Bicycle brake

Function of a rim brake

Stamp brake on a Laurin & Klement bicycle (1890), exhibited in the Škoda Muzeum

Drawbar brake (inner rim brake) for front and rear wheel

Rod-operated drum brakes for the front and rear wheels on a Dutch bike from 2009

A bicycle brake is a device that can be used to brake the journey of a bicycle . With the first bicycles, the front wheel was driven directly with the crank and could therefore also be braked (see: History of the Bicycle ). With the introduction of the freewheel hub at the latest , the brake was part of the standard equipment of the bicycle. A large number of different versions were created, of which the cable-operated V-brake has been the most common since the turn of the millennium.

The brake lining is in the padding and rim brakes directly to the tire or the rim is pressed, in the drum or disc brake on a separate friction surface with the hub is connected so that the spokes the braking torque to the wheel must be transferred. The brake lining is pressed against the friction surface in the case of shoe and drum brakes radially and in the axial direction in the manner of pliers in the case of disc and rim brakes.

Statutory Regulations

According to the German Road Traffic Licensing Regulations (StVZO), bicycles must have two independent brakes in accordance with Section 65 StVZO.

The Austrian Bicycle Ordinance also requires two independently acting braking devices. On a dry road, these must achieve an average braking deceleration of 4 m / s² at an initial speed of 20 km / h.

In Switzerland, according to Art. 214 (2) of the Ordinance on the Technical Requirements for Road Vehicles , bicycles must be fitted with two powerful brakes, one of which acts on the front wheel and the other on the rear wheel.

In DIN EN ISO 4210-2, a braking distance of no more than 7 m from 25 km / h is required for everyday bicycles. This corresponds to about 3.5 m / s². With regard to product liability , the minimum requirement for bicycle brakes in accordance with Directive 2001/95 / EC on general product safety is DIN EN ISO 4210-4 (safety requirements for bicycles - test methods for brakes).

Braking effect and safety aspects

Dynamic wheel load distribution: The effect of the dynamic wheel load distribution caused by braking causes the weight force to be redistributed from the rear wheel to the front wheel. In the worst case, the rear wheel might lift off and the bike might roll over. As the weight on the rear wheel decreases, its static friction with the road surface decreases. This means that the rear wheel locks when the braking force is low. The effect is reinforced by a sloping road (shifting the center of gravity forward) or additional dynamic weight shifting through uneven road surfaces such as potholes.

The shorter the wheelbase and the further forward and higher the center of gravity, the more pronounced are the effects of dynamic wheel load distribution when braking.

Locking the wheels: The wheels can lock depending on the condition of the road surface and the amount of braking force. Blocking the front wheel, in particular, often leads to a fall, as the bike can then no longer be steered or balanced (see dynamics of cycling ). To avoid locking the front wheel, always use the rear brake on slippery surfaces.

Braking force: When it is wet, brakes with an unprotected friction surface must first displace the water film and allow it to evaporate before they can develop their full braking force . However, this is particularly noticeable with rim brakes in combination with steel rims. The contamination of the friction surfaces can affect braking friction and wear .

In the case of cantilever brakes, the braking force is heavily dependent on the course of the cables and, in this respect, both on the setting of the brake and on the thickness of the brake pads. Historical bicycle brakes, for example the punch brake or side-pull brakes with steel rims, usually no longer meet today's demands with regard to the braking effect.

Dosability: Brakes that can be applied sensitively increase safety. The prerequisites are high-quality brake cables with little compressibility and frictional resistance or, alternatively, hydraulic brake systems.

Stability and overheating

Most bicycle brakes are not suitable for long, sustained braking with high braking force. If by friction in heat converted kinetic energy is not delivered sufficiently to the environment, brakes can be very hot. This can lead to different problems depending on the type of brake.

Overheating of the brakes typically occurs on long descents in high mountains. With loaded transport and touring bikes as well as with tandems , this can happen even on shorter descents. As a preventive measure, brakes should be installed that have been expressly approved by the manufacturer for use with tandems, cargo bikes or for downhill use on mountain bikes .

There are various ways to relieve the brakes on long descents:

There is no need to brake on a safe and manageable route. The speed then increases until the air resistance is great enough to prevent further acceleration (the air resistance increases by the square of the speed). An upright posture reduces the maximum speed that can be achieved.
The driving speed is reduced so much that the cooling caused by the wind and radiation limits the heating of the brakes to an acceptable level.
Occasional breaks are provided to allow the brakes to cool down.
Additional brakes are installed that have their own cooling surfaces. (The installation of a second rim brake on the same wheel increases the braking force, but only minimally reduces the heating of the rim, since all brake pads heat the same cooling surface .) With travel tandems it is common to install a third brake, which is heat-resistant and on longer ones Downhill runs can be locked in the tightened state.
Manufacturers of disc brakes recommend alternately applying the brakes on long descents or letting the bike roll without braking at short intervals instead of constantly applying both brakes ("drag braking"). When the brake is released, air enters the gap between the brake pad and disc and cools the brake pad, which is otherwise hardly reached by the cooling airflow. When using brake pads with special lateral cooling surfaces, intermittent braking is usually not necessary.

= Typical consequences of overheating

In particular, disc brakes with discs that are too small (e.g. with a diameter of 160 mm) can lose a lot of braking power on long descents due to the formation of boiling bubbles.

Typical overheating problems with hydraulic disc brakes

The frictional heat is transferred from the thin brake lining via the cylinder relatively directly to the brake fluid, which is then boiled. This can drastically reduce the braking power, as the bubbles first have to be compressed when the brake lever is operated. For prevention, the cooling of the brake is improved by using larger brake discs and brake pads with cooling fins.
The heating of the brake caliper can lead to softening and failure of the plastic brake line. This can be remedied by using cables with an outer metallic fabric (so-called steel flex cables ).
Excessive heating can lead to lateral deformation of the brake disc . The lateral runout can be reduced again by straightening (bending) the pane.

Drum brakes and coaster brakes heat up during prolonged braking heavily on, resulting in reduced braking force ( Fading leads). A total failure does not usually occur. With coaster brakes and roller brakes , the grease in the hub can liquefy and leak, coke or evaporate. In the past, the hub could easily be re-greased yourself using the oiler it contained .

Due to the larger (cooling) surface of the rim, rim brakes heat up less. When using tubular tires, however , the heating of the rim can soften the tire cement and cause the tire to peel off. The warming of the hose and jacket makes them a little more susceptible to tire damage.

Brake types

For the newly developed brake types cantilever , V-brake and U-brake , English-language names have established themselves. In this article, the German terms V-Bremse and U-Bremse are used alternately .

Punch, pad and spoon brake

Block brake

A rubber block is pressed onto the tread of the tire using a simple lever mechanism with the block brake , also known as the ram brake . The braking effect is low and is strongly influenced by the condition of the tire (air pressure, moisture, dirt). The wear on brake pads and tires is also quite high. Later block brakes are operated by means of a Bowden cable . This saved weight and made it easy to combine with any handlebar shape.

On English bicycles, a metal plate was often pressed onto the tire instead of the rubber block. In order to prevent damage to the tire by the steel edges, the edges of the plate have been bent upwards, whereby the appearance of a spoon brake (engl. Spoon brake ) gave.

Block brakes were already used on the original high-end bikes , although the solid rubber tires meant that wear and the condition of the tires were not that important. In addition, sharp braking was not possible at that time due to the high center of gravity of the bike.

Despite inadequate effectiveness, the simple block brake was adopted on the safety bike that came up later . In most cases, it then only served as an additional brake for the more reliable coaster brake. Only sports and racing bikes that were driven at high speeds were equipped with more effective rim brakes. This was the state of the art until the 1950s . The improving road conditions made it possible to drive faster, and the denser traffic in large cities required better brakes. In the FRG , the rim brake prevailed in the 1960s, in some other countries it happened a little later. In the GDR , the block brake was standard equipment on simply equipped bicycle models from Mifa and IFA Touring until the end of the 1980s. Today stamp brakes are only occasionally used on simple children's scooters and bicycles.

The previously common, wide bicycle rims often did not have sufficiently wide outer flanks running parallel to the surface, so that a different rim may have to be used for conversion to rim brakes.

Rim brake

Connection plate for attaching the rim brake and luggage rack

Side pull brake

Central pull brake - the shorter the cable running from left to right, the higher the braking force and the smaller the distance between the brake pads and the rim in the relaxed state

Brake based on the Para-Pull system from Shimano

Rim brakes were already used at the beginning of the development of the bicycle, as evidenced by the patent CH6896 from 1893 on a rod-operated rim brake. Had spread the inner rim brake (also strap brake , Eng. Stirrup Brake ). At the lower ends of the bracket that reached over the tire were the brake pads, which are pressed from below against the bottom of the rim when the brake is applied. In England, this design was used for utility bicycles with steel rims by some manufacturers (e.g. Raleigh ) until the 1970s. Since then, there have only been rim brakes based on the pincer principle, in which two opposing brake pads are pressed onto the side rim flanks. In the FRG, rim brakes became established in the 1960s, initially as side-pull brakes (single-joint brakes), replaced by cantilever brakes and finally as V brakes.

With rim brakes, a high and adjustable braking power can be achieved. Since the braking force is applied far out on the circumference of the wheel, the spokes, hub and frame parts are only slightly stressed during braking. Mechanical rim brake systems are comparatively light, uncomplicated and inexpensive.

The braking effect of rim brakes is less when it is wet than when it is dry. Since the braking effect depends on the material combination of the brake pads and the rim , care must be taken to use the correct brake pads. Brake pads for aluminum rims are often marked with "Alloy" ( Alloy stands for alloy , meaning here light metal alloy ).

The brake pads wear out much faster than drum and other hub brakes. To compensate for wear and tear, the Bowden cable must be re-tensioned regularly. Depending on the geometry of the brake, the brake pads wear more or less crookedly, which can usually be compensated for by adjusting the clamping or by turning the pads over.

The rim wears out when braking. In contrast to chrome-plated steel rims, the wear and tear on aluminum rims is so great that they can be regarded as wearing parts. The durability of simple aluminum rims is usually longer than that of brake pads and drive components such as chains and gears, but shorter than that of the bearings built into the hub and most other bicycle components. Since spoking a new rim is time-consuming, the entire wheel is usually replaced when the rim is worn. It is therefore advantageous to choose a rim made of a wear-resistant material or with a special coating. Coatings made from ceramic, for example, often require special brake pads, but they can greatly reduce wear and increase braking performance in wet conditions.

Modern aluminum rims are usually provided with a wear indicator in the form of a circumferential groove or point-shaped depressions, which become invisible when the rim is worn down to the bottom of the depression. In other designs, the markings or depressions only become visible when the surface is worn.

Traditionally, rim brakes were attached centrally to the fork bridge above the tire. With the exception of racing bikes, however, two-part systems predominate today, each with a fastening point on either side of the rim on the fork tubes or the seat stays. Newer systems are also offered with hydraulic actuation.

By shortening or lengthening the transverse cable pull, the ratio between the applied force and the resulting braking force can be varied with medium-pull and cantilever brakes. Theoretically, this is also possible by choosing the brake lever attached to the handlebar.

With some brake levers, the cable can be hooked into two positions in order to be able to reduce the lever arm for V-brakes (outer position) . With some handles, even a stepless adjustment is possible. The higher the resulting braking force, the smaller the deflection of the brake arms and thus the distance between the brake blocks and the rim. Simple rims often develop a side runout (they "egg"). In order to avoid dragging the brake, a lower braking force is then usually accepted in favor of a greater distance between the rim and the brake shoe. Since today's double wall rims are very stiff, this distance can in turn be reduced.

Brakes attached to the center of the fork and brake bridge

This version requires a through-hole in the middle of the fork bridge or in the case of suspension forks and on the rear end of the brake bridge, through which an M6 threaded bolt attached to the brake body is inserted. The screw connection is made with a hexagon nut or a sleeve nut. Until the 1990s, a so-called Pletscher plate was usually attached as a brake bridge , to which the luggage rack could be fixed in addition to the rear brake . Brakes attached to the fork or brake bridge have been the standard design on bicycles for decades. Since the turn of the millennium, these brakes have been used almost exclusively on nostalgic products ( retro wave ) and racing bikes .

The vertical distance between the fastening bolts and the center of the brake pads is called the brake dimension or the leg dimension . The adjustable braking dimension for classic racing bikes is between around 40 and 50 mm, for city bikes it is usually between 60 and 80 mm. The larger the braking dimension, the more complex the brake has to be designed to achieve the same braking force.

The (traditional) rim brakes are or were, among others, the following types:

Side pull brake: Both brake arms are mounted in the middle of the wheel on the fastening bolt like pliers. The actuating legs of both brake arms are arranged on one side so that a Bowden cable can be connected there on the side. Design-related weaknesses are the long lever arms of the brake legs, which require a correspondingly high operating force (manual force), as well as an asymmetrical grip when the spring tension is released.

Double-pivot brake, synchronized side-pull brake

Synchronized side-pull brakes

Nowadays (2016) of these types of brakes, only the dual pivot brake (double- joint brake ) - a synchronized side-pull brake - is used in racing bikes . The less effective and somewhat lighter side-pull brake is rarely used, known as a single pivot brake on racing bikes . The racing bike brake usually has a quick release of the brake cable in order to be able to open the brake shoes far enough when changing a wheel. The small braking dimension (leg dimension) between 40 and 50 mm enables powerful and stiff braking with small size and weight. Racing bike brakes are also available in a "long version" (long reach) with a slightly larger brake dimension.

Brakes attached to struts or fork shafts on both sides

On both fork blades or seat stays of the frame there is a brake base ("canti base"), which serves as the axis of rotation of the brake arms. When viewed from the side, the brake sockets for the U-brake are located further out than the rim flank, while the brake sockets for the cantilever and V-brakes are located below the rim flank.

Brake booster with mounting material

If the brake sockets are attached behind the fork shaft or seat stay, the brakes are more effective because the bending moments from the friction on the rim and the articulation of the lever arm cancel each other out.

A “brake booster” is a horseshoe-shaped bracket made of metal or composite materials, the ends of which are screwed onto the projection of the two brake sockets to stiffen them. The additional external connection of the brake pads reduces the torsion of the seat stays (or the fork shafts). With hydraulic rim brakes, the Brake Booster is usually already part of the system.

U-brake

The U-Brake ("U-Brake") is a center-pull brake with powerful brake arms and two suspension points which - seen from the side - are attached outside the rim diameter. There are also versions with a cable pull out at the side.

The U-Brake was used on mountain bikes from the 1980s. Mostly it was attached under the chain stays, which makes cleaning a bit difficult. The U-brakes were later replaced by the lighter cantilever and V-brakes. Since U-brakes do not protrude beyond the struts, they are still used in freestyle BMX .

Direct Mount Brake

The direct mount brake can only be found in racing bikes. This design was introduced by Shimano and other manufacturers in 2012. The direct mount brake can be designed in different ways (central pull brake, synchronous brake), but the common feature is a mounting standard in which the two axes of rotation of the brake arms are directly in threaded sleeves instead of being mounted on a base plate attached to the struts. The rear brake can also be installed under the chain stays. Compared to the traditional racing bike brake with a central attachment to the brake bridge, it is no longer possible to twist the brake body around the suspension point (e.g. due to different degrees of deflection of the two brake pads).

Roller cam brake

The principle of the roller cam brake in the form of a linkage brake has been known at least since 1899. In 1927 the Jeay brake (France) , based on the same basic principle, was patented. Charles Cunningham (USA) of Wilderness Trail Bikes (WTB) developed the Roller-Cam Brake from this design, to which he referred in the patent, in the mid-1980s . The Roller-Cam Brake sits on the same brake sockets as the U-Brake and, in principle, is also constructed in such a way that the actuating arms are not crossed. There are two grooved rollers at the point where the cable would otherwise attack. Between these guide rollers lies a slide plate ( cam ) that tapers upward in a curve-like manner . By pulling up the slide plate, the actuating legs of the brake arms are spread apart and the braking process is initiated. Suntour manufactured this brake under license for the then emerging mountain bike until the beginning of the 1990s . The roller-cam brake is problematic in terms of changing the wheel, adjusting the brakes and the risk of the freely suspended slide plate jamming or jumping out of the guide rollers.

In the 1980s, Shimano offered a comparable slide-operated racing bike brake with the Para Pull System .

Cantilever brake

Cantilever brake on cyclocross bike

“Low-profile” cantilever brake - the actual brake cable runs through the silver-colored sleeve visible on the right and is clamped by means of the screw at the end of the brake lever (“cantilever”). The sleeve is offered as a set together with the short piece of rope visible on the left and the coupling piece (not visible here) in various lengths. The shorter the short piece of rope and the sleeve, the flatter they run over the tire. The flatter this curve, the stronger the braking force and the smaller the distance between the brake pads and the rim in the relaxed state.

Cantilever is the English term for a cantilever arm and describes the two rocker arms of the brake that rotate around an axis. The axis sits on a base. One base is soldered, welded or glued to the left and right fork leg or the left and right seat stay. The placement and dimensions of the sockets are so consistent that they are suitable for all cantilever and V-brakes.

“Classic” cantilever design:
Came from around 1930 (“Cantilever” 1929 by Resilion, Nicola Barra 1936, “Speedy” cantilever 1938 by René Herse ), although this (and also the U-Brake) was already combined in 1904 French patent. Because conventional side-pull brakes, especially on cyclocrossers, touring bikes (randonneur) and tandems, did not offer enough braking force due to the larger distance between the pivot point on the fork bridge and the rim due to thicker tires and / or mudguards (poor lever ratio), the cantilever brakes moved the pivot point of the levers on the fork / seat stay below the rim. But it only became known with the advent of mountain bikes. Because of their sweeping design, they were replaced by the "low-profile" cantilever brakes in the early 1990s. This type, which was later also widely used in inexpensive bikes, dominated the market until the advent of the V-brake. It is only popular with cyclocross bikes.

Suntour SE XC Pedersen

Pedersen , also known as Self-Energizing Cantilever :
The brake arms are positively mounted on a multi -turn spindle with steep, groove-shaped threads, which are left-handed on the right brake arm and right-handed on the other. As soon as there is a frictional connection between the brake pad and the rim, the brake arm is pulled in the direction of rotation of the wheel and thus inevitably rotated on the spindle to the rim flank. As a result, a self-reinforcing braking effect is achieved.

This brake, patented by David Pedersen in the USA, was offered as "Scott-Pedersen SE" from the late 1980s. Suntour also had the Pedersen brake in its range, but only for the rear wheel. The brake was considered difficult to dose and was not a success. Production was stopped again. One indication of the failure of this brake is the premature abandonment of the patent due to non-payment of the patent fees.

V-brake

V-Brake / V-brake :
brand name of Shimano for a cantilever brake with transversely between the brake arms and verlaufendem in a bent tube guided upward inner cable. The term is often used for brakes of the same type from other manufacturers. General terms are Linear Pull Brake or Direct Pull Brake . V-brakes are easy and universal to assemble because, in contrast to classic cantilever brakes, no brake cable counter holder is required on the frame. The V-brake was available from Shimano from 1996. More complex versions have a lever parallelogram to guide the brake shoe in every position parallel to the rim flank. The principle of the Linear Pull Brake was used as early as 1988 by Keith Bontrager (USA) in the Kestrel Nitro or a little later in Germany by Florian Wiesmann. The basic features of the V-brake (and U-brake with a cable pull out at the side) can also be found in an English patent from 1938 .

The arm length of the V-Brake can be between 85 mm and 125 mm. Common designs have an arm length of 100 to 110 mm and are used with brake levers with a longer cable haul-up path (with a greater distance between the pivot point and the suspension point of the brake cable). V-brakes with arm lengths of less than 90 mm are called mini-V-brakes. Mini-V-brakes are used as well as classic cantilever or side-pull brakes with brake levers with a short cable travel.

Hydraulic rim brake (strut assembly)

Hydraulic rim brakes for mounting on the struts or fork bars are currently (2018) almost exclusively manufactured by Magura . In all models, two opposing brake cylinders press the brake shoes directly onto the rim flanks. In contrast to most hydraulic disc brakes, there is no automatic pad adjustment or the necessary expansion tank. The lining wear must be compensated manually by means of an adjusting screw on the brake lever that reaches into the hydraulic fluid. With brakes from Magura, factory-specific brake pads are required that can be replaced without tools.

The brake cylinder is attached to the cantilever base using a bracket-shaped mounting plate, comparable to the brake booster. To remove the wheel or the brake lining, a brake cylinder can be removed by opening a clamping lever. There are also designs for direct mounting that do not require a mounting plate. Here the brake cylinder is attached directly to the struts or fork bars using two threaded bushings or special mounting adapters. (For hydraulic fluid and brake line, see chapter on control )

Coaster brake

Freewheel hub with coaster brake
like the Komet hub
(cut open)

Hub gear with coaster brake

The coaster brake is a brake in the rear hub of the bicycle . It is operated by stepping back on the pedals.

In Germany, the coaster brake on everyday bikes was the standard brake on the rear wheel for a long time. For a hub brake, a non-positive connection to the crank via the chain is required when pedaling backwards; this is not the case with a chain shift . With the increasing spread of derailleur gears, the market share of the resignation decreased. So far, the coaster brake still has a certain importance in city bikes with hub gears and children's bikes without gears, as well as additional third brake when e-bikes with hub gears and V-brake at the rear and front wheel.

Use in the city is advantageous, as adequate braking is usually possible even when giving hand signals with just one hand on the handlebars. The coaster brake is conditionally suitable for use with long descents and high total weight, see section #Stability . When used in everyday life, the coaster brake is robust, very durable and virtually maintenance-free. There is no need to adjust or replace the brake pads, and there are no brake levers and controls. Wet conditions have no effect on the braking effect. (At most in extreme off-road use, larger amounts of water or penetrating mud could impair the mechanism.) If the chain jumps off the pinion or chainring or if the chain breaks, the coaster brake becomes inoperable. The braking action of the coaster brake is partly dependent on the pedal position and varied in the historic hub gears to some extent with the gear selection.

With internal hub brakes, the pedal movement leads via various mechanisms to the fact that cylindrically shaped jaws are placed on the inside of the housing of the rear wheel hub. Almost always a split steel sleeve is spread apart, which is slit in length or consists of several shells, and thus presses against the likewise metal inner wall of the hub housing. The functional principle is similar to the drum brake , but the brake shoes are usually narrower and longer and have a special, dry-running brake lining.

The fixed inner expansion sleeve is also referred to as the brake jacket . It is connected to the bicycle frame via the axle. So that the expansion sleeve and axle do not turn with the hub shell and wheel when braking, they are connected to a frame strut via an external lever arm. This lever arm is also referred to as a torque arm . The expansion sleeve, like all other moving parts of the hub, is surrounded by a temperature-resistant grease jacket.

Regreasing is usually not necessary with modern designs and can only be done by disassembling the hub. If the grease has run out due to overheating of the hub, a (viscous) oil can be added to the side of the hollow axle of the hub when the wheel is on its side. In contrast to the original fat, the oil has to be refilled more often. Older versions up to around the 1980s were usually filled with lubricating oil ex works, which had to be topped up regularly via a nozzle ( helmet oiler ) in the hub housing.

history

Hubs with coaster brakes were produced in the USA by the companies New Departure and Corbin from 1898, in Germany by Fichtel & Sachs under the name Torpedo from 1903. Only a short time later there were also hub gears with integrated coaster brakes. With the hub gear with retraction, the foundation stone was laid for the company Fichtel & Sachs, which now produces components for the automotive industry. The bicycle technology division was sold to the SRAM company in 1997 . Although the "coaster brake" nowadays refers to a chain-operated internal hub brake, there were other versions at the beginning of development around 1900. For example, the English company BSA produced a coaster brake in which, when the bottom bracket shaft rotates backwards, brake pads are pressed onto the rim via a freewheel device and linkage. Coaster brakes are not permitted on racing bikes that are subject to the UCI regulations , as only brakes that can be operated using a hand lever are generally permitted.

variants

Roller principle: The brake jacket is spread apart by rollers. The rollers are held by the roller guide ring on a shaft with several ramp-like cams on the circumference. With less than an eighth of a turn of the shaft, the rollers are lifted by the cams and press the brake jacket above against the hub shell. The 4, 7 or 8-speed gear hubs from Shimano in the version with a coaster brake work according to the roller principle. See also: roller brake .

Cone principle: The brake jacket lies between two conical cones. The outer cone (lever cone) is connected to the torque support , the chain-side cone (brake cone) can be moved axially against the brake jacket so that it is spread between the two cones. There are differences in the type of freewheel and the drive of the brake cone.

The torpedo freewheel hub (1-speed) works with a roller freewheel (torpedo freewheel), the roller guide ring of which in the braking function pushes the brake cone axially towards the brake shell by means of ramp-like elevations on the face.

In the case of the Komet hub of the Frankfurt Stamp Works, manufactured by Fichtel and Sachs from 1929, a spindle nut is moved by means of a hollow threaded spindle (to which the pinion is attached), which is conically shaped as a cone on both end faces. When driving (pinion rotates forwards), the chain-side cone of the spindle nut creates a frictional connection to the inner cone of the hub housing, which is released again during freewheeling (hub housing rotates faster than the pinion), as the threads pull the spindle nut out of the inner cone of the hub. When braking (pinion rotates backwards), the cone on the other side of the spindle nut spreads the brake jacket or, on some models, presses the discs of a multi- disc brake together .

Further examples of backstep hubs based on the cone principle are the Centrix hub, which was developed by R. Gottschalk , or the Favorit hub, a replica of the torpedo freewheel hub. The withdrawal from many previously manufactured hub gears, such as the torpedo 3-speed hub , also works in this way.

Roller brake

The roller brake is a variant of the coaster brake based on the roller principle, except that it is not actuated via the coaster but by means of a conventional brake lever and cable.

Roller brakes are only manufactured by Shimano as an add-on brake (Inter-M-Brake). By means of a toothing, they can be mounted on the hub body of specially suitable front wheel hubs and gear hubs. As with the coaster brake, all inner parts of the roller brake are surrounded by a grease coating. There is an opening in the housing for relubrication with the special brake grease.

Like the coaster brake, roller brakes without a heat sink are usually only suitable for areas of application that do not require excessive braking power and the braking duration is not too long, such as on long downhill stretches. For cargo bikes, touring bikes and tandems, models are offered with a cooling disk rotating with the hub body, which should be durable.

drum brake

An open drum brake, the brake shoes have been removed

On bicycles, the drum brake is used as a simplex brake with a lever-operated expansion cam, as can also be found on simple motorcycles or mopeds with cable brakes. Only a few manufacturers still produce drum brakes for bicycles, for example Sturmey-Archer , which has had them in their range since 1930. The drum diameter is between 70 mm and 90 mm. Drum brakes are also available in combination with gear hubs or dynamo hubs . While the similarly acting roller brake can be completely removed from the hub, the brake drum is part of the hub housing in today's models. In contrast to roller brakes, the braking surfaces must remain free of grease. The lack of a fat layer makes it easier for water to penetrate.

A special version was the Böni drum brake on earlier Swiss military bikes . From 1944 onwards, this was an add-on drum brake to the torpedo coaster hub from Fichtel & Sachs as an additional brake operated by a cable.

Band brake

Band brake for the rear wheel

Simple band brakes are used almost exclusively on traditional bicycles and cargo tricycles of Chinese production as rear brakes, the brake lever is often mounted on the frame as a handbrake.

In the better form with a metal band and handbrake lever, they can be found on a few types of bicycles from the 1970s and 1980s. They are still used on children's bicycles and children's balance bikes .

The eponymous tape runs loosely around a brake drum, the actual brake lining is on the inside of the tape. For braking, the tension of the belt is increased and the diameter is reduced. Continuous braking, as with many bicycle brakes, does not make sense or leads to excessive heating of the brake drum and belt.

Disc brake

Hydraulic 4-piston brake with floating brake disc - Postmount attachment without adapter

Mechanically operated disc brake - IS2000 mount

Although the disc brake is one of the more recent developments in bicycle technology, the American patent US526317 dealt with a mechanical disc brake for the rear wheel of a bicycle as early as 1894. In Neurädern in the area Mountain , Gravel bike and cyclocross disc brakes are now standard. In the early 1970s, the bicycle manufacturers Schwinn (USA) and Bridgestone (Japan) produced bicycles with disc brakes on the rear wheel. Shimano released the mechanical disc brake B700 in 1972 and the hydraulic model B900 in 1973 . The component manufacturer Phil Wood (USA) had a disc brake in its range during the same period. For a long time, disc brakes on bicycles remained a pure niche product. It was not until the mid-1990s that this construction became popular, especially for mountain bikes, and achieved the market breakthrough. According to the World Cycling Association UCI , it has been allowed in cyclocross races since the 2010/11 season .

Types of execution and design features

Hydraulically operated disc brake: By far the predominant type (as of 2018) is the fixed calliper brake with one piston on each side. Four- and six-piston brakes are also available for more heavily stressed brakes. Almost all models have an automatic pad adjustment, which ensures that the slave piston in the brake calliper is always the same distance from the brake disc after the brake is released. An expansion tank on the master piston of the brake lever ensures that the brake fluid is replenished when the slave piston gradually pushes out of the brake caliper due to the wear of the brake lining. In contrast to the car, the expansion tank is usually sealed off from the outside air by a membrane so that no liquid escapes from the ventilation holes when the bike is lying down or turning around. Floating caliper brakes are hardly produced. The only known floating caliper brake was the Gustav M model by Magura, which was produced for over a decade from 1997. (For hydraulic fluid and brake line, see chapter on control ); A special version is the hydraulic disc brake from BFO (as of 2018). In the hydraulic circuit of a closed system (without expansion tank) there is a stepped piston built into the brake caliper between the master and slave pistons, the larger piston surface of which faces the master piston. When the brake is released, the stepped piston has no function because an open valve guides the hydraulic fluid through the piston. When braking, this valve closes when the pressure point is reached (lining touches disc) due to the pressure increase. As a result, the hydraulic circuit is separated into two separate circuits and the hydraulic transmission ratio is increased in accordance with the ratio of the piston surfaces of the stepped piston. Practice has shown that water can be used as the brake fluid in this design.
Mechanically operated disc brake: Some disc brakes are controlled by a cable. There are versions for brake levers with a long rope length (for V-brakes) and a short rope length (for all other brakes). In the case of simple, mechanically operated disc brakes, the pads sit in a fixed caliper and can only be moved linearly on one side; when braking, the disc is pressed by the movable lining onto the stationary lining. More complex mechanical disc brakes have pads that can be moved linearly on both sides, comparable to hydraulic fixed calliper brakes.
Mechanically operated hydraulic disc brake: One possible design corresponds to the hydraulic fixed calliper brake, but with the master piston and expansion tank also located in the brake calliper. The master piston is operated using a conventional mechanical brake lever with a Bowden cable. Alternatively, the master piston and expansion tank can be housed in a separate housing called a "converter". Compatible hydraulic brake calipers can be connected to the converter.

Brake disc

The common diameters are 140, 160, 180, 200 and 203 mm. Occasionally these sizes are denoted by numbers between 5 and 8, the nominal (rounded) diameter in inches. For racing bikes, gravel bikes and cyclocross bikes, 140 and 160 mm are common. Larger diameters are used on some trekking bikes, mountain bikes and cargo bikes. In downhill sports, as well as touring bikes and tandems, brake discs with a diameter of at least 180 mm should be installed. Intermediate sizes are possible because the position of the brake caliper can be adjusted with adapters.

The larger the diameter of the brake disc, the higher the deceleration that can be achieved with the same manual force as well as the continuous braking power that can be achieved. On almost all types of bicycle, the front wheel can be braked more than the rear wheel without locking. A larger brake disc is often used there than on the rear wheel.

The fastening of the brake disc to the hub is based on the Centerlock and IS2000 standards . Centerlock is a system from Shimano in which the disc is pushed onto a multi-tooth profile on the right edge of the hubs and fixed with a locking ring. For this purpose, the same tool is used that is used to screw the locking ring of the gear rim packs . With IS2000, the brake disc is attached to the hub with six screws. Adapters are available to attach IS2000 discs to Centerlock hubs. The Rohloff gear hub has a special mount with 4 screws.

The friction surface of almost all brake discs is made of steel. In order to reduce the weight, brake discs with aluminum or titanium friction surfaces have also been developed, but these wear out faster. Brake disks consisting of an aluminum carrier disk on which the concentric, thin friction surfaces made of steel are plated on both sides are also widespread . Often there is a protrusion of the carrier aluminum beyond the friction surface towards the hub in order to increase the thermal capacity of the disc and the cooling surface.

Brake discs consisting of a separately riveted friction ring on an aluminum spider are possible. In order to minimize the distortion due to thermal expansion , the friction ring can also be fastened in such a way that it can expand freely radially outwards. This type is known as a "floating disc", which is also available with an increased thickness of around 3 mm as an internally ventilated brake disc (as of 2018 - only with a diameter of 203 mm).

Otherwise, brake discs have a thickness of 1.8 mm to 2.0 mm.

Brake pad

Brake linings consist of a carrier plate to which a friction lining is applied, which can consist of sintered metal (sintered lining) or a plastic resin with embedded friction materials (organic lining). The shape and mounting of the brake pad are not standardized, but rather manufacturer or model-specific.

With new brake pads, the full braking effect is only achieved after a certain running-in period. In the rest position, the brake pads are only a few tenths of a millimeter away from the disc. The thinner the disc and the larger its diameter, the easier it is for it to warp due to overheating or the use of force and to rub against the pads.

Magura prescribes that brake pads are replaced if the pad, including the carrier plate, is less than 2.5 mm thick. Shimano requests a pad change if the pad is less than 0.9 mm thick without a carrier plate.

Attachment of the brake caliper

There were various designs for attaching the brake caliper to the fork and frame (e.g. IS1999), which were reduced to the IS2000 and Postmount standards from 2000 . These two standards are compatible with each other by means of an adapter. The postmount standard is predominant in 2017. In 2015, Shimano introduced the open standard flat mount especially for racing bikes .

Postmount
Also known as PM , in the past sometimes also called Manitou Standard , as this type of attachment was first seen on Manitou's suspension forks. On the strut or the fork blade there are two post-like bases, each of which has an M6 threaded hole at a distance of 74.2 mm from each other. The aligned end faces of these bases are parallel to the impeller axis. The vertical distance between the face plane and the lower base axis to the wheel axis depends on the diameter of the brake disc. The most common is the version for a disc diameter of 160 mm. If the PM socket size and the diameter of the brake disc match, a PM brake caliper can be attached directly to the socket. An adapter is required for larger brake discs, smaller ones are not possible.
IS2000
Also known as the International Standard or IS . IS brake calipers are hardly on the market anymore (as of 2017). The IS mount is still carried out on the rear dropout, especially with the adjustable dropout. An IS mount is still common for rigid steel forks. In the plate-like IS mount, there are two bores at a distance of 51 mm parallel to the impeller axis. The IS mount is usually designed for brake discs with a diameter of 160 mm on the front wheel and 140 mm on the rear wheel. An IS brake calliper can then be attached directly with an M6 screw connection. Adapters are required for larger brake discs. Nowadays (2017) a PM brake caliper is usually installed in an IS mount using an adapter.
Flat Mount
This standard is only intended for disc diameters 140 and 160 mm. The area of application is the racing bike. There are two vertical through-holes on the chain stay, so that the flat-mount brake caliper for size 140 on the chain stay can be screwed on directly from below. An adapter plate is also required for size 160. Both sizes are attached to the fork using an adapter plate on a base, comparable to the postmount standard, except that the center distance is 70 mm and the internal thread is M5. Postmount brake calipers can also be used on the front and rear wheels with an adapter.

The braking force torque is introduced asymmetrically into the frame or fork via the brake caliper mount only on one side of the frame. With the fork in particular, the different loads on the fork legs mean that the fork can twist in itself. In general, the fork leg on which the brake caliper sits is subjected to a significantly higher load than with the rim brake. Forks for the use of a disc brake must therefore be made stronger. One way to increase the torsional stiffness of the fork is to use thru axles .

Mounting positions of the brake caliper for the rear brake

Installation positions on the rear wheel:
red = behind the seat stay, green = on the chain stay

behind the seat stay

on the chainstay

Typically, the rear brake caliper is attached behind the seat stay on a conventional diamond frame . This position makes it possible to keep the traditional cable routing over the top tube.

Alternatively, there is the option of attaching the brake caliper to the chain stay (referred to as low mount in Anglo-Saxon usage ). This installation position is particularly advantageous for everyday bicycles, as special solutions for a luggage rack are unnecessary.

Recuperation brake

The recuperation brake is a type of brake for electric bicycles . Here the motor acts as a generator and converts the kinetic energy into electrical energy. It is then used to charge the battery. Advantages are the maintenance-free and weather independence. Recuperation brakes have a limited braking power due to the components (generator, electronics, battery). When the battery is fully charged and without additional energy dissipators such as braking resistors , they are also ineffective because no more energy can be absorbed. This situation can occur when driving downhill. This type of brake is therefore only an additional brake, and an additional brake system is necessary on the bicycle, because Section 65 (1) sentence 2 StVZO requires two independent brakes for bicycles. In addition, the braking power is heavily dependent on the wheel speed and the motor / generator is thermally loaded. A high harvest factor is given in mountainous terrain. There, however, the engine is already heated from the previous uphill drive.

Recuperation brakes are offered, for example, by hub motors from Alber, BionX , GoSwiss, Klever and Panasonic.

Operation and control

Only the coaster brake is released via the pedals. Almost all other types of bicycle brakes are operated via a handbrake lever attached to the handlebar .

Before the Bowden cable was introduced around 1900, brakes were controlled via a linkage. The linkage brake was widespread in utility bikes until the 1950s and can still be found today on bikes made in India or China. Usually a rocker-like lever is rotatably mounted below the handlebar and when actuated presses a block brake onto the front wheel via a vertical rod . Later, rim or hub brakes on the front and rear wheels were also operated via tie rods. The cranked brake lever then often steers a pull rod via a short arm.

The fastening screws of modern handbrake levers should only be tightened so tightly that the levers do not change their position during normal use of the bicycle. If the bike falls, the lever can give way and move. This makes it unlikely that the lever will break off when subjected to force. The position of the lever can also be easily adapted to the driver's wishes. In general, the levers on the handlebars are oriented at an angle of about 45 to the horizontal.

In the case of fast descents on uneven slopes, the brake levers are often only rotated slightly forwards from the vertical, so that fingers and hands can grip the handlebars as far as possible when braking. As a rule, the brake levers should point as an extension of the forearm or be even lower. If it is then difficult to reach the handle, it is possible on many models to position the lever closer to the handlebar grip. In general, a screw must be screwed in on the opposite side of the fixed part of the brake lever. Ideally, it should be possible to operate the brakes with just the middle finger on fast off-road descents so that the other fingers can safely grip the handlebars.

Mechanical actuation

The actuation of the brakes by hand brake levers attached to the handlebars with power transmission via a Bowden cable is widespread. The Bowden cable consists of a pressure-resistant outer casing in which a thin steel cable runs, which is also called a brake cable , cable or inner cable .

Brake lever with adjustable lever arm. For use with the V-brake, the suspension point of the steel cable is set by turning the red knurled wheel outwards. For use with cantilever and conventional rim brakes, it is placed inwards.

Handbrake levers are offered in two versions, which differ in the length of the cable-hauling path . With classic handbrake levers, the suspension point of the brake cable is closer to the pivot point of the brake lever. This results in a short rope haul distance with high rope pulling force. They are used with side-pull brakes, center-pull brakes, cantilever brakes, mini-V-brakes, U-brakes, drum brakes and roller brakes. Brake levers with a long cable haul distance were introduced with the newly developed V-brake, as this has longer brake arms with greater leverage. Mechanically operated disc brakes are available for both brake levers with long and short cable lifts. Special brake levers allow the rope length to be adjusted by changing the lever arm between the joint and the attachment point of the brake cable nipple.

One end of the brake cable usually ends with a pressed-on barrel nipple that is hooked into the corresponding receptacle on the brake lever . Some traditional racing bike brakes have a socket for pear nipples instead. The other, freely terminating end of the inner cable is usually attached to the actuating element of the brake itself by means of a clamping screw. The outer shell is supported on the frame (e.g. with cantilever, center pull and U-brakes), a separate counter bearing (e.g. with drum, roller and mechanical disc brakes) or on the opposite lever of the brake body (V - and side-pull brake).

Before pulling in the inner cable, a metallic sleeve ( end cap ) is usually pushed over both ends of the cut-to-length sheath of the Bowden cable in order to achieve a reliable fit of the sheath in the receptacle and to protect it against kinking and compression. With older brake levers, another sleeve with a slightly larger diameter was pushed over the end sleeve, via which the sleeve was supported on the base body of the brake lever. Modern standard handlebar brake levers usually have longitudinally slotted adjusting screws which take up the cover (with or, depending on the version, without end cap) after the brake cable has been attached. The longitudinal slot allows the cable to be unhooked from the handbrake lever without having to loosen the inner cable on the brake. In the past, the adjustment screws were mostly on the brake itself.

The outer diameter of the casing is usually 5 mm. The pull rope has a diameter of 1.6 mm, less often 1.5 mm. A spiral cover is predominantly used, less often a limb- like cover . Compression-free covers , such as those used for shift cables, should not be used for brake cables, since their parallel strands can be driven apart by the brake cable when high tensile forces occur, whereupon the brake becomes ineffective.

The middle part of the brake cable leading to the rear brake often runs freely along the top tube. Only the beginning and end of the cable run then between the handlebar or brake and the counter bracket connected to the frame through a cover. The cover leading to the brake can be omitted if the deflection is done via a roller or guide attached to the frame. The shorter the sleeves used, the more direct the power transmission to the brake, as the compression of the outer sleeve and the frictional resistance of the inner cable are reduced.

Hydraulic actuation

Hydraulic brakes are operated via a brake line filled with brake fluid or hydraulic oil.

Hydraulic brake lines consist of a flexible, pressure-resistant hose that is pressed with manufacturer-specific connectors. In contrast to brake cables, hydraulic brake lines have virtually no frictional resistance, corrosion, contamination and wear.

Hydraulic fluid

In contrast to models filled with mineral oil , brakes that are filled with brake fluid in accordance with the DOT specification have to be serviced regularly, since brake fluid is hygroscopic , i.e. it absorbs water. Exchanging the brake lines, refilling and bleeding requires special tools. Without proper ventilation, air can collect in the expansion tank, which is sealed off from the outside air by a membrane. When turning the wheel, the air can get into the hydraulic circuit when the brake lever is operated.

Most manufacturers use a brake fluid according to DOT standards 3, 4 or 5.1 as the hydraulic fluid . DOT 5 silicone-based brake fluid is not used in bicycles and cannot be mixed with the other DOT glycol-based fluids. Miscibility with water is mentioned as an advantage of DOT brake fluids. Water that gets into the brake circuit due to a handling error is absorbed by the brake fluid and distributed in the system. The influence on the boiling temperature of the liquid is therefore manageable and depends on the amount of water. Since small amounts of water also get into the brake fluid through hoses and connection points, it is usually provided in motor vehicles that a complete replacement be carried out every two years. DOT brake fluid can be obtained cheaply. However, it should not be bought in advance, as opened packaging cannot be stored for a long time without the brake fluid absorbing water.

The manufacturers Magura and Shimano in particular use mineral oil as hydraulic fluid. As soon as a small amount of water gets into a system filled with mineral oil, it will settle in the brake cylinder as the lowest point of the system and cause the boiling temperature to drop from well over 200 ° C to 100 ° C. The low maintenance requirement is seen as an advantage of mineral oil. Mineral oil does not age, it does not have to be replaced, seals and hydraulic pistons do not stick and generally do not need to be cleaned, as is the case with DOT brake fluids occasionally after a few years.

Hydraulic hoses

Hydraulic hoses with an outer diameter of 5 mm are usually used on bicycles, steel braided and other special lines also with an outer diameter of 5.5 mm.

Hydraulic hoses are either plugged directly into the brake lever and saddle and screwed, or an angled, hollow ring connector ( Banjo bolt or fitting ) is placed in between, which leads the hose to the side. The ring is sealed on both sides with O-rings and fastened with another banjo screw. Special connection fittings are designed to be rotatable in order to avoid twisting in the hydraulic line.

High-quality Bowden pliers or a sharp, sturdy knife can be used to cut the hoses to length. The cut is to be made exactly at right angles.

Hydraulic hoses made of hard plastic are usually mounted with compression connection by first a threaded sleeve or an elongated nut (engl. Flare nut ), and then a crimping ring (often Olive called, engl. Olive fitting ) is pushed onto the hose. The end of the tube is then placed in a suitable recessed clamping block ( assembly block inserted) and clamped in the vice to a serrated hose nipple (also plug-in nipple or Einschlagpin called, engl. Barbed fitting ) to take, which serves as an internal supporting sleeve and a connector. The other end of the hose nipple is then pushed into the receptacle as far as it will go. The thread and olive are lightly greased and the threaded sleeve or union nut is carefully screwed over the connecting piece by hand in order to avoid tilting. The sleeve or nut is then tightened with an open ring spanner, because thin-walled sleeve nuts can be deformed by using a normal open-end wrench. The sleeve grips over the olive and squeezes it onto the tube. It is tightened until only one or two threads are visible. If necessary, the sleeve nut can then be unscrewed again in order to route and fasten the hose along the frame or fork.

Hydraulic hoses with an outer steel braid are also known as steel braided lines. The braid can be exposed or covered with a plastic layer. Instead of using a compression fitting, flexible steel and other special hydraulic lines are often sealed and fastened by screwing in a threaded nipple. This nipple usually has two or three threads with different diameters. The smallest thread is screwed into the hydraulic hose (for this, the hose may first have to be expanded and the neck of the thread greased). The adjacent thread is used to screw an elongated union nut (a threaded sleeve with an internal thread) that has been pushed onto the hose. Finally, the third thread is located at the other end of the nipple and is used for screwing onto the brake lever or brake caliper.

Handling and driving safety

Two brake systems that work independently of one another are essential, especially when driving down gradients. The otherwise very reliable coaster brake is also ineffective if the chain should jump off. Loaded (touring) tandems should even have three independent brakes to avoid overheating and overloading on long downhill journeys.

On a non-slip surface, most of the maximum possible braking force can be applied by the front wheel brake alone during emergency braking . The braking force is limited on firm ground by the fact that the driver would be lifted over the handlebars if the deceleration was too great. On soft or smooth surfaces, on the other hand, the braking distance can be almost halved by using the front and rear brakes.

Commercially available rim brakes often develop only a very low braking effect on steel rims when it is wet. On aluminum rims, on the other hand, they usually decelerate perfectly when they are wet as soon as they have dried off due to the frictional heat. Disc brakes brake well in wet conditions because they dry off very quickly.

For V-brakes and disc brakes with a high braking effect, the ability to control the braking power is important. Often these brakes can be used to brake the front wheel so hard that the driver falls over the handlebars because either the front wheel locks or the rear wheel lifts off. In particular, if the front wheel gets into a depression when braking, there is a risk of rollover.

A heavily braked rear wheel tends to slip , which can also cause the bike to break away from fast driving. This is because the rear wheel is relieved of pressure when braking hard ( dynamic axle load shift ) and thus locks easily. Shifting your weight backwards can help reduce braking distances and increase control of the bike. In any case, if the tire slips, the transferable braking force is reduced ( sliding friction is weaker than static friction ).

With tandems , recumbents with a long wheelbase , as well as touring and cargo bikes with additional load on the rear wheel, the relief of the rear wheel during braking plays only a minor role, so that the braking distance can be significantly shortened in these cases by using the rear brake.

The loss-free power transmission of hydraulic brakes offers advantages, especially on steep slopes and rough terrain, as the reduced braking force and poorer controllability due to the friction between the cable and the cover are noticeable here with mechanically operated brakes.

Manufacturer

Besides its own brands of distributors especially following manufacturers are original equipment manufacturers (English original equipment manufacturer , OEM ) and a retail presence.

The major component manufacturers SRAM ( Avid ), Shimano and Campagnolo . But also Dia-Compe , Tektro (premium brand: TRP), FSA, Lecchi, Promax, Alhonga, Saccon (Italy), Magura (primarily hydraulic brakes), Trickstuff (disc brakes, brake discs and brake pads), Alligator (brake cables and brake pads), SwissStop (Brake pads), Hayes (disc brakes), Cane Creek, Jagwire (brake cables and brake pads), Sturmey-Archer, and Sunrace (drum brakes) are examples from 2013.

Almost all European manufacturers have given up production or have been bought up. Formerly known brands were Weinmann , Altenburger , Mafac (France) and Zeus (Spain). Even if these manufacturers no longer exist, products are still sold under their names.

literature

Ulrich Artmann: specialist knowledge of bicycle technology . 6th edition, Verlag Europa Lehrmittel, Haan-Gruiten 2016, ISBN 978-3-8085-2298-1 .
Fritz Winkler, Siegfried Rauch: Bicycle technology repair, construction, production . 10th edition, BVA Bielefelder Verlagsanstalt, Bielefeld 1999, ISBN 3-87073-131-1 .

Web links

Commons : Bicycle Brakes - Collection of Images

Wiktionary: Fahrradbremse - explanation of meanings, word origins, synonyms, translations

Individual evidence

↑ The StVZO does not contain any further requirements on the type, quality or effectiveness of the brakes (see Section 65 StVZO)

↑ Implementing decision (EU) 2015/681 of the Commission of April 29, 2015 , accessed on February 15, 2019.

↑ In order to counteract the locking of the front wheel, a brake force limitation is provided for the front wheel of the Shimano roller brake, for example . Currently (2019) there are several manufacturers who are announcing an anti-lock braking system for bicycles.

^ IFA Touring. (No longer available online.) Archived from the original on September 3, 2014 ; accessed on September 24, 2016 .

↑ ddr-fahrradwiki.de

↑ Patent CH6896 : Système de frein pour perfectionné Velocipedes et autres véhicules à roues. Published January 13, 1893 , inventor: Robert-Steuart Erskine. ‌

↑ Raleigh spare parts list from 1977, model Tourist with stirrup brake (bracket brake or inner rim brake) . Accessed January 18, 2018.

↑ ^a ^b Cantilever Geometry , article in Wikipedalia.com

↑ patent DE1890527U : Improvements in or relating to rim brakes. Published on April 2, 1964 , inventor: Karl Altenburger. ‌

^ Synchronous brake from Altenburger - prospectus from 1961 , accessed on November 25, 2016

^ Sketch of how the "Delta Brake" from Campagnolo works , accessed on January 2, 2017

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↑ Shimano brochure from 1970, page 4: hydraulic rim brake, accessed on February 15, 2018

↑ mtb-news.de Photos of the Shimano Power Brake , accessed on February 15, 2018

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↑ Patent GB274755 : Improvements in brakes for bicycles and the like vehicles. Published July 28, 1927 , inventor: Marcel Jeay. ‌

↑ Patent US4765443 : Caliper brake for mountain bicycles having wide tires. Published 23 Aug 1988 , inventor: Charles Cunningham. ‌

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↑ Patent US4974704 : Self-energizing disc / rotor or rim brake. Published December 4, 1990 , Inventors: Steven Miller, F. David Pedersen. ‌

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^ Coaster brake from New Departure from 1898 , accessed on January 10, 2017

↑ Photo of a BSA coaster brake from 1902 (roughly in the middle of the page). Retrieved February 1, 2018

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↑ Gearboxes, clutches, drive elements , Springer Fachmedien, Wiesbaden 1957, ISBN 978-3-663-00586-5 , page 33: Torpedo freewheel. Retrieved February 1, 2018

↑ Handbook torpedo freewheel hub (1-speed) 1950s. Retrieved February 1, 2018

↑ History of the input coaster brake hubs built by F&S. Retrieved January 12, 2018

↑ Sectional drawing of the Komet hub (Komet Super). Retrieved February 1, 2018

↑ Gearboxes, clutches, drive elements , Springer Fachmedien, Wiesbaden 1957, ISBN 978-3-663-00586-5 , page 27, 28: Komet-Freilauf. Retrieved February 1, 2018

↑ Patent CH179635 : freewheel hub with coaster brake. Published September 15, 1935 , inventor: Richard Gottschalk. ‌

↑ Patent US526317 : Brake For Velocipedes. Published September 18, 1894 , inventors: JH Hendrick, AH Fay. ‌

↑ Shimano Catalog 1973 : Excerpt about disc brakes. Retrieved October 25, 2016.

↑ Trickstuff website - Know How - Automatic lining adjustment , accessed on January 5, 2018

↑ Bikeradar.com - Report from 2010 about the floating caliper brake "Gustav M" by Magura , accessed on January 5, 2018

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↑ Bikeradar.com - 2016 report on mechanical disc brakes , accessed January 5, 2018

↑ Instructions for replacing the brake pads , Trickstuff GmbH

↑ Disc brake service and repair - Shimano hydraulic brake service and adjustment , Section 3, ParkTool, Sept. 25, 2015

↑ Avid OEM Product Technical Specifications (Post Mount starting on page 6) - (PDF), accessed December 1, 2017.

↑ SRAM - Technical Manual 2003 (IS-2000 recording) - (PDF), accessed on December 1, 2017

↑ SRAM 2017 Road - Frame Fit Specifications (Flat Mount from page 73) - (PDF), accessed on December 1, 2017

↑ Heiner Schuchard: A tandem rigid fork for disc brakes. Published by Fahrradzukunft e. V., April 2010, accessed February 5, 2018

↑ Sevencycles.com, accessed on September 23, 2017

↑ E-bike motors, these are the most important manufacturers

^ Bike Repair Manual - Section " Shimano hydraulic disk brakes ", Chapter 37, page 412, Barnett Bicycle Institute

↑ A special, curved washer can be pushed over a pear nipple so that it fits into the receptacle intended for a barrel nipple.

↑ Ventilation instructions , In: Downhillschrott.com

↑ Alex Mansell: DOT Brake Fluid vs. Mineral Oil - and the Winner is .. , In: EpicBleedSolutions.com, accessed June 2018

↑ Overview of available 5.5 mm connection pieces from Alligator " 5.5 mm hydraulic hose fittings ", In: AlligatorCables.com

↑ Overview of available 5 mm connectors from Alligator " 5 mm hydraulic hose fitting installation options ", In: AlligatorCables.com

↑ ^a ^b Instructions for shortening the Trickstuff BETA Kevlar brake lines with Goodridge screw connection , February 2016, as well as assembly instructions for shortening Goodridge steel braided brake lines , October 2013, Trickstuff GmbH

↑ Syd Patricio: How To Change a Hydraulic Brake Line on Your MTB , December 18, 2014

^ Sheldon Brown and John Allan: Braking and Turning Your Bicycle ; older version in German: braking and turning

↑ sudibe.de: technik_bremsen

↑ Test: Trickstuff Doppelmoppel at cx-sport.de

[1] The StVZO does not contain any further requirements on the type, quality or effectiveness of the brakes (see Section 65 StVZO)

[2] Implementing decision (EU) 2015/681 of the Commission of April 29, 2015 , accessed on February 15, 2019.