Cycle computers measure ride data -- everything from current speed, average speed and distance travelled, to heart rate and power output. While there are two basic types of computer -- wired and wireless -- the price and feature-set may vary significantly between models. Though the sheer variety of computers may seem daunting, each type of computer attaches to the bicycle in the same basic manner.
In a well-lit room, stabilise the bicycle such that the front fork, wheel and handlebars can be worked on without risk of the bicycle falling over. A bike stand works well for this purpose, as does a stationary trainer.
Remove the computer from the packaging and note all the included accessories.
Clean the front fork and handlebar with a damp rag. Make sure the surfaces are free of grease and dirt. Let dry.
Mount the speed sensor near the bottom of the right fork leg using the zip ties and, if necessary, the rubber shims. Make sure the sensor is stable.
Follow this step if the computer is wired. Proceed to Step 3 if you are using a wireless computer.
Carefully pull taught the wire connecting the speed sensor to the computer mount. Run the wire up the outside of the fork leg and secure it with one or two zip ties.
Wrap the wire around the front brake housing such that the computer mount reaches the handlebar. Wrapping the wire using this technique ensures that it will not become snagged or pull loose during future use.
Secure the computer mount on the handlebar or stem using zip ties and, if necessary, rubber shims.
Some riders prefer to keep their handlebars free for other accessories. The choice of mounting position is personal preference.
Install the computer magnet on a right side spoke such that it passes within 2mm of the speed sensor when the wheel is rotated.
While there are many varieties of computer magnets it is crucial for proper computer function to minimise the distance between it and the speed sensor.
Programming the computer.
Each cycling computer -- even different models from the same brand -- comes with explicit instructions as to proper initial set-up.
Read the manual thoroughly.
Many brands publish manuals on the Internet in case the hard copy is misplaced. Search the brand's website for such information.
It is important to know the size of your bicycle wheel when programming your computer for the first time. The size is moulded into the side of your tire. It might read 700x28c or 26x2.1 or 27x1 1/4. These measurements are crucial for initial set-up and ensure accurate speed measurement. If the computer turns on but doesn't register any data, check the front wheel sensor/front wheel magnet alignment. Make sure there is no more than 2mm between the magnet and sensor. Replacing a cycling computer battery usually results in a complete data reset. Record your data on paper before replacing the battery as many computers allow manual re-entry of cumulative mileage.