What does bike computer show

Range of possibilities of bike computer is large. Depending on user's needs, pricing policy and functionality, devices can be conditionally divided into basic and advanced.

Entry-level models display minimum required set of information:

Advanced cycling computers are indispensable companions for professional athletes, as well as cyclists who want to increase trip comfort and safety. They support synchronization with various sensors and can show lot of useful data:

Practical application of data is solely determined by user. Some need them for training, others for weight loss, others for bike care and timely maintenance.

Bicycle speedometers

Types of bike computers

It's time to figure out what bike computers are? Their classification is based on connection type. They can be wired or wireless. It should be noted right away that difference in price can be enormous. If wired type costs an average of $30, then for wireless one you will have to pay about $300. It all depends on destination. For most riders, basic functionality will suffice, while advanced features will come in handy for pros.

Main advantages of wired type include:

  • Affordable price
  • No battery in sensor
  • High accuracy
  • Interference immunity

Disadvantage is possibility of damage to connecting cable and inability to connect additional sensors.

Advantages of wireless bike computers include:

Of course, main disadvantage is price, and possibility of interference can be attributed to secondary ones, although there are usually no problems when connecting via Bluetooth.

Wired cike computers

Bike computer operation principle

Structurally, any bicycle computer consists of three main parts: base (computer itself, digital unit on handlebar), sensor and magnet. Regardless of type, principle of operation is the same. Only difference is in the way information is transmitted from sensor to base (via air or wire).

Digital block is mounted on handlebar and is synchronized with sensor, which is usually represented by reed switch - an electromechanical switching device. That is why one of the components is magnet, since it is able to activate the reed switch. Sensor is attached to the fork leg, and magnet is attached to the spokes. With each revolution of wheel, their short-term interaction occurs, which leads to closure and opening of contacts.

Bicycle computer reed switch operation principle .

Understanding principle of operation allows us to answer question, how does bike computer calculate distance and speed? Computer reads each revolution of wheel using sensor, gives speed and distance readings based on two parameters - diameter of wheel (entered by user during initial setup) and time spent on one revolution. Of course, there is always room for error, as bicycle tires can have different thicknesses and additional off-road tread.

How does bike computer calculate cadence? By the same principle, using sensor on frame and magnet on crank. By making full rotation of pedals, magnet passes through sensor, and computer processes each actuation and calculates cadence. Despite complexity of wording, everything is quite simple.

Cadence sensor wiring diagram.

To read heart rate, special wireless wearable cardio sensor is provided (usually purchased separately), for example, Sigma R1 Duo Comfortex + or Polar H10. It should be noted that modern sensors are autonomous and are able to connect to compatible devices (smartphone, tablet, sports and medical equipment) using ANT + technology.

Wireless Bike Computers

How to install bike computer sensor correctly

If you want to receive adequate data without errors, ensure integrity of components and even prevent wheel breakage, you need to understand how to properly install bike computer sensor. Process will not cause any particular difficulties, but there are several points that should be taken into account in order to do everything right. Let's look at complete procedure, and for better visual perception, pay attention to photo.

Installation of bicycle computer sensor.
  • Computer mount installation. Manufacturers rarely use special collar, opting for nylon ties. This allows you to independently determine best installation location, without being tied to any parameters. Most practical and popular are stem or handlebar itself. We thread the ties into the grooves and tighten securely. Cut off the excess with pliers or scissors.
  • In case of wired connection, cable must be properly secured. It is best to wrap it around brake cable housing, and then along the fork itself. When turning handlebar and activating the brake, there should not be any tension that could lead to break in connection. If sensor is wireless, then move on.
  • Next step is to correctly install bike computer sensor on fork leg. It is pre-fixed, this is also done with ties, but do not immediately tighten them tightly, as subsequent adjustment of location will be necessary. We need inside of fork to provide minimum clearance. It is also recommended to move the sensor forward slightly. This will avoid breakage in case of foreign objects (sticks, grass, dirt) getting into wheel and scrolling. So sensor will simply move in direction of wheel, and will not break, which will lead to its breakage and deformation of wheel spokes.
  • Now you need to fix magnet 1 - 2 cm above crosshairs of spokes and adjust distance between it and reed switch. Main rule is that they must be at the same level (height). When turning the wheel, the magnet must pass through the place indicated on sensor. Usually, manufacturer determines required clearance in instructions for bike computer. Smaller it is, more efficient. It all depends on quality of reed switch itself and power of magnet used, which cannot be visually determined. Optimal gap is 3 - 5 mm, and maximum - 3 - 12 mm. If wheel is with small "eight", then be sure to take this fact into account when setting it up. In this case, it is better to install magnet at the point of closest contact. We placed everything correctly, now you can firmly fix ties - sensor is installed.
Smartphone connected cycling computers

List of abbreviations used during setup

Setting up the bike computer settings can be difficult for beginner. Problem lies in incomprehensible characters and abbreviations that appear on display. Unfortunately, it is not possible to show the full names of functions and settings due to the compactness of device and, accordingly, screen. All current information is also displayed in abbreviated form. Therefore, our experts decided to share list of basic abbreviations that are used in bike computers. Table is advisory in nature, as manufacturers may use different abbreviations.

Table of abbreviations used in cycle computers
Decryption Decryption
SPD Current speed
AVS or AV SPEED Average speed
MAX or MXSPD Max speed
RT or TM Ride time
TRT Total ride time
DST Total distance (for this trip)
TOT DST or ODO Total mileage (all time)
Mph or Kmh Speed unit m (miles)/h or km (kilometers)/h
WS Wheel size
CLK or TIME Clock
CAL Calories burned
FAT Fats burned
TEMP or TEP Temperature

Any product is completed with instructions for installation and configuration, where manufacturer describes in detail all abbreviations.

How does GPS bike computer work?

Bicycle computers with a GPS module are considered most advanced and provide additional features that are not inherent in classic models. The main advantage is the function of building and tracking the route. It can be implemented both on the screen of the computer itself, and via smartphone connected via Bluetooth. GPS system works here in the same way as in other navigation devices - navigators, on-board computers. Bike computer is able to interact with satellites (usually at least 4 of them) in order to more accurately determine the current position and speed of movement in real time. In practice, we get rid of sensor on the plug and problems associated with its connection and interaction. Everything you need is in one computer unit on handlebar. Most GPS bike computers have touch screen for easy control while riding. In addition to maps and navigation, GPS module provides an alarm mode. If bike starts moving or leaves the built route, user will receive notification on smartphone.

Possible causes of failures

During the operation of bicycle computer, malfunctions may occur. Most often, users are interested in why bike computer does not show speed? Based on above, number of reasons can be identified:

  • Gap between reed switch and magnet is incorrectly set. Often there is just shift in the process of active skiing, especially over rough terrain. Both the magnet and sensor can change location
  • Influence of wheel rim deformation ("eight")
  • Cable break (for wired type)
  • Base and transducer synchronization failure (for wireless type)
  • Dead battery in computer or wireless sensor
  • Damaged reed switch or control board in the base
  • Poor contact of base with the mount (for wired type)

If bike computer displays basic information (time of day, total time and distance), it is possible to switch modes and control functions, but the readings of the current race do not change, then the reasons are similar to those listed above.

Sometimes the bike computer does not turn on at all. The most common cause is a dead battery. If the replacement does not help, then the problem is most likely in the control board. If such situation is observed in winter at negative temperatures, then it is necessary to test performance in normal climatic conditions. In cold, batteries can lose up to 70% of their energy supply, so it will not be enough to operate device.

If bike computer has not been used for several years and has stopped displaying information, then battery is first likely cause, which usually lasts 2 to 3 months. If data is visible on screen, but cycle computer does not perform its functions while riding, then it is also worth paying attention to probable causes of the failure indicated above for speed display problems.

For wired models, weak point is pad, i.e. junction of the stand and bike computer itself. If ride is carried out off-road, then vibration may cause play between plastic parts, contact may be broken.

It is worth noting that most of the problems are related precisely to sensor and its setting relative to magnet (position, gap). If placement is correct, but nothing happens, then you need to connect known-good sensor to bike computer and check its operation. If result is negative, the reason is digital unit itself, which will have to be bought new.