Introduction
The Fosmon 113dB Bike Alarm with Remote is designed to provide enhanced security for your bicycle, e-bike, motorcycle, scooter, cart, trailer, and other valuable possessions. This anti-theft system features a loud siren, adjustable sensitivity, and an SOS function to alert you to potential tampering or accidents.
Product Overview
The package includes the main alarm unit, a remote control, and installation accessories.

Image: The main alarm unit and its accompanying remote control.

Image: Contents of the package, including the alarm unit, remote, AAA batteries, a 27A 12V battery, a screwdriver, adhesive pads, and zip ties.
Setup and Installation
The anti-theft vibration alarm is designed for easy setup with two primary installation methods:
- Prepare the Surface: Clean the desired mounting surface thoroughly to ensure proper adhesion.
- Attach the Alarm:
Adhesive Method: Apply the provided adhesive pads to the back of the alarm unit and firmly press it onto the cleaned surface.
Cable Tie Method: Thread cable ties through the brackets on the back of the alarm and secure it to your desired location, such as a bike frame.
- Battery Installation: The alarm unit requires 3 AAA batteries. The remote control uses a 27A 12V battery. Use the provided screwdriver to open the battery compartment and insert the batteries, ensuring correct polarity.

Image: Step-by-step installation guide showing surface cleaning, adhesive/cable tie application, mounting, and arming the alarm.

Image: Visual representation of the two installation methods: using zip ties or double-sided tape.
Operating Instructions
The alarm is operated using the included remote control. An alarm unit can be paired with up to 8 remotes.
Arming the Alarm
Press the Arm button (closed padlock icon) on the remote. The alarm will beep once, and after approximately 5 seconds, it will be fully armed. A second beep confirms it is armed and ready.
Disarming the Alarm
Press the Disarm button (open padlock icon) on the remote. The alarm will beep once, indicating it is disarmed.
Adjusting Sensitivity and Volume
The alarm features 7 different sensitivity levels and 3 volume levels. Refer to the detailed manual for specific button combinations to adjust these settings.
SOS Function
The SOS function detects if the device tilts more than 45° from its original position, signaling an accident. When triggered, it will emit a beeping sound to signal for help.
- To Turn On SOS: The SOS function is off by default. Press and hold the Disarm button for approximately 6 seconds. The LED will turn off and then back on, followed by 5 beeps to indicate SOS is on.
- To Turn Off SOS: Press and hold the Disarm button for 6 seconds. The LED will turn off and then back on, and the alarm will beep 2 times to indicate SOS is off.

Image: Instructions for activating and deactivating the SOS function.
Finding Your Vehicle (Wireless Bike Tracker)
If you need to locate your vehicle, press the bell icon button on the remote. The alarm will emit a loud tone, helping you find it from a distance. The remote control has a range of up to 230 feet (70m).

Image: The remote control's function to help locate your bike with a loud tone.
Key Features
- Loud 113dB Alarm: The alarm produces a powerful 113dB sound to deter thieves. When triggered, the alarm will continue for 30 seconds or until disarmed.
- Vibration Sensor: The alarm responds to vibration or movement when armed.
- IP65 Waterproof Rating: Designed to withstand dust and water splashes, making it suitable for outdoor use.
- Multi-Purpose Use: Can be used for various applications beyond bikes, such as luggage, fences, trailers, and more. It works effectively as an added security layer when used in conjunction with traditional locks.

Image: Explanation of how the alarm detects a nudge (beep) versus continuous movement (full alarm).

Image: Visual representation of the loud 113dB alarm in action, deterring a potential thief.

Image: Examples of the alarm's multi-purpose applications, including motorcycles, luggage, camping gear, and trailers.

Image: Demonstrates using the alarm with existing locks for increased security and the SOS feature for accident alerts.

Image: The alarm's IP65 rating ensures durability against dust and water.

Image: Wide range of applications for the alarm, including bicycles, motorcycles, scooters, and trailers.
Official Product Video
Video: An official product video demonstrating the Fosmon Anti Theft Bike Alarm with Remote in various scenarios, including its sensitivity and loud alarm sound. This video is provided by the seller, SF Planet.
Maintenance
Battery Replacement
The alarm unit requires 3 AAA batteries and the remote control requires a 27A 12V battery. When the alarm or remote's performance diminishes, replace the batteries. Use the provided screwdriver to open the battery compartments carefully.
For detailed instructions on battery replacement, refer to the video provided below, which offers a practical demonstration of the product's physical aspects and battery access.
Video: A user-generated video demonstrating the physical components of the alarm, including the battery compartment and the tools provided for battery replacement. This video is from a customer review and provides practical insight into the product's physical aspects.
Troubleshooting
- Alarm Not Responding: Check battery levels in both the alarm unit and the remote control. Ensure they are correctly inserted.
- Alarm Too Sensitive/Not Sensitive Enough: Adjust the sensitivity level using the remote control as described in the operating instructions.
- Alarm Not Loud Enough: Adjust the volume level using the remote control. Ensure the alarm's speaker is not obstructed.
- False Alarms: Reduce the sensitivity setting. Ensure the alarm is mounted securely and not subject to excessive vibrations from external sources (e.g., strong winds, passing heavy vehicles).
Specifications
| Feature | Detail |
|---|---|
| Item Weight | 4 ounces |
| Product Dimensions | 3.74 x 1.65 x 0.9 inches |
| Item Model Number | 51087HOM |
| Batteries (Alarm Unit) | 3 AAA batteries required |
| Batteries (Remote) | 1 27A 12V battery required |
| Wireless Remote | Yes |
| Maximum Range (Remote) | 90 Feet |
| Noise Level | 113 dB |
| Waterproof Rating | IP65 |
Warranty and Support
This product comes with a limited lifetime warranty. For more information regarding warranty claims or technical support, please refer to Fosmon’s official website or contact their customer service.
Fosmon provides 24/7 free customer support.





