1. Introduction
This manual provides essential information for the proper installation, operation, and maintenance of your AKOYU 120dB Anti-Theft Bike Alarm. Please read this manual thoroughly before using the product to ensure optimal performance and safety.
2. Package Contents
Verify that all items listed below are included in your package:
- 1x AKOYU Bike Alarm Unit (Model ZD51)
- 1x Remote Control (Model RC531)
- 3x AAA Batteries (for alarm unit)
- Installation Accessories (zip ties, bracket, screws, double-sided tape, prying tool)
- User Manual

Image: Contents of the AKOYU Bike Alarm package, including the alarm unit, remote, batteries, and installation hardware.

Image: Close-up of the installation accessories, including zip ties, mounting bracket, screws, and double-sided adhesive pads.
3. Setup
3.1 Battery Installation
- Locate the battery compartment on the back of the alarm unit.
- Use the provided prying tool or a small screwdriver to carefully open the battery cover.
- Insert 3 AAA batteries, ensuring correct polarity (+/-).
- Replace the battery cover and secure it.
Video: Demonstrates how to open the battery compartment, insert the AAA batteries, and close the cover for the AKOYU Bike Alarm unit.
3.2 Mounting the Alarm Unit
The AKOYU Bike Alarm offers three installation methods:
- Zip Ties Installation: Secure the alarm unit to your bike frame or seat post using the provided zip ties.
- Bracket Installation: Attach the mounting bracket to your bike, then slide the alarm unit onto the bracket.
- Double-Sided Tape Installation: Use the adhesive pads to attach the alarm unit directly to a flat surface on your bike.

Image: Visual guide illustrating the three different ways to install the alarm unit on a bicycle.
Video: Demonstrates the installation process of the AKOYU Bike Alarm using both zip ties and the mounting bracket on a bicycle.
4. Operating Instructions
4.1 Remote Control Functions
The remote control has four buttons:
- Arming Key (Locked icon): Activates the alarm. The alarm will be armed after a 5-second delay.
- Disarming Key (Unlocked icon): Deactivates the alarm.
- Switch Volume & Mute Key (Speaker icon): Cycles through different volume levels and mute mode.
- Emergency Call / Remote Car Search Key (Triangle with exclamation mark): Triggers an immediate alarm sound to locate your bike or deter potential thieves.

Image: Detailed view of the remote control with labels for each button's function.
4.2 Arming and Disarming the Alarm
- To arm the alarm, press the Arming Key (locked icon) on the remote control. The alarm will beep once and activate after a 5-second delay.
- To disarm the alarm, press the Disarming Key (unlocked icon) on the remote control. The alarm will beep twice and deactivate.
4.3 Adjusting Volume
Press the Switch Volume & Mute Key (speaker icon) on the remote control to cycle through three adjustable volume levels (Level 1, Level 2, Level 3) and a mute mode. The maximum volume is 120dB.

Image: Visual representation of the alarm's adjustable volume settings.
5. Settings
5.1 Adjusting Sensitivity
The alarm features 7 levels of adjustable sensitivity to suit different environments and preferences.
- Short press the Disarming Key on the remote control.
- Press the Disarming Key and Arming Key simultaneously to enter the vibration sensitivity adjustment state.
- Press the Arming Key to increase vibration sensitivity.
- Press the Emergency Call / Remote Car Search Key to decrease vibration sensitivity.
- Press the Switch Volume & Mute Key and Emergency Call / Remote Car Search Key simultaneously to exit the sensitivity setting mode.

Image: Graphical representation of the 7 sensitivity levels.
5.2 Alarm Mode (Light Settings)
The alarm unit has different light modes. To switch between them:
- Press the Disarming Key on the remote control to set the alarm to the disarm state.
- Press the gray mode button on the front of the alarm unit to cycle through:
- Flash Light Mode
- LED Always On Mode
6. Maintenance
- Battery Replacement: Replace AAA batteries in the alarm unit when the alarm sound becomes weak or the unit fails to respond. The remote control uses a CR2032 button cell battery (not explicitly mentioned in specs, but common for remotes).
- Cleaning: Wipe the alarm unit and remote control with a soft, dry cloth. Do not use harsh chemicals or abrasive cleaners.
- Water Resistance: The alarm unit features an IP65 waterproof design, making it resistant to splashes and rain. However, avoid submerging it in water.

Image: The bike alarm unit installed on a bicycle, demonstrating its water-resistant properties.
7. Troubleshooting
- Alarm not responding to remote:
- Check if the alarm unit batteries are depleted and replace them if necessary.
- Ensure the remote control battery is functional.
- Verify that the remote is within the effective range (up to 328 feet).
- Alarm is too sensitive or not sensitive enough:
- Adjust the vibration sensitivity settings as described in Section 5.1.
- Alarm sounds unexpectedly:
- Reduce the vibration sensitivity.
- Ensure the alarm is securely mounted and not subject to accidental triggers.
8. Specifications
| Feature | Specification |
|---|---|
| Brand | AKOYU |
| Model | ZD51+RC531 |
| Noise Level | 120 Decibels |
| Control Method | Remote |
| Maximum Remote Range | 328 Feet |
| Sensor Technology | Ultrasonic Sensor |
| Power Source | Battery Powered |
| Alarm Unit Batteries | 3 AAA batteries (included) |
| Item Weight | 5.9 ounces |
| Package Dimensions | 4.53 x 2.52 x 2.24 inches |
9. Warranty and Support
For warranty information and customer support, please refer to the product packaging or contact AKOYU customer service directly. Keep your purchase receipt for warranty claims.