, compact cranks with two chainrings have fewer gear overlaps, i.e. you have fewer “double gears” (chainring / sprocket combination with the same gear ratio) and they retain the typical racing bike look that you are used to from professional bikes.
Shift and brake levers have been customary as integrated units for some years, especially since the introduction of indexed shifting, while in earlier models the shift levers were arranged on both sides of the down tube of the frame. With integrated brake / shift levers, the gear change is carried out with a lateral deflection of the brake lever (by finger pressure on the outside) and / or with a smaller release lever located behind the brake lever, with one unit acting on the derailleur and one on the rear derailleur. For reasons of weight, some cyclists use frame shifters for the less frequently used front derailleur during mountain time trials . In the meantime, several manufacturers also offer electronic gears without mechanical cables, in which the front derailleur and rear derailleur are motor-driven.
frame
The classic diamond frame has established itself in normal road machines and is also prescribed by the UCI regulations. With time trial machines and record bikes, there is a little more freedom, but here too, if the bike is used in a competition or a record run is to be officially recognized, the frame must “show the shape of a triangle.” These provisions are intended to create equal opportunities, however it is also argued that they prevent innovation.
Many manufacturers now offer special frames for women. These usually have a shorter wheelbase and / or steeper seat tubes.
Outside of the UCI regulations, e.g. B. in the triathlon area, free constructions up to monocoques made of composite materials are used.
As frame materials find steel , aluminum , carbon and titanium use, all of these materials have both advantages and disadvantages. Combinations of several materials, such as carbon fiber reinforced plastic (CFRP; colloquially carbon) and titanium, are just as common as the use of special materials or alloys ( magnesium , V4A, scandium (an aluminum alloy with a low proportion of scandium )).
The table below lists the advantages and disadvantages of the specific materials used in discussions. However, details are controversial.
| Frame material | advantages | disadvantage |
|---|---|---|
| steel |
|
|
| aluminum |
|
|
| Carbon fiber reinforced plastic ("carbon") |
|
|
| titanium |
|
|
A normal diamond frame can also give way to the side, which requires a low torsional stiffness in order to create a suspension. But it is precisely this that also determines the driving stability, especially on descents. Each frame material has advantages as well as disadvantages. Light frames often have low steering head and bottom bracket stiffnesses. The first reduces driving safety, the second the efficiency of pedaling.
In addition to the total weight, special attention is paid to reducing the mass of the rim and tires . Due to the rotation , its mass is almost doubled in the acceleration work .
Frame size and seating position
The wheelbase of a racing bike is generally 940 to 1070 mm with frame heights of 51 to 64 cm. For women, modified frame geometries are offered, which are intended to meet the female requirements for relaxed sitting. In fact, most women drive “normal” geometries. Basically, a frame geometry that is adapted to the body dimensions of the cyclist must be selected so that the physical performance can be implemented. In special cases (extreme deviations in body measurements from the norm) this goes as far as the custom-made frame. Special cycling disciplines require modified frame geometries. So have z. B. Criterion, track and post frames have a shorter wheelbase and 2.5 - 5 mm shorter cranks and a slightly higher bottom bracket .
The saddle is adjusted horizontally and is higher (usually 4 to 15 cm) than the handlebars, this is referred to as superelevation . The tip of the saddle on road racing bikes is about 5 cm to 10 cm - depending on the rider size and leg length - behind the vertical through the bottom bracket axle. To determine the optimal seat height, i. H. There are different methods for measuring the distance between the top edge of the saddle and the center of the bottom bracket, measured along the seat tube:
- There are tables and formulas that derive the seat height from the leg length.
- A practical, although only approximate method says: If you are in a comfortable position on the saddle and without tilting your hips, your heel should just touch the lowest point of the pedal with your leg outstretched. However, there are variables here, because both the height of the pedal and, if necessary, the binding system as well as the sole thickness or heel height of the shoes must be taken into account. There is no binding norm for the driving position, only ergonomic factors, so a precise, performance-optimized setting can only be made by a specially trained trainer. Many criteria, e.g. B. the driving style (calm or rather restless), the cadence (strength-oriented or frequency-oriented), training and health status (spine!) As well as external factors such as route profile and length etc. must be taken into account.
- In the meantime there are also online calculators that calculate the frame size. Some of them are offered by online retailers, some by independent operators.
The seat length is determined in a similar manner, i.e. H. the distance between the tip of the saddle and the center of the handlebar tube:
- Here, too, there are calculation formulas that take body size, torso length and arm length into account.
- The practical rule says: The handlebar stem as a variable size is selected so that the distance from the saddle nose to the center of the handlebar tube corresponds to the length of the forearm (from the tip of the elbow) including the middle finger of the outstretched hand plus three to five finger widths. The stems of racing bikes are significantly longer than those of other types of bicycles - since the frames are on the one hand shorter and on the other hand an aerodynamically flat position is to be assumed, the necessary distance between the handlebars and the saddle must be established in this way.
Even for normal people, these rules are only guidelines. The driver usually only finds the final seating position after extensive tests and, as mentioned above, through the observation of experienced trainers. Small corrections of a few millimeters are useful for competition-oriented cyclists.
Impellers
Road bikes are predominantly used with 28-inch wheels with a nominal rim diameter of 622 mm. Because racing tires are narrower and lower than standard 28-inch tires, the actual outside diameter of the tire is less than 27 ". Special criterion wheels can also be smaller (e.g. Eddy Merckx ). In the triathlon sector, 26 "wheels with a rim diameter of 571 mm were common for a long time. In contrast to the newer ETRTO dimensions, the inch specifications are not clear. 26" wheels on mountain bikes and everyday bikes, for example, generally have a nominal rim diameter of 559 mm.
Over time, the shape of the rim has also changed. For a long time, rims with a slightly rounded rectangular profile, so-called box rims, were common. These are replaced by high-profile rims, which are particularly stiff but also a little heavier. Disc wheels are also often used in time trials . Flattened knife spokes can also further reduce air resistance. However, the effect is small and can only be measured at speeds above 40 km / h.
27 "is larger than 28"
Paradoxically, 27 "rims with 630 mm have a larger ETRTO nominal diameter than 28" rims with 622 mm (1 inch = 25.4 mm). 28 "rims were originally designed for much thicker tires than the 27" rims intended for cycling. The outer diameter of the impellers is therefore, for example, as follows:
630 mm Felge + 2 × 28,0 mm Reifen = 686 mm = 27" 622 mm Felge + 2 × 44,5 mm Reifen = 711 mm = 28"
In fact, 28 "wheels with the 23 mm tires commonly used on racing bikes only have a diameter of between 665 and 675 mm:
622 mm Felge + 2 × 23 mm Reifen = 668 mm = 26,3".
Tires
In the past, road bikes with tubular tires were used. Today they are mainly only used in professional sports and cyclocross . Clincher tires are becoming increasingly popular. A variant of the clincher tires are folding tires . These have flexible Kevlar threads instead of the rigid wires incorporated into the tire beads, which allow space-saving folding and easy transport of a replacement jacket, for example. B. allow under the saddle frame. Folding tires are usually lighter and are offered by the manufacturers as an altogether higher quality alternative to clincher tires.
The particularly narrow racing bike tires are also jokingly called dachshund cutters among racing cyclists . The term possibly goes back to a gloss by Jörg Spaniol in the cycling magazine Tour . These tires with a width of 18 to 20 mm (compared to the standard width of 22-24 mm) were very common on racing bikes in the 1990s.
Translations
Advances in technology - above all ever narrower chains that allow a higher number of sprockets - has caused the variety of gear ratios on racing bikes to skyrocket in the last two decades. While in the 1980s the 6-fold cassette had just replaced the 5-fold cassette, in the 1990s the 7-fold, then the 8-fold cassette, followed in quick succession at the end of the 1990s, the 9- compartment and 10-compartment cassette followed. Campagnolo has been offering the 11-speed cassette since 2009, Shimano since 2012 and SRAM since 2013 . The 12-speed cassette has been on the market since 2018 (Campagnolo), SRAM followed in 2019.
Even the triple equipment for the chainrings, originally attributed to trekking and mountain biking, found its way into racing bikes in the hobby class. Thus, in just a few years, the number of theoretically possible translations has risen to a maximum of 30.
Despite the triple chainring set that has now been used, the double equipment with a 53 and a 39 chainring is now standard from beginners to world-class professionals. Combined with the frequently used 10-speed cassette with pinions from 11 to 21 ( 11-12-13-14-15-16-17-18-19-21 ), this equipment offers a range of ratios from 4.7: 1 to 1 , 85: 1. Due to an overlap area, which theoretically ranges from 53/16 or 39/11 to 53/21 or 39/15, there is sufficient variety in hectic racing situations in the short term to avoid double gear changes, while excessive chain skewing that increases wear can occur in the long term be avoided.
The so-called compact cranks with 50 teeth on the large and 34 teeth on the small chainring are enjoying growing popularity among amateur athletes .
Common translations for amateurs and professionals are:
- In training : cadence-oriented 39/15, normal range 53/18 to 53/15, on the mountain according to the requirements for performance level, training goal and inclination in relation to the preferred cadence level;
- in the race : 53/16 to 53/14, with catch-up attempts , escape attempts and the like up to 53/12, on the mountain 53/19 or according to the incline on the 39 chainring.
In particularly mountainous races, it is advisable to do without gear ratios in the middle range. For example, cassettes with 12 to 25 teeth ( 12-13-14-15-17-19-21-23-25 ) are commercially available.
Variants and subspecies of racing bikes
There are a number of modifications of racing bikes, which essentially have many features of the racing bike defined by the UCI, but are optimized for the specific purpose. Most of these bikes look like racing bikes because of the handlebars. These bikes are not suitable and not approved for classic bike races (tours and classics).
- Triathlon bike , with specially adapted aerodynamics and strongly bent seating position ("triathlon handlebar") for triathlon races with no slipstream
- Time trial machines, optimized aerodynamics for individual time trials, often with a disc wheel at the rear
- Track bike , with fixed gear without gears and brakes for track races
- Cyclocross bikes (cyclo-cross bikes ), also known as crossers , robust racing bikes with more voluminous and profiled tires for cross-country races and other braking technology. Lately these bikes are called gravel bikes .
- Randonneur (or randonneuse), special racing bike for long distance rides , sometimes with mudguards, lights and a small luggage rack
- Half-runners , often also called speed bikes , fitness bikes or flat bar racers , racing bikes with straight touring or MTB handlebars instead of racing bars
Legal definitions
Austria
The Austrian Bicycle Ordinance defines a racing bike as follows:
§ 4 (1) A racing bike is a bike with the following technical characteristics:
- Dead weight of the ready-to-ride bike is a maximum of 12 kg
- Racing handlebars (but this is not precisely defined)
- External rim diameter at least 630 mm
- Outer rim width not more than 23 mm
Strictly speaking, only bicycles with tubular tires are recognized as racing bikes in Austria, in practice clincher tires are also accepted, which makes point 3 ad absurdum.
Germany
In Germany, the racing bike was only mentioned in the road traffic licensing regulations in connection with lighting systems on bicycles. It was not defined there. For racing bikes weighing up to 11 kg, one or more batteries could be carried instead of the alternator to operate the headlights and tail lights, the headlights and the mandatory tail lights did not have to be permanently attached to the bike, the headlights and tail lights did not have to be switched on together, and a headlamp with a nominal voltage lower than 6 volts was allowed to be carried.
This regulation became less and less applicable as dynamo lights with battery support did not fit into this definition. The 2017 paragraph was therefore adjusted.
In principle, a racing cyclist must also comply with the duty to use the cycle path, unless their use is unreasonable, if they are in an improper and therefore unreasonable condition. That means: Snow / leaves not cleared, heavily soiled, blocked up / parked, construction site etc. This restriction applies to all cyclists. However, this interpretation is very flexible and therefore a matter of interpretation.
Basically, according to the Road Traffic Regulations (StVO), cycle lanes only have to be used if the corresponding sign “Sign 237”, ie a white bicycle on a blue background, is present. Otherwise the road may be used.
Paths marked with “Sign 240” and “Sign 241”, ie where a bicycle is shown in combination with pedestrians, must also be used.
This duty of use applies formally to all cyclists, regardless of whether they use a city bike or a racing bike.
There are exceptions to this rule nationwide for closed associations of 16 and more cyclists ( § 27 I 2 StVO), they are generally allowed to drive on the road and in rows of two and in some regions / cities for cyclists who have a competition license from Federal German cyclists have.
In the StVO amendment 2020 it was made clear that cycling side by side is generally permitted. Only when other road users are obstructed do you have to drive in a row.
literature
- Steve Thomas, Ben Searle, Dave Smith: The Big Road Bike Book. Training, technique, tactics. Delius Klasing Verlag, Bielefeld 2009 (4th revised edition), ISBN 978-3-7688-5281-4 .
- Michael Gressmann: Bicycle Physics and Biomechanics. Technology, formulas, laws. 11th edition, Delius Klasing Verlag, Bielefeld, 2010, ISBN 978-3-7688-5222-7
- Rüdiger Bellersheim, Ernst Brust, Michael Gressmann, Dietmar Hertel, Franz Koslar: Bicycle technology table book , European teaching materials; 2nd edition 2011, ISBN 978-3-8085-2332-2
- Dirk Zedler, Thomas Musch: The racing bike workshop. Delius Klasing Verlag, Bielefeld 2010 (9th revised edition), ISBN 978-3-7688-5311-8 .
- Guy Andrews: Road bike. Maintenance and repair. Delius Klasing Verlag, Bielefeld 2011 (2nd edition), ISBN 978-3-7688-5296-8 .
- Dirk Zedler, Thomas Musch: Build your racing bike yourself. Delius Klasing Verlag, Bielefeld 2006 (3rd edition), ISBN 978-3-7688-5243-2 .
Web links
- Website of the BDR ( Association of German Cyclists )
- Cycling website "Active cycling"
- Smolik Velotech
- Adjust bike
- Saddle height and sitting position when cycling
Individual evidence
- ↑ Projekt_2,96 by Günter Mai ( Memento from February 17, 2010 in the Internet Archive )
- ↑ Calculator for racing bike frame geometry depending on body dimensions ( Memento from April 7, 2017 in the Internet Archive )
- ↑ Disc brakes on racing bikes: We clarify the facts , report on roadbike.de from April 19, 2017
- ↑ Disc brakes at the Tour de France - First victory thanks to Marcel Kittel , report on tour-magazin.de from July 2nd, 2017
- ↑ Hilite Pinion racing bike
- ^ Christian Smolik , Stefan Etzel : Bicycle Lexicon. Technology, material, practice from A - Z 2008, ISBN 9783870734336 , p. 205
- ↑ cf. Information from the UCI on the application of the regulations for racing bikes ( Memento of August 9, 2009 in the Internet Archive ) (English / French)
- ↑ Gunnar Fehlau: 1000 tips for bikers, ISBN 3-89595-156-0
- ↑ a b Smolik Velotech: frame load
- ↑ Winkler / Rauch: Fahrradtechnik , Delius Klasing, ISBN 3-87073-131-1
- ↑ Etzel, Smolik: Fahrradlexikon , BVA, ISBN 3-87073-433-7
- ^ Christian Smolik: The new bicycle repair book , BVA, ISBN 3-87073-055-2
- ↑ § 67 StVZO
- ↑ https://radverkehrspektiven.de/stvzo-endet-helles-licht-am-fahrrad/
- ↑ https://www.gesetze-im-internet.de/stvzo_2012/__67.html
- ↑ BMVI - We are making road traffic even safer, more climate-friendly and fairer. Retrieved July 12, 2020 .