Introduction
This manual provides detailed instructions for the installation, operation, and maintenance of your SIGMA Bicycle Computer, model 03100. Designed for cyclists, this compact and lightweight device offers essential cycling data with reliable STS digital coded transmission.
Setup and Installation
Proper installation ensures accurate data collection and optimal performance of your bicycle computer.
1. Package Contents
- SIGMA Bicycle Computer (Display Unit)
- Speed Sensor (STS digital coded)
- Wheel Magnet
- Mounting Bracket for Handlebar/Stem
- Mounting Material (O-rings/zip ties)
- CR2032 Battery (pre-installed or included)
2. Battery Installation
The device comes with a CR2032 lithium metal battery. If not pre-installed, open the battery compartment on the back of the display unit using a coin, insert the battery with the positive (+) side facing up, and close the compartment securely.
3. Mounting the Display Unit
Attach the mounting bracket to your bicycle's handlebar or stem using the provided O-rings or zip ties. Ensure it is securely fastened and positioned for easy viewing. The display unit slides onto the bracket until it clicks into place.

Image: The SIGMA bicycle computer display unit securely mounted on a bicycle handlebar, ready for use.
4. Mounting the Speed Sensor and Magnet
Mount the speed sensor to the front fork of your bicycle using the provided mounting material. Position it so that the sensor aligns with the wheel magnet. Attach the magnet to a spoke on your front wheel. Ensure the gap between the sensor and the magnet is approximately 2-5 mm when the wheel rotates. The sensor should be positioned to detect the magnet passing by.
5. Wheel Size Setting
Accurate speed and distance readings depend on correct wheel size calibration. Refer to the table below or the user manual for predefined wheel circumference values. You can also manually enter the circumference in millimeters for precise calibration.
| Wheel Size (Inches) | Circumference (mm) |
|---|---|
| 16" | 1272 |
| 18" | 1436 |
| 20" | 1596 |
| 22" | 1759 |
| 24" | 1916 |
| 26" | 2073 |
| 27" | 2155 |
| 27.5" | 2210 |
| 28" (700C) | 2242 |
| 29" | 2326 |
To set the wheel size, press and hold the button on the bottom of the display unit until the setting mode is activated. Use short presses to cycle through digits and long presses to confirm and move to the next digit/setting.
Operating the Bicycle Computer
The SIGMA bicycle computer features a clear LCD display and a single button for easy navigation and function selection.
Display Overview

Image: The clear LCD display of the SIGMA bicycle computer, showing current speed (km/h), trip distance (km), and ride time (H).
The 1.9-inch LCD display simultaneously shows key cycling data, including:
- Current Speed: Displayed prominently in km/h or mph (selectable).
- Trip Distance: The distance covered during the current ride.
- Ride Time: The duration of the current ride.
- Note: The device is designed to show all primary data without requiring constant switching.
Button Functions
The single button located on the bottom of the display unit controls all functions:
- Short Press: Cycles through available display modes or confirms selections in setting menus.
- Long Press: Enters or exits setting modes, resets trip data, or confirms advanced settings.
To reset trip data (distance and time), ensure the device is in the main display mode, then press and hold the button until the values reset to zero.
Maintenance
Regular maintenance ensures the longevity and accuracy of your SIGMA Bicycle Computer.
Cleaning
Wipe the display unit and sensor with a soft, damp cloth. Do not use abrasive cleaners or solvents, as these can damage the plastic and electronic components. The device is designed to be water-resistant for typical cycling conditions, but avoid submerging it in water.
Battery Replacement
The display unit uses a CR2032 battery with an approximate life of 2 years. When the display becomes dim or erratic, it's time to replace the battery. Follow the battery installation steps outlined in the "Setup and Installation" section. Dispose of old batteries responsibly according to local regulations.
Troubleshooting
If you encounter issues with your bicycle computer, refer to the common problems and solutions below.
- No Speed/Distance Reading:
- Check the alignment and gap (2-5 mm) between the speed sensor and the wheel magnet.
- Ensure the magnet is securely attached to the spoke.
- Verify the battery in the display unit is correctly installed and has sufficient charge.
- Confirm the wheel size setting is correct.
- Inaccurate Readings:
- Re-check the wheel size setting for accuracy. Even a small error can lead to significant discrepancies over distance.
- Ensure the sensor and magnet are not loose or shifting during rides.
- Display Not Working:
- Check the battery. Replace if necessary.
- Ensure the display unit is properly seated in its mounting bracket.
If problems persist after attempting these solutions, please contact SIGMA customer support.
Specifications
| Feature | Detail |
|---|---|
| Model Number | 03100 |
| Brand | Sigma |
| Color | Black |
| Display Type | LCD |
| Display Size | 1.9 Inches |
| Connectivity Technology | Wireless (STS digital coded transmission) |
| Sensor Type | Speed Sensor |
| Battery Type | CR2032 Lithium Metal (included) |
| Battery Life | Approx. 2 years |
| Dimensions (L x W x H) | 30L x 30W x 70H millimeters |
| Weight | 23 grams |
| Main Material | Plastic |
| Included Components | Speedometer |
Warranty
The SIGMA Bicycle Computer model 03100 comes with a spare parts availability period of 2 years from the date of purchase. This indicates the duration for which replacement parts are expected to be available. For specific warranty terms and conditions, please refer to the official warranty documentation provided with your product or visit the manufacturer's website.
Support
For further assistance, technical support, or inquiries regarding your SIGMA Bicycle Computer, please visit the official SIGMA Sport website or contact their customer service department. Contact information can typically be found on the product packaging or the manufacturer's website.





