 | This article needs to be updated. The reason given is: Most of this technology has moved on.(July 2021) |
A cyclocomputer, cycle computer, cycling computer or cyclometer is a device mounted on a bicycle that calculates and displays trip information, similar to the instruments in the dashboard of a car. The computer with display, or head unit, usually is attached to the handlebar for easy viewing. Some GPS watches can also be used as display.
In 1895, Curtis H. Veeder invented the Cyclometer. [1] [2] [3] The Cyclometer was a simple mechanical device that counted the number of rotations of a bicycle wheel. [4] [5] A cable transmitted the number of rotations of the wheel to an analog odometer visible to the rider, which converted the wheel rotations into the number of miles traveled according to a predetermined formula. After founding the Veeder Manufacturing Company, Veeder promoted the Cyclometer with the slogan, It's Nice to Know How Far You Go. [6] The Cyclometer's success led to many other competing types of mechanical computing devices. Eventually, cyclometers were developed that could measure speed as well as distance traveled.
A basic cyclocomputer with a wheel speed sensor may display the current speed, average speed, maximum speed, trip distance, trip time, total distance traveled, and the current time. More advanced models with additional sensors and storage may display and record altitude, incline (inclinometer), heart rate, power output (measured in watt) and temperature as well as offer additional functions such as pedaling cadence, a stopwatch and even GPS navigation and video data overlay synchronization. They have become useful accessories in bicycling as a sport and as a recreational activity.
The display is usually implemented with a liquid crystal display, and it may show one or more values at once. Many current models display one value, such as current speed, with large numbers, and another number that the user may select, such as time, distance, average speed, etc., with small numbers.
The head usually has one or more buttons that the user can push to switch the value(s) displayed, reset values such as time and trip distance, calibrate the unit, and on some units, turn on a back light for the display. Most displays are navigated by pressing buttons and high-end models use a capacitive touch screen to navigate screens and maps.
The older, traditional sensors have a magnet attached to a spoke of either the front or rear wheel. A sensor based either on the Hall effect, or on a magnetic reed switch, is attached to the fork or the rear of the frame. The sensor detects when the magnet passes once per rotation of the wheel and time stamps or time codes the revolution count. Alternatively, a sensor may be attached to the wheel hub. Distance is determined by counting the number of rotations, which translates into the number of wheel circumferences passed. Speed is calculated from distance against lapsed time period using the circumference of the wheel and the time it took to make one rotation.
To measure cadence (revolutions per minute of the crankarm), a magnet is mounted to the crankarm, and a sensor mounted to the frame. This works on the same principle as the speedometer function and measures the turning of the cranks and front chain ring.
Some models use a wired connection between the sensor and the head unit. Other models transmit the data wirelessly from the sensor/transmitter to the head unit. Data can be exported to a SD card, computer, or phone and uploaded to an internet web service. Wireless cadence and speed sensors use wireless communication standards ANT + and Bluetooth Low Energy and can directly communicate with a smartphone application that also uses the phone's GPS, barometer, temperature, clock, and other sensors to create a more detailed picture, record, or map.
Once a new computer is installed, it usually requires proper configuration. This normally includes selecting distance units (kilometers vs. miles) and the circumference of the wheel. Since the sensor measures wheel rotation, different wheel sizes will translate to different measures of speed and distance for a given number of rotations.
For more accuracy the bicycle (with the set cyclocomputer) must be ridden by the intended rider over an accurately measured distance. The computer's reading is then compared with the known distance and any necessary corrections made.
Besides variables calculated from the rotating wheels or crank, cyclocomputers can display other information.
For integrated shifters on racing bicycles, the gear can be read by the computer: Shimano's Flight Deck and Campagnolo's ErgoBrain work with their respective systems to detect the gearing. This allows indirect measurement of cadence. These systems do not have sensors on the crankset or cassette to determine what gear the bicycle is in. They work exclusively with the shifters, which may result in misleading information. Instead of knowing what gear the bicycle is in, they rely on sensing when the cyclist changes gears using sensors in the shifters. If the gear change doesn't actually happen, or the computer's sensors are too sensitive (e.g.: when braking with STI-style shifters), the information displayed is not accurate.
With additional sensors, other performance measurements are available:
Some models also have sensors built into the head that measure and display environmental parameters such as temperature and altitude.
Some more sophisticated models are able to measure the rider's power in terms of watts. These units incorporate elements that measure torque at the crank, or rear wheel hub, [7] or tension on the chain. [8] This technology began in the late 1980s. (See Team Strawberry for the early development and testing stages of this technology.)
Some cyclocomputers (such as the Garmin Edge, trimm One, Wahoo Elemnt Bolt or Hammerhead Karoo) can be loaded with maps and can thus show the rider's position on the map, or provide turn-by-turn directions for a pre-determined route.
Most electric bicycles have a microcontroller in the motor controller to calculate input cadence or torque, adjust amperage, control the motors and send the display screen information. Often cyclists can select the level of power assist provided using the computer. The computer also monitors the speed and can deactivate the motor for braking or if required by law (for example, in many countries pedelec bikes cannot use motor assist above 25 km/h).
A unicycle is a vehicle that touches the ground with only one wheel. The most common variation has a frame with a saddle, and has a pedal-driven direct-drive. A two speed hub is commercially available for faster unicycling. Unicycling is practiced professionally in circuses, by street performers, in festivals, and as a hobby. Unicycles have also been used to create new sports such as unicycle hockey. In recent years, unicycles have also been used in mountain unicycling, an activity similar to mountain biking or trials.
An odometer or odograph is an instrument used for measuring the distance traveled by a vehicle, such as a bicycle or car. The device may be electronic, mechanical, or a combination of the two (electromechanical). The noun derives from ancient Greek ὁδόμετρον, hodómetron, from ὁδός, hodós and μέτρον, métron ("measure"). Early forms of the odometer existed in the ancient Greco-Roman world as well as in ancient China. In countries using Imperial units or US customary units it is sometimes called a mileometer or milometer, the former name especially being prevalent in the United Kingdom and among members of the Commonwealth.
A tachometer is an instrument measuring the rotation speed of a shaft or disk, as in a motor or other machine. The device usually displays the revolutions per minute (RPM) on a calibrated analogue dial, but digital displays are increasingly common.
Campagnolo is an Italian manufacturer of high-end bicycle components with headquarters in Vicenza, Italy. The components are organised as groupsets (gruppi), and are a near-complete collection of a bicycle's mechanical parts. Campagnolo's flagship components are the Super Record, Record, and Chorus groupsets with all three representing their recent shift to 12-speed drivetrains. Super Record and Record are the top groupsets, followed by Chorus, Potenza, Centaur and Veloce. Campagnolo also produces aluminum and carbon wheels, as well as other components.
The crankset or chainset is the component of a bicycle drivetrain that converts the reciprocating motion of the rider's legs into rotational motion used to drive the chain or belt, which in turn drives the rear wheel. It consists of one or more sprockets, also called chainrings or chainwheels attached to the cranks, arms, or crankarms to which the pedals attach. It is connected to the rider by the pedals, to the bicycle frame by the bottom bracket, and to the rear sprocket, cassette or freewheel via the chain.
A speedometer or speed meter is a gauge that measures and displays the instantaneous speed of a vehicle. Now universally fitted to motor vehicles, they started to be available as options in the early 20th century, and as standard equipment from about 1910 onwards. Other vehicles may use devices analogous to the speedometer with different means of sensing speed, eg. boats use a pit log, while aircraft use an airspeed indicator.
A brushless DC electric motor (BLDC), also known as an electronically commutated motor, is a synchronous motor using a direct current (DC) electric power supply. It uses an electronic controller to switch DC currents to the motor windings producing magnetic fields that effectively rotate in space and which the permanent magnet rotor follows. The controller adjusts the phase and amplitude of the current pulses that control the speed and torque of the motor. It is an improvement on the mechanical commutator (brushes) used in many conventional electric motors.
A dynamometer or "dyno" for short, is a device for simultaneously measuring the torque and rotational speed (RPM) of an engine, motor or other rotating prime mover so that its instantaneous power may be calculated, and usually displayed by the dynamometer itself as kW or bhp.
A fixed-gear bicycle is a bicycle that has a drivetrain with no freewheel mechanism such that the pedals always will spin together with the rear wheel. The freewheel was developed early in the history of bicycle design but the fixed-gear bicycle remained the standard track racing design. More recently the "fixie" has become a popular alternative among mainly urban cyclists, offering the advantage of simplicity compared with the standard multi-geared bicycle.
Gear ratios of bicycles are relative measures of bicycle gearing giving an indication of the mechanical advantage of different gears, which combined with the wheel diameter determines how far the bicycle advances per pedal or crank revolution.
An electronic speed control (ESC) is an electronic circuit that controls and regulates the speed of an electric motor. It may also provide reversing of the motor and dynamic braking. Miniature electronic speed controls are used in electrically powered radio controlled models. Full-size electric vehicles also have systems to control the speed of their drive motors.
In cycling, cadence is a measure of rotational speed of the crank, expressed in units of revolutions per minute. In other words, it is the pedalling rate at which a cyclist is turning the pedals. Cadence is directly proportional to wheel speed, but is a distinct measurement and changes with gearing. In other words, the gearing changes the ratio of the crank's rotational speed (cadence) to that of the drive wheel's rotational speed.
Bicycle gearing is the aspect of a bicycle drivetrain that determines the relation between the cadence, the rate at which the rider pedals, and the rate at which the drive wheel turns.
A cycling power meter is a device on a bicycle that measures the power output of the rider. Most cycling power meters use strain gauges to measure torque applied, and when combined with angular velocity, calculate power.
Bicycle performance is measurable performance such as energy efficiency that affect how effective a bicycle is. Bicycles are extraordinarily efficient machines; in terms of the amount of energy a person must expend to travel a given distance, cycling is calculated to be the most efficient self-powered means of transportation.
A Pedelec or EPAC, is a type of low-powered electric bicycle where the rider's pedalling is assisted by a small electric motor. However, unlike some other types of e-bikes, pedelecs are classified as conventional bicycles in many countries by road authorities rather than as a type of electric moped. Pedelecs have an electronic controller that cuts power to the motor when the rider is not pedalling or when a certain speed – usually 25 km/h (16 mph) or 32 km/h (20 mph) – is reached. Pedelecs are useful for people who ride in hilly areas or in strong headwinds. While a pedelec can be any type of bicycle, a pedelec city bike is very common. A conventional bicycle can be converted to a pedelec with the addition of the necessary parts, e.g., motor, battery, etc.
A variable reluctance sensor is a transducer that measures changes in magnetic reluctance. When combined with basic electronic circuitry, the sensor detects the change in presence or proximity of ferrous objects.
The Jones Counter is a type of bicycle odometer which adds the function of a surveyor's wheel to a bicycle. It was developed in 1971 by Alan Jones to accurately measure the length of road running race courses. The counter has gears that drive a mechanical digital counter. One count typically corresponds to about 1/20 of a wheel revolution ; this provides a resolution of about 10 cm in course length, although overall accuracy, depending on calibration and other factors, is lower, but normally better than 1 part in 1,000.
A crank sensor (CKP) is an electronic device used in an internal combustion engine, both petrol and diesel, to monitor the position or rotational speed of the crankshaft. This information is used by engine management systems to control the fuel injection or the ignition system timing and other engine parameters. Before electronic crank sensors were available, the distributor would have to be manually adjusted to a timing mark on petrol engines.
Bicycle drivetrain systems are used to transmit power on bicycles, tricycles, quadracycles, unicycles, or other human-powered vehicles from the riders to the drive wheels. Most also include some type of a mechanism to convert speed and torque via gear ratios.
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